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The effects of supervised aerobic and resistance
exercise training on Sri Lankan adults with type 2
diabetes mellitus
Sri Lanka Diabetes Aerobic and Resistance Training (SL-DART) Study
A thesis submitted in fulfilment of the requirements of the degree
of Doctor of Philosophy
Submitted by
Dilip Chathuranga Ranasinghe
MBBS (Col/Sri Lanka), D. Sp. Med. (Col/Sri Lanka)
Student number: N 9304177
School of Exercise and Nutrition Sciences
Institute of Health and Biomedical Innovation
Queensland University of Technology, Australia.
&
Faculty of Medicine
University of Colombo, Sri Lanka.
December 2017
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Keywords
Aerobic exercise, resistance exercise, physical activity, Sri Lanka, South Asia, Type 2
diabetes mellitus, randomised controlled study, exercise adherence, compliance, behavioural
change, blood glucose, Glycaemia, Glycosylated haemoglobin, HbA1C, body composition,
% body fat, adiposity, cardiovascular endurance, fitness, strength, lipids, liver enzymes, C
reactive protein, eating behaviour, food preferences, ‘liking’ and ‘wanting’, and quality of
life.
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Abstract
Type 2 diabetes mellitus (T2DM) and the associated cardiovascular diseases (CVD) are
contributing to rising global mortality [1]. South Asia is the home to almost one-fifth of the
world’s population [2]. South Asians are more prone to T2DM compared to other ethnicities
[3].There is a high prevalence of diabetes (10-15%) in South Asian Sri Lankans [4] who are
at a greater risk of CVD [5].
Exercise is known to improve blood glucose, lipid profiles, blood pressure [6] and visceral
adiposity [7] which are goals of diabetes management. Aerobic exercise training (AT)
interventions have been studied widely; resistance exercises training (RT) interventions are
becoming more prevalent. Some recommendations involve combining AT and RT
interventions for the management and prevention of T2DM [9, 10]. Currently there are no
documented studies in Sri Lanka and limited studies conducted in South Asia, comparing the
effects of AT with RT on people with T2DM on glycemic control, visceral adiposity
(anthropometric), liver enzymes and, blood lipid profiles (biochemical).
This thesis is novel because, to the best of my knowledge, there is no comparison of the
effects of RT and AT on physiological and behavioural parameters in Sri Lankans. Studies
tend to be conducted in White Caucasians who have a different body composition to South
Asians. Secondly, the addition of a qualitative study to assess the barriers and facilitators for
compliance and adherence to exercise has not been documented to date.
The Randomized Controlled Trial (RCT) of the SL-DARTS recruited sedentary Sri Lankans
(age 35-65 years) with T2DM (HbA1c 6.5-11.0%) from medical and diabetic clinics of the
National Hospital of Sri Lanka (NHSL) and selected private sector clinics in the capital city,
Colombo. They were randomized into aerobic training (AT), resistance training (RT) and
control (CN) groups. Supervised progressive exercises were conducted 2 days/week for 3
months.
Mean absolute changes in glycemic control (HbA1c) and percentage body fat were the
primary outcomes. The change in glycaemia and insulin resistance (fasting blood sugar/FBS
and fasting insulin/FI) lipid profile, liver enzymes, chronic inflammatory state,
anthropometric measures (height, weight, body mass index/BMI, and waist / hip / mid-thigh /
mid-arm circumferences), muscular strength, cardiovascular endurance, blood pressure, food
preference, Quality of life, were secondary measures. All outcomes were measured within
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one week before the start date of the intervention (pre) and within one week after the
intervention (post).
A qualitative study using in-depth interviews was conducted to assess the experiences of the
participants who completed the program. The themes discussed in the in-depth interviews
were selected based on a critical literature review that was conducted on evidence-based
cognitive behavioural approaches on exercise adoption and adherence.
The protocol was approved by the Ethics Review Committee Faculty of Medicine University
of Colombo (EC/14/071) Sri Lanka and the University Human Research Ethics Committee
(UHREC) Queensland University of Technology (1600000766) Australia. The RCT was
registered in Sri Lanka Clinical Trials Registry; SLCTR/2016/017.
Eighty-six participants (n=AT: 28, RT: 28, CN: 30) completed the intervention, of which
53% were females. The mean age, weight, height and BMI of the participants were 50.1 years
(SE ± 8.7 years), 67.7 kg (SE ± 11.2; M/ F:70.4/65.9 kg), 1.6 m (SE ± 0.2; M/ F: 1.7/1.5 m)
and 26.4 kg/m2 (SE ± 4.1; M/ F: 24.9/27.5 kg/m2), respectively. Most participants were
overweight or obese (M/ F, 29/40) with high prevalence of central obesity. Percentage body
fat (DXA) relative to BMI for males and females were 30.2%/24.9 kgm-2: 41.5%/27.4 kgm-2.
Percentage body fat
Change in mean absolute body weight and BMI was minimal among groups. The absolute
change in %BF in RT, AT and CN were 0.11/0.54/0.04% for DXA and 1.0/1.8/0.1% for Skin
fold (SF) measures, respectively. Changes in %BF by DXA in AT vs. CN: 0.5% (95% CI, -
0.5 to 1.4%) compared to RT vs. CN: 0.06% (95% CI, -0.8 to 1.0%) was higher with no
statistical significance. For SF measures the change was higher with a statistical significance.
RT vs. CN was 0.9% (95% CI, -0.8 to 2.1%) and AT vs. CN was 1.7% (95% CI, 0.5 to 2.7%,
p<0.05).
The mean total fat mass measured by DXA showed a reduction among intervention groups
(AT>RT) 0.562 kg (95% CI, -0.4 to 1.5 kg) vs. 0.314 kg (95% CI, -0.6 to 1.2 kg) compared
to CN. The CN group gained 0.166 kg of fat mass (95% CI, -0.1 to -0.6 kg). There was a
reduction in mean absolute skin fold thickness in all seven sites in both intervention groups
compared with CN. Changes in mid-axilla, subscapular, supra iliac sites in AT and chest,
mid-thigh in RT were higher (p<0.05).
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Glycaemia
The absolute change in HbA1c in RT, AT and CN were 0.6/0.74/0.52% respectively. The
change in HbA1c in RT vs. CN was 0.08% (95% CI, -0.7% to 0.8%, p= 0.87) and AT vs. CN
was higher 0.22% (95% CI, -0.5% to 0.9%. p=0.82) with no statistical significance.
The baseline HbA1c levels varied between the groups. The CN group had a higher baseline
value. A subgroup analysis was conducted by dividing participants into two groups; baseline
HbA1c equal to or more than 7.5% (poorly controlled) and baseline HbA1c less than 7.5%
(tightly controlled). In the poorly controlled T2DM group (HbA1c >7.5%), the absolute
change in HbA1c in the RT (mean HbA1c 8.8%, SE±0.2) vs. CN (mean HbA1c 9.2%,
SE±0.2) was higher than AT (mean HbA1c 8.7%, SE±0.2) vs. CN which was 0.57%: 0.37%,
p>0.05 respectively in contrast to the total group comparison. Baseline values of these groups
were similar.
The AT group reduced TC, HDL, LDL and increased TG levels, but not statistically
significantly. These changes were negligible compared to the changes in the control. RT
showed increase in all parameters where in TC, LDL and HDL showed a significant increase
compared to control (p<0.05).
The RT group reduced AST and increased ALT levels, whereas AT group increased both
AST and ALT levels compared to control. The hs-CRP levels reduced in all groups. All
changes were not statistically significant (p>0.05).
The RT showed a marked post intervention absolute increase in mean distance covered (-
34.5m, 95% CI; -6.1 to -62.8 m) in the 6MWT compared to the control group (11m, 95% CI;
18.1 to -40.1 m), whereas the AT did not (AT distance covered; -24.6m, 95% CI; -7.1 to -
42.1 m). AT change compared to CN was 1.1m (95% CI; 20.5 to -22.7 m).
The resistance group increased muscle strength (RT>AT) significantly compared to the
control in all measured muscle groups: Biceps curl; – 2.8 lbs. ( 95% CI; -5.3 to -0.2 lbs.,14%
increase p<0.05) : Shoulder press; -4.5kg ( 95% CI; -0.8 to -1.2 kg , 22.5% increase, p<0.05)
and Leg press; -9.3 kg ( 95% CI; -18.9 to 0.5 kg , 10.3% increase, p<0.05). The AT
increased muscle strength in the leg press similarly; -9.2 kg (95% CI; -19.7 to 0.9 kg, 10.2%
increase, p<0.05).
The exercise groups reduced explicit liking for all food types. However, the AT group only
increased for high-fat non-sweet food (HFNS). The RT reduced liking for high-fat non-sweet
food (HFSW) significantly and the AT group reduced liking for low-fat non-sweet food
(LFNS). The CN group increased liking for all foods with a greater increase for high fat
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sweet foods (HFSW). Both exercise groups reduced their explicit wanting for all types of
food except HFNS food. The CN group increased wanting for all food types; the increase for
HFSW foods was marked. RT markedly increased implicit wanting for HFNS foods and
reduced for sweet foods.
Quality of Life increased in all the scales (8) for both RT and AT. The RT improved in
physical functioning, role limitations due to physical health, role limitations due to emotional
health, emotional wellbeing and pain, with a medium effect size. The AT improved in:
physical functioning, emotional wellbeing, social functioning and general health, with
medium to large effects sizes. With the exception of three scales (role limitations due to
emotional health, emotional wellbeing, energy), the CN group also increased in all scales,
with small effect sizes.
Adherence to exercise
Contemplation as a stage of behavior change was the main reason for adoption of exercise
and the positive belief they have towards the ‘prescriber’ made a significant impact on
adoption and later the adherence. The facilitators for adherence were; the positive physical
and emotional feedback (arousal) they got from attending the sessions, improved self-
efficacy via verbal persuasions, the performance mastery for exercise developed within the
person, support provided to each individual in various ways and the mutual collaborations/
connections made with the research group (autonomy, belongingness, relatedness).The
barriers were family events, work commitments and the distance from, and accessibility to the
gymnasium. Barriers and facilitators were similar for participants in both training groups.
This study has proven that, despite cultural challenges and barriers, it is possible to conduct a
large-scale exercise intervention trial in Sri Lankans. The results of this thesis demonstrate
that there is some merit in using AT or RT to promote improvements in body composition
and HbA1c in Sri Lankans with T2DM.
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Table of Contents
Keywords: ................................................................................................................................... i
ABSTRACT:.............................................................................................................................. ii
List of Publications ................................................................................................................ viii
List of Figures ........................................................................................................................... ix
List of Tables ............................................................................................................................ xi
List of Abbreviations ...............................................................................................................xii
Statement of Original Authorship ......................................................................................... xiii
Acknowledgments................................................................................................................... xiv
CHAPTER 1: INTRODUCTION. ............................................................................................. 1
CHAPTER 2: LITERATURE REVIEW ................................................................................... 8
2.1 Diabetes mellitus (DM)............................................................................................ 8
2.2 Management of Type 2 Diabetes mellitus (T2DM) ............................................... 10
2.3 Exercise as a management option of T2DM .......................................................... 11
2.4 Exercise,Glycemic control and Insulin resistance ................................................. 16
2.5 Exercise, Body Composition and Adiposity .......................................................... 25
2.6 Effects of exercise in metabolic parameters .......................................................... 30
2.7 T2DM and Physical fitness .................................................................................... 35
2.8 Exercise, liking and wanting for food .................................................................... 38
2.9 Exercise on Quality of Life (QoL) ........................................................................ 42
2.10 Compliance/adherence to exercise and behavior change .................................... 44
2.11 Summary of gaps in literature and research questions ........................................ 46
2.12 Questions and Hypotheses .................................................................................. 48
CHAPTER 3: GENERAL METHADOLOGY ....................................................................... 51
3.1 Objectives .............................................................................................................. 51
3.2 Methodology and Research Plan .......................................................................... 51
3.2.1 Settings ................................................................................................................ 51
3.2.2 Funding ............................................................................................................... 51
3.2.3 Study design and Duration .................................................................................. 52
3.2.4 Preliminary work and Pilot study: ..................................................................... 52
3.2.5 Study 1: Randomized Controlled Trial (RCT) ................................................... 57
3.2.5.1 Trial registration................................................................................... 57
3.2.5.2 Study population and sampling ............................................................ 57
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3.2.5.3 Inclusion and Exclusion criteria........................................................... 57
3.2.5.4 Informed consent ................................................................................. 58
3.2.5.5 Sample size .......................................................................................... 58
3.2.5.6 Randomization ..................................................................................... 58
3.2.5.7 Blinding................................................................................................ 59
3.2.5.8 Study instruments ................................................................................ 61
3.2.5.9 Screening.............................................................................................. 62
3.2.5.10 Intervention ........................................................................................ 62
3.2.5.11 Outcome measures ............................................................................. 66
3.2.6 Study 2: Qualitative study- Methadology ........................................................... 74
3.2.7 Data and Statistical analysis................................................................................ 75
CHAPTER 4: RESULTS & DISCUSSION- STUDY 1
Randomized Controlled Trial - The effects of supervised aerobic and resistance exercise
training on Sri Lankan adults with type 2 diabetes mellitus ................................................... 77
4.0 Recruitment, Intervention and General Characteristics ...................................... 77
4.1 Results: Glycemic changes ................................................................................... 84
4.2 Results: Adiposity and anthropometrics ............................................................... 95
4.3 Results: Metabolic parameters ............................................................................. 114
4.4 Results: Physical fitness parameters .................................................................... 120
4.5 Results: Liking and Wanting for food ............................................................... 126
4.6 Results: Quality of Life ....................................................................................... 133
4.7 DISCUSSION- STUDY 1 (RCT) ....................................................................... 136
CHAPTER 5: STUDY 2
Qualitative study - Barriers and facilitators for adherance to the intervention
5.1 Introduction .......................................................................................................... 153
5.2 Primary outcome ................................................................................................. 154
5.3 Methodology ....................................................................................................... 154
5.3.1 Critical literature review ................................................................................... 155
5.3.2 In Depth Interviews (IDIs) ................................................................................ 162
5.4 Results .................................................................................................................. 164
5.5 Discussion ............................................................................................................ 174
CHAPTER 6: GENERAL DISCUSSION, FUTURE DIRECTIONS & CONCLUSIONS . 179
7.0 Reference List .................................................................................................................. 189
8.0 Appendix ......................................................................................................................... 212
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List of Publications
Directly related to the thesis:
1. Chathuranga Ranasinghe; Andrew Hills; Godwin Constantine; Graham Finlayson;
Prasad Katulanda; Neil King. Study protocol: A randomized controlled trial of supervised
resistance training versus aerobic training in Sri Lankan adults with type 2 diabetes
mellitus: SL-DART Study. BMC Public Health 2017: Accepted
2. Chathuranga Ranasinghe, Neil A King, Ross Arena, Andrew P Hills. FITTSBALL – a
dynamic tool for supervision of clinical exercise prescription. Journal Disability and
Rehabilitation. Under Review
Related to the thesis:
3. Chathuranga Ranasinghe,Chathurani Sigera, Priyanga Ranasinghe, Ranil Jayawardena,
Ayodya C. R. Ranasinghe, Andrew P. Hills and Neil King. Physical inactivity among
physiotherapy undergraduates: exploring the knowledge-practice gap. BMC Sports
Science, Medicine and Rehabilitation 2016, 8:39.
Not related to the thesis:
4. Ranasinghe DC, Ranasinghe P, Jayawardena R, Misra A. Physical activity patterns
among South-Asian adults: a Systematic Review. International Journal of Behavioral
Nutrition and Physical Activity. 2013,10:116. doi:10.1186/1479-5868-10-116- (Google
scholar citations 36).
5. DC Ranasinghe, JP Gamage, P Katulanda N Andraweera, KWAS Thilakarathne, P
Tharanga. Relationship between Body Mass Index (BMI) and body fat percentage,
estimated by bioelectrical impedance, in a group of Sri Lankan adults: a cross sectional
study. BMC Public Health. 2013(1): p. 797. (Google scholar citations 47).
6. Chathuranga Ranasinghe, Priyanga Ranasinghe, Ranil Jayawardena, Rezvi Sheriff,
David R. Matthews, Prasad Katulanda. Evaluation of physical activity among adults with
Diabetes Mellitus from Sri Lanka. International Archives of Medicine. 2014, 7:15.
(Google scholar citations 7).
7. P Katulanda, DC Ranasinghe, KGNS Karunaratne, R Sheriff, DR Matthews. Prevalence
patterns and correlates of alcohol consumption and its’ association with tobacco smoking
among Sri Lankan adults: a cross sectional study. BMC Public Health 2014, 14:612.
(Google scholar citations 10).
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List of Figures
Figure 1.1 Activities of SL-DARTS, A schematic overview of the structure, locations and
health professionals involved in development and data collection
Figure 3.1 Research plan
Figure 3.2 Flow chart of sampling, recruitment and progression of RCT/Study 1
Figure 3.3 Specific data collection time points in the program
Figure 4.1.1 Participant flow diagram
Figure 4.1.2 (a) Mean changes in HbA1c
Figure 4.1.2 (b) Mean changes in HbA1c in participants with HbA1c < 7.5%
Figure 4.1.2 (c) Mean changes in HbA1c in participants with HbA1c > 7.5%
Figure 4.1.3 Individual profiles of changes in HbA1c
Figure 4.1.4 (a) Mean changes in FBS
Figure 4.1.4 (b) Mean change in FBS in participants with HbA1c < 7.5%
Figure 4.1.4 (c) Mean changes in FBS in participants with HbA1c > 7.5%
Figure 4.1.5 (a) Mean changes in FI
Figure 4.1.5 (b) Mean changes in FI in participants with HbA1c < 7.5%
Figure 4.1.5 (c) Mean changes in FI in participants with HbA1c > 7.5%
Figure 4.1.6 (a) Mean changes in HOMA-IR
Figure 4.1.6 (b) Mean changes in HOMA-IR in participants with HbA1c < 7.5%
Figure 4.1.6 (c) Mean changes in HOMA-IR in participants with HbA1c >7.5%
Figure 4.2.1 (a) Mean changes in body weight
Figure 4.2.1 (b) Mean changes in BMI
Figure 4.2.2 Individual profiles of changes in body weight
Figure 4.2.3 Mean changes in Girths and Circumferences
Figure 4.2.3 (a) Mean changes in Waist Circumference
Figure 4.2.3 (b) Mean changes in Hip Circumference
Figure 4.2.3 (c) Mean changes in Waist: Hip ratios
Figure 4.2.3 (d) Mean changes in Mid Arm Circumference
Figure 4.2.3 (e) Mean changes in Mid-Thigh Circumference
Figure 4.2.4 (a) Mean changes in % total body fat by DXA
Figure 4.2.4 (b) Mean changes in % total body fat by skin fold thickness
Figure 4.2.4 (c) Mean changes in fat mass by DXA
Figure 4.2.4 (d) Mean changes in fat free mass by DXA
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Figure 4.2.5 Individual profile of changes in total body fat mass (DXA)
Figure 4.2.6 (a) Mean changes in triceps skin fold thickness
Figure 4.2.6 (b) Mean changes in chest skin fold thickness
Figure 4.2.6 (c) Mean changes in axillary skin fold thickness
Figure 4.2.6 (d) Mean changes in scapular skin fold thickness
Figure 4.2.6 (e) Mean changes in abdominal skin fold thickness
Figure 4.2.6 (f) Mean changes in supra iliac skin fold thickness
Figure 4.2.6 (g) Mean changes in thigh skin fold thickness
Figure 4.3.1 (a) Mean changes in HDL levels
Figure 4.3.1 (b) Mean changes in LDL levels
Figure 4.3.1 (c) Mean changes in TG levels
Figure 4.3.1 (d) Mean changes in TC levels
Figure 4.3.2 (a) Mean changes in ALT levels
Figure 4.3.2 (b) Mean changes in AST levels
Figure 4.3.3 Mean changes in hs-CRP levels
Figure 4.4.1 Mean changes in distance covered in 6MWT
Figure 4.4.2 (a) Mean changes in muscular strength (Biceps curl)
Figure 4.4.2 (b) Mean changes in muscular strength (Shoulder press)
Figure 4.4.2 (c) Mean changes in muscular strength (Leg press)
Figure 4.5.1 (a) Mean changes in Explicit Liking for HFSW food
Figure 4.5.1 (b) Mean changes in Explicit Liking for LFSW food
Figure 4.5.1 (c) Mean changes in Explicit Liking for HFNS food
Figure 4.5.1 (d) Mean changes in Explicit Liking for LFNS food
Figure 4.5.2 (a) Mean changes in Explicit Wanting for HFSW food
Figure 4.5.2 (b) Mean changes in Explicit Wanting for LFSW food
Figure 4.5.2 (c) Mean changes in Explicit Wanting for HFNS food
Figure 4.5.2 (d) Mean changes in Explicit Wanting for LFNS food
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List of Tables
Table 1.0 Hypothesized effect of each exercise mode
Table 3.1 List of Sri Lankan foods in the Leeds Food Preference Questionnaire (LFPQ)
Table 4.1.1 Baseline characteristics
Table 4.1.2 Changes to medication during intervention period
Table 4.1.3 Characteristics of the exercise intervention
Table 4.1.4 Changes in Hemoglobin A1c, Fasting blood sugar, Fasting Insulin
Table 4.1.5 Directional changes of variables
Table 4.2.1 Changes in anthropometrics and body composition
Table 4.2.2 Changes in body girths and circumferences
Table 4.2.3 Changes in body composition measured by DXA
Table 4.2.4 Changes in body composition by 7 site skin fold thickness calculation (ACSM)
Table 4.2.5 Comparison in regional body composition with different methods
Table 4.3.1 Changes in Lipid profile, Liver enzymes, and hs-CRP
Table 4.4.1 Changes in cardiovascular parameters and muscular strength
Table 4.4.2 Changes in 3 minute step test in after each stage/ minute
Table 4.5.2 Changes in Explicit Liking for food types
Table 4.5.3 Changes in Explicit Wanting for food types
Table 4.5.4 Changes in Implicit Wanting for food types
Table 4.5.5 Directional changes in hedonic responses to different types of food
Table 4.6.1 Changes in pre and post intervention SF-36 scores across groups
Table 4.6.2 Between groups analysis vs control in QoL
Table 5.1 Themes discussed in the IDIs
Table 5.2 Data from Recruitment and Drop- out registries
Table 6.0 Hypothesized effect of each exercise mode and the results from the study
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List of Abbreviations
T2DM : Type 2 diabetes mellitus
RCT : Randomized controlled trial
RT : Supervised progressive resistance exercise program
AT : Supervised progressive aerobic exercise program
CN : Control group
HbA1c : Glycosylated hemoglobin
FBS : Fasting blood sugar
BGL : Blood glucose level
FI : Fasting Insulin
HOMA-IR : Homeostasis Model Assessment-Insulin Resistance
ALT : Alanine aminotransferase
AST : Aspartate aminotransferase
NAFLD : Nonalcoholic fatty liver disease
hs CRP) : highly sensitive C-Reactive Protein
LFPQ : Leeds Food Preference Questionnaire
QoL : Quality of Life
ACSM : American College of Sports Medicine
HRmax : Maximum Heart Rate
ECG : Electrocardiogram
NCD : Non-Communicable Diseases
UOC : University of Colombo
QUT : Queensland University of Technology
NHSL : National Hospital of Sri Lanka
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Statement of Original Authorship
The work contained in this thesis undertaken between QUT and University of Colombo has
not been previously submitted to meet requirements for an award at these or any other higher
education institution. To the best of my knowledge and belief, the thesis contains no material
previously published or written by another person except where due reference is made.
Dilip Chathuranga Ranasinghe
Date: 14th December 2017
QUT Verified Signature
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Acknowledgements
I would like to take this opportunity to acknowledge the assistance, guidance and inspirations
of numerous people during my PhD studies.
I would like to pay tribute and dedicate this work in remembrance of my father Lalith
Ranasinghe who passed away during the time of the conduct of this study. Thanks dad for
being my pride and showing me path to reach beyond limits. I am in debt to my mother
Sheela who has been my strength and taught me perseverance since I was small. I am
enormously fortunate to have my wife Ayodya always beside me lovingly supporting my
work and taking care of our children while I am away, bearing all difficulties. Love to my
sons Kenul and Ranul and daughter Ayansa for filling my life with joy and taking my stress
off during difficult times and to all my family for supporting throughout.
I could not have asked for better supervisors for my PhD. My principal supervisor Professor
Neil King; who planned my journey with his professionalism and conduct; which I inculcated
during this period. You allowed me freedom to work while keep guiding at all times of need.
Thanks for been incredibly generous providing me with resources and contacts to develop the
study and myself as a professional. You have encouraged me in so many activities, in asking
questions, thinking independently and have been a constant source of reassurance and
honesty. Specially being concerned about my personal difficulties, you extended your support
beyond academic supervision. My gratitude to associate supervisor Professor Andrew Hills
who have given me insight to many areas in the science with your vast experience. Thanks
for providing me with input and reviews with minute details where I learned about the
importance of detailed commitment that I should have towards the subject. My warm thanks
to associate supervisor Dr Prasad Katulanda who has been my teacher since the beginning of
my career at University of Colombo. You introduced me to research and guided me to build
myself as a researcher and a professional. My appreciation is also extended to associate
supervisors Dr Rachel Wood and Dr Graham Fynlayson who has given valuable inputs
during the planning and executing the study.
I would take this opportunity to thank my teachers and colleagues from University of
Colombo. Professor Rohan Jayasekera former Dean Faculty of Medicine had been
inspirational initiating my work in Sports Medicine and Clinical Exercise Physiology.
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Professor Jennifer Perera the current Dean who provides support during difficulties and
encouraged to expand my PhD for applicable opportunities should be remembered with
respect. My thanks to Heads of my department Dr. Ajith Malalasekera for your sincere
advices and Dr Jithangi Wanigasinghe for providing all needed support from the department.
Colleagues of my department especially Dr Romain Perera for his continues support during
the study. Dr Ranil Jayawardena should be reminded with much gratitude who has been a
peer, an adviser, a collaborator and a friend in need even before the beginning of my PhD.
Dr. GR Constantine for his most valuable time dedicated voluntarily as the consultant
cardiologist of the study is appreciated most respectfully.
My special thanks to QUT Sri Lanka Joint/Split PhD program, providing me opportunity to
come to QUT Australia to conduct my PhD as one of its first recipients. Chairman University
Grants Commission (UGC) Sri Lanka, Vice Chancellor University of Colombo, Vice
Chancellor Queensland University of Technology and the staff of those institutions who
provided funding and continues support is highly appreciated. Especially Gayani
Wickramarachhci from UGC, Emma Kirkland and Vivien Kuur from QUT who timely
supported my administrative process when I was away in Sri Lanka was really helpful for my
work. Dr. Tony Sahama who coordinated the program is remembered with respect at this
moment. Also Robbie Mullins, Andrew McWilliam at QUT exercise clinics, Brendon Moy,
my fellow members of the group at IHBI, Leonie Ruddick-Collins, Roslyn Clapperton your
help is much appreciated which made my stay at QUT fruitful an enjoyable.
The Sri Lanka Diabetes Aerobic and Resistance Training Study (SL-DARTS) presented in
this thesis would not have been possible without so many people volunteering to participate
in the study. I am very much in debt to all the participants for being not only so willing to
help out and give up your own time, but also for making the time spent in the exercise
sessions in the gymnasium so much more enjoyable. The dedicated commitment and service
by Buvinie Buddhila, Sabeena Devage, Chanchala Dilrukshi, Janitha Chinthana, Tesmal
Fernando, Buddhima Abewardena as research assistants and Ashoka, Nandana as training
instructors were the main driving forces behind the successful completion of SL-DARTS.
Buvinie and Sabeena your dedication was beyond expectations where participants highly
commended. Voluntary service by Amila Buddhika and the ECG department of NHSL,
University Medical officer Dr Wasudewa and staff at Health Center UOC Thushari, Nilanthi;
are remembered with much gratitude. I am grateful to the Vice Chancellor, Chairman Sports
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Board, and Director Physical Education at UOC for providing me access to the Gymnasium
and Health Center which reduced the cost of the study immensely. My gratitude to Directors
of National Hospital Sri Lanka and Navaloka hospitals for supporting the study; Dammi from
biochemical laboratory and Dilani at the DXA scanning lab who had been most efficacious
providing me with timely accurate data. My sincere thanks should be extended to the
consultants who provided support and access to their clinics during recruitment of
participants.
I would also like to extend my appreciation to my final seminar panel members, external
examiners and manuscript reviewers for providing extremely helpful comments and insights
on various aspects of this thesis. I would also like to acknowledge the work of many people
cited in this thesis and discussions with those I have had the opportunity to meet.
Finally I would remind all my friends and family for your time, advice, encouragement,
humor and interest. Thank you so much for your constant support always.
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Chapter 1: Introduction
Obesity and the cluster of conditions known as the metabolic syndrome (i.e. dysglycemia,
dyslipidemia, hypertension and a pro-coagulant state) are the precursors of type 2 diabetes
mellitus (T2DM) and cardiovascular diseases (CVD) [1]. The prevalence of T2DM and
metabolic syndrome are rising globally and are major causes of premature death via CVD
[12]. The World Health Organization (WHO) projects that T2DM will be the 7th leading
cause of death in 2030, and the impact on the densely populated low-to-middle income
countries of South Asia is predicted to be high [13].
Sri Lanka and most countries in South Asia are presently facing a socio-demographic
transition. The documented prevalence of T2DM (10-15%) [4] with an increase in obesity
and CVD [14] are contributing to increased morbidity and mortality in the Sri Lankan
population. Prevention and management of an estimated 1-1.5 million people with pre-
diabetes and T2DM is causing an escalating burden to the Sri Lankan economy and society.
There is an urgent need to develop effective management strategies to prevent the problem
getting worse.
Sri Lanka and Exercise Culture: ‘setting the scene’
Sri Lanka is a low-to-middle income South Asian country, an island of 65,610 km2 in the
Indian Ocean with a population of 21 million [15]. Being a sovereign state, Sri Lankan
multicultural society is predominantly of ‘Sinhalese’ ethnicity of Asian Indian origin.
The Sri Lankan government and health care workers are investing and planning to combat the
rising non-communicable disease (NCD) epidemic [16]. Optimizing the conventional
management and prevention strategies and the development of novel low-cost interventions
and research are a high priority for academics and clinicians. Exercise, which is known as
one of the first-line management strategies of T2DM is currently promoted by the Sri
Lankan health care workforce as a ‘public health intervention’; whereas, exercise as a
‘therapeutic mode’ for management of T2DM is not evident at policy level [16]. This could
be attributed to the limited evidence of the effects of exercise training on fitness, metabolic
and behavioral parameters of Sri Lankan adults. Randomized controlled trials comparing
these outcomes are sparse even regionally in South Asians and Asian Indians [17].
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Sri Lanka is changing from its early agricultural lifestyle to a more sedentary lifestyle as a
result of socio-demographic transition and industrialization [4]. Physical activity in Sri
Lanka, which had been mainly associated with occupations and agriculture is declining in
urban areas. Participation in recreational sports, once very prevalent among the young, is also
disappearing. Recreational structured exercise has not been a part of the culture in Sri Lanka,
unlike in the developed world. Recreational exercise groups, gymnasiums and trained
professional staff are very limited and typically limited to the cities. Undergraduate
physiotherapy degree programs were progressively introduced to Sri Lanka in the last 10
years. Previously it was a diploma entry pathway to the health sector. There are no
university-driven formative learning pathways or accreditations for physical trainers or
strength and conditioning coaches. Exercise physiologists do not exist as health care
professionals. Being the top ranked research intensive state academic institution in Sri Lanka;
the University of Colombo built a fully equipped strength and conditioning gymnasium for
the first time in 2016.
Historically and culturally, the education system in Sri Lanka did not promote or encourage
students to enter careers in exercise and sports. A qualitative study examining the barriers
and facilitators to engage in exercise in physiotherapy undergraduates at University of
Colombo, Sri Lanka [18], showed lack of motivation from parents and school teachers as one
of the main barriers. The students were encouraged to focus on more academic activity rather
than sports and exercise. Accomplishments and future financial stability was mainly sought
via academic achievements, which compromised the health benefits of exercise. A recent
national study showed that people with T2DM were not active at the recommended level
[19].
Aerobic exercises are currently being promoted as a public health intervention by the
healthcare providers to reduce the unfavorable impacts of growing industrialization and
sedentary lifestyle. This endeavor is being supported by the Sri Lankan government.
However, the promotion of resistance training exercises is not evident among doctors and
healthcare workers, potentially due to lack of evidence in the Sri Lankan population.
Presently, infrastructure development for the public to engage in recreational activity
(development of footpaths and exercise parks in the urban areas) is being carried out by the
government. Despite an increase in public enthusiasm for exercise, the infrastructure and
human resource (e.g., exercise physiologists, physiotherapists and personal trainers) to
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support it, is in its infancy. Commitments from the private sector to invest in infrastructure
and facilities (e.g., gymnasiums and swimming pools) to meet the public demand, is yet to
occur.
I am a medically qualified academic attached to the Faculty of Medicine (FOM) University
of Colombo (UOC) which is the 2nd oldest medical school in South Asia and top ranked in Sri
Lanka (SL)[20, 21]. My clinical specialty is Sports Medicine. The specialty of sports
medicine is developing in Sri Lanka where core areas such as clinical exercise physiology are
yet to be established. I have developed an ongoing collaboration with University of Durham
UK for development of the specialty since 2010. I am one of the first recipients of QUT Sri
Lanka Split PhD program which is offered for the Sri Lankan state academics funded by
QUT and University Grants Commission (UGC) Sri Lanka. The split PhD program involves
spending a minimum of 1 year at both QUT and UOC.
Developing a model
Since there is no service arm for clinical exercise physiology in Sri Lanka, FOM UOC would
be the ideal place to develop it and our teaching hospital National Hospital of Sri Lanka
(NHSL) would be an ideal opportunity to incorporate the service arm. The vision and drive
for my PhD was based on this opportunity. I came to QUT for protocol development and
training in clinical exercise prescription in the first 6 months of the PhD (2015) and returned
to SL for data collection during the next 2 years.
Challenges associated with conducting the study in Sri Lanka
Conducting a randomized controlled study of this magnitude was a daunting task in Sri
Lanka where the infrastructure, personnel and services were not accustomed to cater to the
needs. The estimated high cost for the study was mainly for the blood/radiological
investigations, equipment and personnel. I received funding from 3 sources (UGC, UOC and
QUT) to conduct the study.
The infrastructure of an air-conditioned gymnasium was not available until 2016 in UOC.
Private gymnasiums are very expensive. I had to get special permission from the Vice
Chancellor of the UOC to use the gym and health center for my study since it was originally
only available for use by students and staff of UOC.
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The pre-post intervention measurements were conducted in 3 institutions (see figure 1.0)
located at different locations as all the required facilities were not available at one place.
Coordinating the technicians, participants, payments and approvals needed additional
personnel to cope with the associated work load and facilitate the completion of the study.
The research support group consisted of 7 personnel and additional staff (n=8) who consisted
of research assistants/physiotherapists, exercise instructors, laboratory technicians,
cardiographers, nurses, doctors, consultant physicians and an administrative assistant. The
administrative assistant coordinating the study accounts.
Thesis Structure
Chapter 1: introduction will introduce the main issues and questions that need to be
answered, Sri Lankan social cultural context regard to exercise, my background, the vision,
the challenges associated with conducting the study, and the thesis structure.
Chapter 2: Literature review focuses on the magnitude of the problem of T2DM globally
and in the Sri Lankan context, specifically the current evidence on effects of exercise and
their applications, recent developing arguments/evidence and their contextual applications to
South Asian Sri Lankan ethnicity.
The gaps in the literature are organized according to 3 themes. Theme 1: Current exercise
guidelines are commonly recommended to all ethnicities. Since Sri Lankan and South Asian
metabolic profile is different; there is scope to identify customized exercise recommendations
which will benefit them more. Comparing the effects of different types of exercises on
biochemical, anthropometric and fitness parameters in this novel population is important to
achieve this. Theme 2: Lack of adherence and compliance to exercise is a key problem
associated with assessing the effectiveness of exercise [19]. Identifying the qualitative causes
of non-adherence is important in planning future practical therapeutic and preventive
interventions; these data are limited in South Asian populations. Theme 3: Dietary
preferences and food choice have a strong influence on the development of T2DM and its
management. In addition to energy restriction, food preference and macronutrient
composition are important factors in the dietary management [15]. Knowledge about the
effects of exercise on food preference in people with T2DM is important in planning the diet.
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The research questions were developed from the identified gaps in the literature and the
research hypothesis are presented. The gaps in methodologies currently present in the
existing studies will be discussed and incorporated in the research methodology section.
Chapter 3: General Methodology outlines the methods and protocols used to answer the
research questions. There were two experimental studies: 1) Randomized Controlled Trial
(RCT) and 2) Qualitative study.
The RCT examined the effects of a supervised progressive resistance exercise program and
aerobic exercise program on behavioral, anthropometric, physical fitness, appetite and
biochemical parameters in Sri Lankan adults with T2DM who do not have contraindications
to exercise. The outcomes were compared between each program and a control group who
received standard care. This study forms the major part of the thesis. To the best of my
knowledge, this is the first time aerobic training has been compared with resistance training
in a Sri Lankan population in Sri Lanka, or in South Asia.
Chapter 4: Results - Study 1 - Randomized Controlled Trial - The effects of supervised
aerobic and resistance exercise training on Sri Lankan adults with type 2 diabetes
mellitus describes the main experimental study results. The chapter is arranged into sub
sections by dependent variables; baseline characteristics, glycemic control, anthropometry
and body composition, metabolic parameters, physical fitness, liking and wanting for food,
and quality of life.
Chapter 5: Study 2 - Qualitative study - Barriers and facilitators for adherence to the
program/intervention discusses the second experimental study, the qualitative study.
Chapter 6: General discussion, future directions and conclusions discusses the outcomes
of the two studies, the implications and way forward. The experiences of developing the
study for the first time in Sri Lanka and how it evolved to create “Exercise” as therapeutic
service arm in Sri Lanka are explained. Since the exercise culture and prescribing therapeutic
progressive exercises is novel to Sri Lankan patients and the health care providers, the
process involved a range of novel experiences. These included, planning the intervention in
Australia while relating the experience to Sri Lanka, the concepts, identifying settings,
getting approvals, developing personals and protocols, arranging investigations, reviewing
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evaluating and troubleshooting evolved an ‘Exercise prescription service arm’ to people with
diabetes in Sri Lanka. The study created the awareness of the need for a service of this nature.
The experiences, barriers and strategies to progress and apply the outcomes are also
discussed.
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3. Faculty of Medicine
: 4 km away UOC
University of Colombo
UOC/SL
6. National Hospital Sri
Lanka/NHSL- 4 km away UOC
(Largest Teaching hospital in SL/
>6000 beds)
Training on
Resuscitation
(College of
Anesthelogists)
Recruitment
QUT- Australia
2. Health Center
7. Navaloka Hospital (Tertiary care private hospital)
5km away UOC
Funding bodies 1. University Grants Commission SL
2. University of Colombo SL
3. QUT AUS
Annexure
1. Gymnasium – Intervention/ exercise testing
2. Health Center- Physical examination/LFPQ/Drawing
of blood
3. Faculty of Medicine Department of Allied Health
Sciences- Work Station
4. IHBI- Work station Australia
5. QUT exercise clinics – Clinical training on ex
physiology
6. NHSL Cardiology- Training/2dEco/Ex ECG
7. Navaloka Hospital- DXA/Blood (transported by
courier)/Recruitment
8. Research Assistants/Physiotherapists
9. Physical trainers
10. Technicians/Nurses/Cardiographers/admin
11. PI/Doctors/Consultants
1. Gymnasium
DXA scan Blood lab
4. IHBI
5. QUT
exercise
Clinic
Back up Private
Tertiary care
hospitals (#2)
1. Recruitment
2. Investigations
Cardiology Recruitment
Figure 1.1 Activities of SL-DARTS
A schematic overview: of the structure,
locations and health professionals involved in
development and data collection.
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Chapter 2: Literature Review
Layout of the chapter
The following literature review focuses on: the magnitude of the problem of type 2 diabetes
(T2DM) globally and in the Sri Lankan context specifically, the current evidence on effects
of exercise and their applications, recent developing arguments/evidence and their contextual
applications to Sri Lankans who live in South Asia. Additionally, it provides a review of the
gaps in methodology in research conducted to date. The gaps in the literature are organized
according to 3 themes.
Theme 1: Current exercise recommendations are commonly practiced among people of all
ethnicities. South Asian Sri Lankans are different to other ethnicities in their body
composition, disease and metabolic profiles [3]. There is scope to identify customized
exercise recommendations tailored to their characteristics. Comparing the effects of different
types of exercise on biochemical, anthropometry, and fitness parameters is important to
achieve this.
Theme 2: Lack of adherence and compliance to exercise is a key problem associated with
assessing the effectiveness of exercise [22]. Identifying the qualitative causes of non-
adherence is important in planning future practical therapeutic and preventive interventions
which at present is limited in South Asians.
Theme 3: Dietary preferences and food choices have a strong influence on the development
and management of T2DM. In addition to energy restriction, food preference and
macronutrient composition is an important factor in dietary management [23]. Knowledge
about post-exercise food preferences of people with T2DM is important in planning the diet.
2.1 Diabetes mellitus (DM)
Diabetes mellitus (DM), commonly called ‘diabetes,’ is a chronic non-communicable disease
characterized by hyperglycemia (higher blood glucose levels than normal range) resulting
from abnormalities in insulin secretion, insulin action, or both [6]. Insulin is the regulating
hormone of blood sugar levels in the human body and secreted by the pancreas. Defects in
the pancreas will cause chronic hyperglycemia which is associated with long-term micro-
vascular and macro-vascular damage to organs (especially the eyes, kidneys, nerves, heart
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and brain) [6], leading to complications including myocardial infarction, stroke and
peripheral vascular disease.
DM mainly has two types. In type 1 diabetes mellitus (T1DM), the cause is an absolute
deficiency of insulin secretion due to autoimmune pathologic process occurring in the
pancreas [6]. T2DM is a multifactorial disease caused by a combination of resistance to
insulin action (insulin resistance/IR) and an insufficient compensatory insulin secretory
response by beta cell dysfunction of the pancreas [6]. The predominant mechanism, however,
appears to be different in various ethnic groups, where in Asian Indians it seems to be IR
[24]. In addition there are other subtypes of DM such as Gestational Diabetes Mellitus/GDM
(which occurs during pregnancy), DM due to genetic defects like maturity-onset diabetes of
the young (MODY) ,immune-mediated diabetes, drugs, chemicals or procedures induced
diabetes etc.[25]. But mainly type 2 DM is discussed in this thesis.
Are South Asians more prone to T2DM?
Prevalence of T2DM is rising globally. Sedentary lifestyle, poor dietary habits,
industrialization, rapid socio-demographic changes are considered as causative factors for the
rise [4]. T2DM is more prevalent in South Asia which is home to one fifth of the world
population (1.5 billion) [2]. India currently has the highest global number of diabetes patients
and is identified as the “Diabetes Capital of the World’, with an estimated prevalence of up to
16.8% in urban areas [3]. In Sri Lanka, the prevalence is 15% in urban and 10.3% in rural
areas [4]. About 25 million people of South Asian origin (India, Pakistan, Bangladesh, Nepal,
and Sri Lanka) [2] are estimated to be living outside South Asia and similar prevalence rates
have been reported in migrants in the USA, Canada, and various European countries [3]. This
indicates that South Asian ethnicity is associated with an increased risk of developing T2DM
compared to white Caucasians. South Asians are also reported to develop T2DM at a much
younger age with increased incidence of complications (retinopathy, nephropathy, and
coronary artery and cerebrovascular disease) [3].
Various theories have been proposed to explain these trends. South Asians have a different
body composition than white Caucasians, with relatively thin upper/lower limbs and
increased abdominal adiposity/central obesity, both in the visceral as well as in the deep
subcutaneous compartments (secondary adipose tissue compartment)[3]. Sniderman and
colleagues [26] have proposed the ‘adipose tissue compartment overflow hypothesis’ which
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states that the relatively inactive primary adipose tissue compartment (superficial
subcutaneous tissue) is less developed in South Asians due to climatic influences, resulting in
early expansion of the secondary adipose tissue compartment, especially in the face of excess
energy intake. Increased visceral and deep subcutaneous fat mass are associated with IR and
development of T2DM [3, 27]. Furthermore, South Asians appear to have dysfunctional
adipocytes, leading to a decreased storage capacity for triglycerides/TG and impaired release
of Free Fatty Acids/FFAs, adipokines, and pro inflammatory cytokines, which are thought to
disrupt the insulin-signaling pathway [3] and insulin resistance.
Skeletal muscle and liver are the major tissues where glucose homeostasis occurs [28]. Liver
accounts for about 25-30% of whole body insulin-mediated glucose disposal [29]. Insulin
also stimulates muscle glucose uptake to remove glucose from the blood, and the glucose
taken up is incorporated into glycogen [30]. Muscle glucose uptake accounts for 75–80% of
whole body insulin-stimulated glucose disposal via GLUT 4 [2] (GLUT 4 is a glucose
transporter in the skeletal muscle plasma membrane which improve glucose disposal and
regulation) [31]. Total body muscle mass (relative to body size) seem to independently effect
the insulin sensitivity and glucose disposal [32]. There is evidence that skeletal muscle mass,
or lean body mass, is also lower in South Asians compared to white Caucasians [3].
In 2009, Bhopal and colleagues proposed the ‘mitochondrial efficiency hypothesis’ [2],
stating that energy producing efficiency of mitochondria in South Asians was enhanced to
successfully adapt them to climatic (heat) and other nutritional exposures (especially low-
calorie diets). At the present time mitochondrial efficiency might be maladaptive when South
Asians adopt new lifestyles of low physical activity levels and high consumption of fat and
sugars leading to increased storage of excess energy as adipose tissue.
With the above theories, there is a belief that genetics and/or epigenetics may play a role in
these differences in South Asians, despite the fact that this has yet to be confirmed [3].
2.2 Management of T2DM
Currently, T2DM is managed via medications and lifestyle modification (diet, physical
activity and psychological stress reduction). Diet and physical activity are recognized as first
line in prevention and management. The main objective is to achieve and maintain optimal
blood glucose control. This is to maintain fasting blood glucose (FBG) level at ≤ 126 mg/dl
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and glycosylated hemoglobin (HbA1c) which is the main parameter to monitor long term
glycemic control at < 6.5% (normal values are 4% - 6.5%) [33]. Other objectives of T2DM
management are to maintain optimal blood lipid profiles, blood pressure [6] and visceral
adiposity [7] which also contribute to glucose control and prevention of complications.
Nevertheless, strategies to prevent type 2 diabetes are still insufficient; since decades, a major
purpose of research was to develop reasonable prevention strategies and to specify detailed
pathomechanisms leading to diabetes [34]. With the steady rise of NCDs, health care systems
in many counties are changing from a “Disease” focused to a “Health” oriented model [35].
The importance of investing on lifestyle change and attitudes has gained considerable traction
in the recent past for improved management of the condition. This is consistent with
recognition that traditional ‘medicine focused’ management strategies will not be cost
effective in the future.
In achieving T2DM management objectives, more emphasis could be given to designing less
expensive physical activity/exercise interventions compared to medications which have a
significant cost to the individual and the country. This should be a prioritized management
strategy in low-to-middle income countries like Sri Lanka, where resources are sparse.
2.3 Exercise as a management option of T2DM
Exercise is a subcomponent of physical activity consisting of planned, structured and
repetitive bodily movement with skeletal muscle contraction, undertaken to improve or
maintain one or more components of physical fitness [36]. Historically, exercise and sport
were considered as recreational activities for social interactions of people and societies. With
the rise of NCDs, the scientific and biological importance of exercise was identified [37].
More scientific prescription of exercise to range of age groups and diseases have been
developed [37-39].
Exercise causes an increase in energy expenditure [40]. In the literature two types of
exercises; aerobic/endurance and resistance/strength training are commonly discussed in the
management of T2DM. Effects of these exercises to-date has been mainly studied in white
Caucasians as opposed to South Asian populations [41].
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Aerobic training/exercise (AT)
Aerobic training/exercise (also known as cardiovascular endurance exercise) depends
primarily on the aerobic energy-generating process [42] and uses oxygen via aerobic
metabolism to adequately meet energy demands during exercise.
Over the last few decades, AT has consistently been shown to achieve the management goals
of T2DM such as, improving blood glucose control, insulin sensitivity [43, 44] and visceral
adiposity [44]. It has also shown to reduce other cardiovascular risk factors such as
controlling blood lipids [45] and reducing carotid arterial stiffness [46], endothelial
dysfunction [47] and carotid artery intima media thickness [48]. Recent studies at a cellular
level have demonstrated increased fatty acid transport and oxidation, improved capillary
density and mitochondrial capacity which contribute to improved glucose and lipid regulation
[49]. Apart from improving the above biochemical parameters, AT is also known to improve
behavioral (reducing stress, improving quality of life) and physical fitness (body
composition, endurance / VO2 max) parameters [7].
Resistance training/ exercise (RT)
Resistance exercise or strength training, uses resistance to induce muscular contraction which
builds the strength, anaerobic endurance and size of skeletal muscles as well as improving
bone strength and metabolism [50].
Resistance exercises have recently been recognized as an important therapeutic tool for the
treatment of T2DM [8] which has also been confirmed to be safe and effective for the elderly
[51] and obese [52] individuals. Similar to aerobic exercise, resistance training has been
reported to enhance insulin sensitivity and glycemic control [53].
Skeletal muscles of T2DM patients has metabolic dysfunction caused by insulin resistance,
impaired glycogen synthesis, lipid accumulation and mitochondrial dysfunction [54]. RT-
induced increase in lean muscle mass is directly related to increased insulin sensitivity and
resting metabolic rate (RMR) which improves metabolic health [7]. This has been
particularly beneficial for older individuals with less lean mass, and it is predicted to be
important in populations with less lean mass such as South Asians [55].
Resistance training increases insulin sensitivity via qualitative changes [56] independent of
changes in muscle mass. It causes insulin dependent GLUT 4 translocations [7] and also
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insulin independent contraction dependent GLUT4 translocations improving GLUT4 density
[57] which improve glucose disposal ultimately. RT is also known to modify low oxidative
type 2b muscle fiber to moderate oxidative type 2a fiber, which improves oxidative capacity
and glucose disposal [56].
In addition, RT has other benefits on behavior and physical fitness with the potential to
increase muscle strength [50] and bone mineral density [58] and results in enhanced
functional status and quality of life [51]. This assists in the prevention of sarcopenia and
osteoporosis especially in the elderly.
In both types of exercises, muscular contraction can occur in different intensities and degrees.
The acute form of exercise increases GLUT 4 translocation to sarcolemma membrane,
whereas chronic exercise training increases GLUT 4-mRNA expression which has a long
lasting effect [59, 60]. In addition to this insulin-dependent mechanism, enhanced glucose
uptake into exercising muscle occurs by multiple insulin independent mechanisms. Exercise
training appears to enhance insulin sensitivity by increased post-receptor insulin signaling
[61]; increased insulin-mediated glucose transport appears to be related to enhanced signal
transduction at the level of IRS proteins and PI 3-kinase [62].
However, unlike AT such as walking or jogging, RT is typically dependent on equipment and
knowledge of exercise technique which often requires instruction and supervision. At the
same time there is evidence that RT is better tolerated by the old and T2DM who find
adherence to continuous moderate intensity AT physically challenging [41]. Subsequently,
even though RT could be used therapeutically in a supervised environment, if it is to be a
feasible form of exercise at the population level, research is needed to discover practical,
viable, culturally-acceptable and economically sustainable ways to safely implement it.
With these accumulated evidence mainly from the studies conducted in white Caucasians ,
world authorities concerned with ‘Health and Exercise’ (World Health Organization (WHO),
American College of Sports Medicine (ACSM), American Diabetes Association (ADA) and
Exercise and Sport Science Australia (ESSA)) have recommended both forms of exercise
(AT and RT) individually and in combination for the general public [9] and also for people
with T2DM [8, 10].
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Safe exercise for T2DM
For people with T2DM, considering the associated cardiovascular, neurological and
musculoskeletal risk, the WHO general recommendations were deemed as only for those
‘who do not have contraindications to exercise’ by ACSM, supported by ADA [10] and
ESSA [8]. With these recommendations, systematic reviews [53, 63] have concluded that
implementing progressive exercises to patients should be supervised. Appropriate supervision
will enable them to complete exercises minimizing the risk of injury or negative health
outcomes [63].
The joint position statement by the ACSM and the ADA states the following special
considerations regarding patients with T2DM; especially when there is end organ damage
[10].
Known CVD is not an absolute contraindication; but ischemic heart disease/angina
classified as moderate or high risk should preferably exercise in a supervised cardiac
rehabilitation program, at least initially [64]. For individuals with peripheral arterial
disease (PAD), with and without intermittent claudication and pain in the extremities
during physical activity; a low-to-moderate walking and cycling have been shown to
enhance mobility, functional capacity, exercise pain tolerance and quality of living (QoL)
[65].
Individuals with peripheral neuropathy without acute ulceration may participate in
moderate weight-bearing exercise. Comprehensive foot care including daily inspection of
feet and use of proper footwear is recommended for prevention and early detection of
sores or ulcers. Moderate walking does not increase risk of foot ulcers or re-ulceration
with peripheral neuropathy [10].
Individuals with uncontrolled proliferative retinopathy, retinal hemorrhage/detachment,
history of laser therapy in the eyes should avoid activities that greatly increase intraocular
pressure and hemorrhage risk such as weight lifting and Valsalva maneuver [10].
Autonomic neuropathy should be screened and receive physician approval and possibly
an exercise stress test before exercise initiation [10].
Both AT and RT improve physical function and QoL in individuals with kidney
disease/nephropathy. Although blood pressure increases during exercise may transiently
elevate levels of micro albumin in urine; presence of micro albuminuria per se does not
necessitate exercise restrictions [66]. Resistance exercise training is especially effective in
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improving muscle function and activities of daily living, which are normally severely
affected by later-stage kidney disease [66]. Before beginning an exercise program,
individuals with overt nephropathy should be carefully screened, have physician
approval, and possibly undergo exercise stress testing [67].
Exercise recommendations for people with T2DM: Customized exercises for South
Asians
The exercise recommendations by ACSM and ADA are:
Persons with T2DM should undertake at least 150 min.wk-1 of moderate to vigorous
aerobic exercise distributed across 3 days during the week, with no more than two
consecutive days between bouts of aerobic activity.
In addition to aerobic training, people with T2DM should undertake moderate to
vigorous resistance exercises/training at least 2-3 d·wk−1.
Consistent with guidelines from the ACSM and ADA; Exercise and Sport Science Australia
recommends resistance exercise to be at least 60 min per week [8] (e.g., two 30 min
sessions).
Consistent with these recommendations, a Cochrane review of 14 trials published in 2006
[68] suggested that there is a 0.6% reduction in HbA1c by any type of exercise (including
aerobic, resistance, and both combined) compared with no exercise. RT was added recently
and American Diabetes Association began recommending it in 2006 [69]. Currently the
combined mode of exercise (CE), where AT and RT were implemented at the same time is
identified as more beneficial [70]. Now CE is incorporated in the above guidelines for all
people with T2DM.
Despite the difference in body composition and metabolic profile between Caucasians and
Asian Indians/ South Asians the current exercise recommendations adapted and practiced as
same for all. South Asians might benefit in a more customized exercise recommendation for
them.
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2.4 Exercise, Glycemic control and Insulin resistance
Glycemic control – The main outcome measure
Most of the exercise trials on T2DM to date by default have studied the effect on glycaemia
as the main outcome measure. The effect of different modes of exercise is measured by
monitoring the absolute change in blood glucose levels of the participants.
2.4.1 How to monitor diabetes? What is glycemic control?
Glycemic control is regulation and maintenance of blood glucose levels within normal ranges
which is the main aim of the treatment of diabetes mellitus [71] (by diet, oral hypoglycaemic
agents or parenteral insulin). The long-term glycemic control reduces later incidence of
secondary diabetic complications [72]. Different clinical aspects of glycemic control is
assessed in number of ways. Each method evaluates the blood sugar control at different
aspects of glucose metabolism.
Fasting blood glucose tests provide an indication of the blood glucose levels during the
fasting state. The actual fasting state of a person who take normal 3 meals per day happens in
the last 3-4 hours hour period of time at the end of the night [73]. It is measured by testing
blood after 8-10 hours of overnight fast which assess the baseline blood sugar level [74].
Glycated hemoglobin (HbA1c) is the gold standard measurement for the assessment of long
term glycemic control [75]. Glycated hemoglobin arise from the non-enzymatic attachment
of glucose to hemoglobin in the red blood cell. They are formed and accumulate in the red
cell in proportion to the blood glucose level. Their concentration reflects the long-term
average glucose level. Fasting glucose tests provide an indication of the current glucose
levels, whereas the HbA1c serves as an overall marker of average levels over a period of 2-3
months [75]. Worldwide large scale clinical studies of diabetes have greatly valued HbA1c as
an indicator of glycemic control [73]. Optimal management of T2DM requires an
understanding of the relationships between HbA1c, fasting plasma glucose and postprandial
glucose (the glucose triad), and how these change during development and progression of the
disease [76].
In addition to being tightly associated with diabetes, HbA1c predicts cardiovascular events
among non-diabetic individuals and it may outperform fasting plasma glucose for predicting
cardiovascular disease [77]. In contrast, serum insulin measurement is not used as often,
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despite the fact that it can identify insulin-resistant subjects, which is a strong marker of
future diabetes [78].
2.4.2 What is insulin resistance and its relationship to diabetes?
Insulin is the main hormone which regulate the glucose concentration in the blood. It is a
peptide hormone secreted by the pancreas (β cells of the pancreatic islets of Langerhans) and
maintains normal blood glucose levels by facilitating cellular glucose uptake, regulating
carbohydrate, lipid and protein metabolism and promoting cell division and growth through
its mitogenic effects [29].
Abnormalities of these processes causes insulin resistance (IR) where a normal or elevated
insulin level produces a weak biological response [79]. The overall etiology of insulin
resistance is quite complex, it is known that a disproportionate accumulation of subcutaneous
and abdominal fat contributes to the desensitization of insulin receptors; that is characterized
by an inhibited uptake of glucose within skeletal muscle and an impaired ability to suppress
endogenous glucose production [79]. This phenomena can be common in South Asian T2DM
who have high % body fat. Most cases it is believed to be manifest at the cellular level via
post-receptor defects in insulin signaling.
IR is the most powerful predictor of future development of T2DM and also a therapeutic
target once diabetes is present. Insulin resistance and impaired insulin secretion both
determine whether diabetes occurs, magnitude of the accompanying hyperglycemia and other
metabolic abnormalities which raises its importance as an outcome measurement.
Measurement of Insulin resistance (IR) – Fasting Insulin
IR directly does not determine glycemic control but it provides additional data on the
etiology of hyperglycemia and its progression. Body insulin levels depend on the pancreatic
β-cell effect to glucose concentrations while, glucose concentrations are regulated by insulin-
mediated glucose production via the liver. Thus, deficient β-cell function will echo a
diminished response of β-cell to glucose-stimulated insulin secretion. Similarly, IR is
reflected by the diminished suppressive effect of insulin on hepatic glucose production.
The hyperinsulinemic euglycemic glucose clamp is the gold standard method for the
determination of IR [80], but is impractical as it is labor- and time-intensive [81]. In the fed
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state major insulin dependent glucose influx (75%) happens in the muscle via GLUT4
receptors [29]. The clamp method determines IR at a stimulated state with glucose just like in
the fed state. It has been postulated that the clamp technique measures the muscle insulin
sensitivity [82].
Apart from clamp technique a number of surrogate indices are currently employed, such as
measurement of the fasting insulin (FI) level which has long been considered the most
practical approach [83]. A considerable correlation has been found between fasting insulin
levels and insulin action as measured by the clamp technique [29]. However, these 2 methods
measure the insulin action at two different states; fasting insulin measures the basal insulin
levels at fasting state contrary to the clamp technique which is a stimulated state.
Accordingly, FI manly measures the hepatic insulin sensitivity (Liver mainly cause 20-30%
of glucose disposal) [29, 84]. The literature does not provide any evidence that FI can be used
to check the fed state and muscular insulin resistance.
More evidence is needed to conclude the specificity of each measure to explain their use. To
the current understanding, a high plasma insulin value in individuals with normal glucose
tolerance reflects insulin resistance, and high insulin levels presage the development of
diabetes.
Homeostasis model assessment (HOMA)
Just as measuring fasting insulin, the mathematical model of the normal physiological
dynamics of insulin and glucose produced; the homeostasis model assessment (HOMA) was
first developed in 1985 by Matthews et al. [85]. It is a method used to quantify insulin
resistance and beta-cell function from basal (fasting) glucose and insulin (or C-peptide)
concentrations. HOMA is a model of the relationship of glucose and insulin dynamics that
predicts fasting steady-state glucose and insulin concentrations for a wide range of possible
combinations of insulin resistance and β-cell function. The model has proved to be a robust
clinical and epidemiological tool for the assessment of insulin resistance, but as FI it does not
specifically show the muscle insulin resistance [81]. It should be recognized that HOMA is a
measure of basal insulin sensitivity and β-cell function and, in contrast to clamps, is not
intended to give information about the stimulated state [86].
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Following are the common parameters measured and their available desired targets for
glycemic control and insulin resistance [33]:
HbA1c < 6.5%
Fasting blood sugar < 5.5 mmol/l (< 100 mg/dl)
Two hours post meal blood sugar < 7.8 mmol/l (< 140 mg/dl)
Fasting Insulin level (micIU/ml)
Insulin Resistance (HOMA- IR)
2.4.3 Types of measures used to detect the effect of glycaemia in previous exercise
studies
The positive effects of exercise in glycemic control are well established. A review conducted
in 2017 by Grace et al. included most randomized controlled trials conducted to-date of
aerobic exercise training, in people with T2DM [87]. The interventions were both supervised
and unsupervised and ranged from 4-52 weeks duration. Resistance training studies were
excluded. Investigations of FBS, HbA1C%, Fasting Insulin and HOMA-IR were used to
assess glycemic effect.
Out of 27 studies 20, 18, and 8 and 7 papers provided data on HbA1C%, FBG, Fasting
Insulin and HOMA-IR, respectively. All studies showed significant improvement in
glycaemia from each glycemic assessment method, in exercise participants versus control.
The majority of the studies used HbA1C as the method of determining glycemic control and
assessment of IR was not evident in most studies.
The majority of the studies were from the European and White Caucasian origin, with only
7/27 from Asia (Korea-2, India-2, Thailand-1 and Iran-2) and 2 were from South Asia. The
studies from India had checked HbA1c only. The insulin resistance was not assessed in South
Asians with regard to exercise. This shows the importance of HbA1c in long-term glycemic
control as well as lack of data on effects of exercise in insulin resistance.
A meta-analysis conducted in 2014 by Schwingshacki et al. included only RCTs which
compared effects of different exercise modes with patients with T2DM [88]. Aerobic exercise
(AT), Resistance exercise (RT) and Combined training (CT) were used. The studies had
following criteria: (1) a randomized controlled design; (2) a minimum intervention period of
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8 weeks; (3) patients with type 2 diabetes; (4) patients’ age ≥ 19 years; (5) a comparison of
either AT vs. RT and/or CT vs. AT and/or CT vs. RT.
Out of the trials, 10 compared RT vs. AT, 9 compared CT vs. AT, and 5 compared CT vs.
RT. The majority of the trials used HbA1c as the mode of measuring the long-term glycemic
control and no studies showed the measurement of Fasting Insulin or HOMA-IR to detect
Insulin resistance. This points to the importance of using HbA1c as a main outcome measure
of chronic glucose control and supportive measures such as FBS, FI, and HOMA to give a
more descriptive output about the control of T2DM.
2.4.4 The independent effects of AT and RT in glycemic control - Effects on different
ethnicities
When considering exercise as a therapeutic mode for South Asians with T2DM; the current
evidence directs further exploration of benefits of customizing exercise recommendations. It
is important to examine the independent effects of the exercise modes in each ethnicity when
trying to customize exercise. When comparing AT with RT, the benefits of each of these
exercise modes on HbA1c is not described adequately [41]. Some studies suggest that AT is
more effective than RT in reducing HbA1c levels [89], especially in white Caucasians.
However, the evidence is not compelling enough to make conclusive clinical
recommendations due to the heterogeneity of the studies conducted to date [41].
A landmark study comparing AT, RT and CT groups (each group n=60) on effects HbA1c
was conducted by Sigal et al. in 2007 (Diabetes Aerobic and Resistance Exercise (DARE)
study) mainly with White Caucasians [90]. Church et al.(2010) conducted the Health Benefits
of Aerobic and Resistance Training in individuals with type 2 diabetes (HART-D) study with
Caucasians, African Americans and Hispanics [70]. Both studies reported that CE is superior
compared to the independent effects of each mode (AT/RT) which strengthen the present
combined exercise (CT) recommendations.
In the DARE study, the CT group had a larger reduction in HbA1c (−1.0%) compared with
the RT (−0.4%) and AT (−0.5%) groups. However, the dose of exercise was different. The
CT group performed both the aerobic and resistance training for 135 minutes a week for each
activity type, resulting in approximately 270 minutes per week of exercise. It is unclear
whether the additional benefit observed was due to the combination of RT and AT or to the
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extra volume of exercise. This is a question with significant clinical and public health
importance as to whether for a given amount of time, the combination of aerobic and
resistance exercise is better than either alone, which was not answered [70].
The HART-D study compared AT, RT and CT (each group n=72) controlling for exercise
dose (approximately 140 min per week). The absolute change in HbA1c in the CT vs. the
control group was −0.34%, RT was −0.2% and AT was −0.2%. The difference (HART-D vs.
DARE) in change in HbA1c in the CT groups (−0.3% vs −1.0%) might be explained by the
larger RT dose performed by DARE participants. The exercise doses were similar (according
to ACSM guidelines) in the 2 studies, in AT and RT groups. The differences in AT (−0.2 vs.
−0.5%) and in RT (−0.2 vs. −0.4%) was attributed to the differences in the study populations
(HART-D study populations had a higher prevalence of non-white participants than DARE
(47% vs. 8%), a longer duration of diabetes (7.1 vs. 5.4 years), inclusion of more women
(63% vs. 36%), and inclusion of the HART-D participants who were treated with insulin
without minimizing hypoglycemic medication change.
The outcome of these well-controlled studies justify that the physiological effects and
outcomes of exercise differ according to the ethnicity. Also especially during CT, glycemic
control can change according to the specific exercise dose (more RT dose in DARE study).
Relative evidence in South Asia is sparse regarding this subject even with millions of T2DM
patients diagnosed at present. Only two studies have investigated South Asians/Asian Indians
and examined the effects of exercise interventions with T2DM. Misra et al. in 2008
incorporated progressive RT for Indians with T2DM, and detected 0.5% reduction in HbA1c
values [55]. This study did not have a control group or an AT group to compare the effects.
Shenoy et al. in 2009 published the effects of a controlled study with RT, AT groups using a
methodology comparable with other studies conducted so far [91]. Reduction in HbA1c
levels of RT group (-1.8%) was superior to AT group (-1.3%) and even larger than the other
ethnicities. Both have attributed this better outcome in RT is due to relative high body
adiposity and less lean mass in Asian Indians compared to White Caucasians.
A systematic review conducted in 2013 that included 12 RCTS, compared effects of RT and
AT in HbA1c [41]. Three studies showed superior effect from RT compared to AT. The
study from India (Shenoy et al. 2009 ) and another study from Ng et al., (2010) investigating
Singaporeans of Asian origin ( AT/RT,-0.3% /-0.4%) showed a slightly superior effect from
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RT compared to AT [92]. Similar to South Asians, Singaporeans also have a higher
percentage of body fat for the same body mass index as Caucasians [93]. Cauza et al.,
studying Austrians also showed a superior effect from RT which was attributed to higher
baseline HbA1c of RT group compared to AT group (8.3% to 7.7%) [94].
Therefore, there is a need for further studies to identify the most effective exercise mode for
South Asians, a population known to have more visceral fat, less muscle mass and low
cardiovascular endurance and who appear to respond better to RT than AT. They might also
benefit from a more customized exercise recommendation.
The benefit of reducing glucose levels depend on the patient’s ability to get a sufficient
amount of exercise [4]. Many people with T2DM may have overweight/obesity, mobility
issues, visual defects, peripheral neuropathy, cardiovascular disease or unwillingness to
engage in a sufficient amount of aerobic exercise [41]. This will lead to difficulty in
achieving the required volume and intensity of AT to maximize health benefits [95]. In this
case, RT may be a feasible choice for patients who are unable or unwilling to adhere to
exercise that involves substantial amounts of energy expenditure from AT. However, RT will
involve some initial instruction and training which is not required as much for AT.
2.4.5 Previous studies: gaps in methodological design
Grace et al. [87] noted the space for improvement in the methodologies of the trials
conducted to-date. Considering the detailed methods, some aspects of the study designs were
conducted poorly on more than 50% studies. The method of randomization was only clearly
stated in 9/27 studies; group allocation was only concealed from assessors in 5 studies;
physical activity monitoring of controls was only performed in 1 study; exercise intensity was
periodically reviewed in only 5 studies; assessor blinding was only employed in 4 studies;
intention to treat analysis was only done in 3 studies. It is understood that conducting a RCT
will bring-in challenging issues of feasibility depending on the finances, human resource and
infrastructure availability. It is important to balance these challenges with minimizing the
errors and plan future trials adhering to scientific methodology which will enable the
outcomes to be compared across different trials and ethnicities.
In South Asia; conduct of interventional studies on exercise has only recently commenced.
Only two studies to date have investigated South Asians/Asian Indians and examined the
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effects of exercise interventions with T2DM. Misra et al. in 2008 incorporated progressive
RT for Indians with T2DM. This study did not have a control group or an AT group to
compare the effects. Shenoy et al. in 2009 published the effects of a controlled study with
RT, AT groups using a methodology comparable with other studies conducted so far. If
parallel conclusions are made with the rest of the studies conducted in other ethnicities, more
improvement should be done to the methodological designs.
2.4.6 New trends in exercise - the good, the bad and the unknown
Exercise non-responders and responders
Exercise benefits most individuals with T2DM without dispute; however, some people derive
significantly less metabolic benefit. Several studies have found that ~15–20% of individuals
fail to increase muscle mitochondrial density and improve their glucose homeostasis and
insulin sensitivity after supervised exercise interventions [96]. Notably, the term ‘non-
response to exercise’ or ‘exercise resistance’ is being used by authors to describe this
phenomenon. Currently, very little is known about the underlying mechanisms of “exercise
resistance”, substantial evidence suggests that this phenomenon is heritable [97]. It was
speculated that differences in muscle mitochondrial content and mitochondrial fuel oxidation
in response to training in different individuals might play a role in exercise non-response
[34]. Additionally, there is evidence that not only muscle, but also altered adipose tissue
metabolism can be a contributor and there is a need to clarify a possible pathogenic role of
inflammation and its mediators [98]. The involvement of the central nervous system [98] was
also discussed for further understanding of the exercise-brain-metabolism axis, which need
more human studies.
Oral hypoglycemic drugs and exercise
Oral hypoglycemic drugs are widely used among T2DM [99]. Metformin is the most widely
prescribed first-line oral anti-diabetic drug recommended by the American Diabetes
Association (ADA). It is estimated that there were over 42 million prescriptions for
metformin in the U.S. in 2009.
Reductions in HbA1c of 1% leads to a 40% lower risk of microvascular cardiovascular
complications [100]. Metformin monotherapy for more than 3 months is known to reduce
HbA1c by 1.1%, and metformin in combination with other oral hypoglycaemic drugs
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(sulfonylureas and dipeptidyl-peptidase 4 (DPP-4) inhibitors) by 0.8-0.9% [101]. Evidence
suggests that sulfonylurea monotherapy may be more effective in the short term, but lose
effectiveness after couple of months [102]; whereas dipeptidyl-peptidase 4 (DPP-4) inhibitors
may be the least effective [100]. It is unknown whether these effects reflect what happens in
the clinically relevant dual- and triple-therapy settings. The drug therapy in higher baseline
HbA1c is associated with greater absolute response to treatment, with a 1% increase in
baseline HbA1c causing nearly 0.5% greater reduction.
The effects of Metformin have been studied widely compared to other drugs. There is a
popular belief that combination of exercise and Metformin offers additive benefits on
glycemic control. Despite the vast literature examining the effects of Metformin or exercise
separately, surprisingly few studies have examined how they affect each other, or if their
combination offers additive benefits [99]. There is some evidence suggesting that the benefits
of exercise and Metformin are not additive. In addition, Metformin has been recently
suggested to attenuate the insulin-sensitizing effect of exercise [103].
Metformin exerts action via inhibition of mitochondrial glycerophosphate dehydrogenase and
ATP synthase, thereby increasing [AMP]/[ATP] ratio, activating AMPK and increasing
insulin sensitivity [104]. Aerobic training acts in part through the same pathway; suggesting
that these two stimuli could act synergistically. A recent RCT demonstrated that compared
with controls, AT led to a significant reduction in HbA1c in Metformin users (-0.57%) but
not in untreated individuals (-0.17%) [105]. Importantly, this effect was only observed with
AT and AT + RT. The RT only group did not achieve significant reductions in HbA1c. The
effect of RT on individuals with T2DM, currently taking Metformin and other anti-diabetic
drugs remains to be determined.
It is an important consideration for current diabetes treatment guidelines is the use of
Metformin in combination with exercise training as the question of synergism vs. antagonism
remains unanswered.
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2.5 Exercise, Body Composition and Adiposity
Apart from glycemic control (HbA1c), maintaining normal adiposity is a concern in
management of T2DM. Central obesity with high visceral adiposity detected in South Asians
causes low-grade systemic inflammation by inflammatory mediators. These mediators which
are derived from adipose tissue (adipokines, adiponectin and tumor necrosis factor-α) [7, 43,
48] have emerged as risk factors for development of IR, T2DM, and CVD.
2.5.1 Measurement of adiposity
The gold standard for body composition measurement is direct cadaver analysis, where no in-
vivo technique considered to meet the highest criteria of accuracy [106]. All other techniques
do not measure body composition directly, but rather predict it from measurements of other
body properties. From the several techniques available: a single technique is unlikely to be
optimal in all circumstances. Thus, all techniques incur methodological error when collecting
raw data, and error in the assumptions by which raw data are converted to final values. In
short, all techniques have strengths and weaknesses [106].
Simpler measurement approaches requiring minimal equipment include waist circumference
(WC), body mass index (BMI) and skinfold thickness. Waist circumference (WC) provides a
simple measure of central fatness, which may be more predictive of adverse outcomes such
as lipid profile or insulin resistance than total fat. WC with measures of abdominal fatness
obtained from magnetic resonance imaging (MRI) have shown consistently high correlations
[107]. In adults, waist–hip ratio is independently associated with morbidity [108]. But studies
reporting the association between waist: hip ratio and abdominal fat are inconsistent, and
some find no significant relation [107, 109].
Predictive techniques use both skinfold thickness and bioelectric impedance measurements to
assess body composition. Traditionally, skinfold thickness measurements have been used to
rank individuals in terms of relative “fatness” or to assess the size of specific subcutaneous
fat depots. The best use of skinfold thickness data is as raw values, where they act as reliable
indices of regional fatness [110].
Bioelectric impedance analysis (BIA) measures impedance of the body to a small electric
current [111]. Dual energy x- ray absorptiometry (DXA) measure bone mineral mass, and
body fat mass which is calculated from the differential absorption of X-rays of two different
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energies [110]. Densitometry distinguishes Fat mass (FM) and fat free mass (FFM) assuming
specific densities of these two tissues and therefore requires measurement of total body
density (body mass/body volume) [112]. Traditionally, body volume was measured by
hydrodensitometry. A new alternative is air displacement plethysmography (BODPOD)
[113].
Isotope dilution (hydrometry) / Deuterium dilution can be used to measure total body water
(TBW), allowing estimation of FFM. A dose of water labelled with deuterium is given and,
following equilibration, enrichment of the body water pool measured using samples of either
saliva, urine, or blood [114]. Magnetic resonance imaging (MRI) and Computer
Thermography (CT) are imaging techniques that estimate the volume rather than the mass of
adipose tissue. By analyzing the absorption and emission of energy these two imaging
techniques are now considered to be the most accurate methods for measuring tissue, organ,
and whole-body fat mass, as well as lean muscle mass and bone mass [110].
2.5.2 Selecting a measurement technique for primary outcome measure: adiposity
The total %body fat , lean muscle mass and regional % body fat are important to interpret
more descriptive effects of exercise on adiposity of Sri Lankan adults with T2DM.
Skinfold measurements and WC provide a simple, easy, and quick yet highly informative
assessment of fatness. Whole body data may appear optimal, but in practice regional data
may be more informative about clinical condition, as well as more accurate. In South Asians
one main concern is central adiposity, so monitoring of WC may provide a better indication
of health risk, and response to treatment, than whole body fatness.
Though BIA has potential utility in measuring regional body composition, predictive error in
individuals is high, even when using population specific equations. If used to monitor
individuals over time, it can indicate the direction, but not the magnitude, of changes in lean
mass. However, such data are difficult to interpret in the absence of reference data.
Owing to its good precision, availability, and low radiation dose, dual-energy X-ray
absorptiometry (DXA) is a convenient and useful. DXA allows both regional and total body
composition estimates, characterizing fat mass (FM) and dividing fat-free mass (FFM) into
two components, lean soft tissue (LST) and bone mineral content (BMC). DXA measurement
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is minimally influenced by fluctuations in the water component [110]. It is a relatively
accurate technique for quantifying limb lean mass but has poor accuracy for trunk fatness
which gives information in central adiposity. The application of WC and skinfold thickness
measures to DXA may improve the data on central adiposity.
The multicomponent models which combines couple of measurement methods (Eg. Total
Body Water (TBW) by deuterium dilution, Body Mass, Body Volume by air displacement
(BOD POD) or Underwater Weighing (UWW), Bone Mineral Content by Dual-Energy X-
Ray Absorptiometry) are considered sufficiently accurate to act as reference or criterion
methods. CT and MRI scans are accurate and allow for measurement of specific body fat
compartments, such as abdominal fat and subcutaneous fat. They are expensive and
limitation of CT scans is high amounts of ionizing radiation. Even Multicomponent models
and scans are ideal for detailed analyses but remain unfeasible in most contexts.
The value of any approach is greatly enhanced by the availability of reference data. The
acquisition of such data is a current priority, being addressed by several research groups.
2.5.3 Different reference values for South Asians on adiposity measures
Obesity related co-morbidities at lower levels of body mass index (BMI) and waist
circumference (WC), have been detected in South Asians due to the higher body fat at a
given value of BMI than white Caucasians [115]. It has been debated whether BMI cut-offs
should be lower for Asian populations as compared to the available international guidelines
(25.0 - 29.0 kg/m2 as overweight, 30 -34.9 kg/m2 as obesity) [1]. In 2004, a WHO expert
Consultative Committee suggested BMI cut-offs as ≥23–24.9 kg/m2 and ≥25 kg/m2 for
overweight and obesity, respectively [116]. Though this issue has been intensively debated,
the WHO group discussed that no firm action should be taken internationally, and left the
decision for guidelines for BMI to the governments of respective Asian countries at that time.
Subsequently, a Consensus Group from India formulated revised guidelines for BMI for
Asian Indians [117]. However, BMI has important limitations, though it is positively
correlated with adiposity, it neither discriminates fat from lean mass nor fully reflects the
distribution of body fat.
The selection of international obesity cutoff points of WC (for men, ≥ 94 cm, and women, ≥
80 cm) are based on data derived from white Caucasians [118]. For Asians the WHO Expert
Committee on Obesity in Asian and Pacific populations suggested revised cutoff points for
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waist circumference: 90 cm for men and 80 cm for women [116]. Later, an Indian expert
group proposed the following action levels for adult Asian Indians; men, ≥78 cm, women,
≥72 cm [119]. Most of the researchers have felt a need to revise international guidelines for
South Asians.
Reference values for %body fat have not been published internationally. WHO Expert
Committee (2004) stated without reference that “…overweight (≥25 kg/m2) corresponded to
31-39% (mean 35%) body fat in females and 18-27% (mean 22%) body fat in males [120]. If
these criteria for the percentage body fat for overweight and obesity are applied to the Asian
populations, the corresponding BMIs can be calculated with country-specific equations.” But
for these data original scientific validation has not been published. To date, there is no
validated threshold of body fatness for defining obesity.
2.5.4. Exercise and relative benefits of AT and RT in adiposity
The most effective method of exercise (AT, RT, CT) of reduction in visceral adiposity, while
maintaining muscle mass, is still unclear [121].
Based on the current understanding, to lose weight and maintain it, a negative energy balance
must be attained and such balance must be maintained [122]. Negative energy balance refers
to less amount of energy intake compared to energy expenditure. Energy intake consists of all
ingested foods and beverages with an energy value; which is influenced by environmental,
behavioral, biological, and genetic influences. Energy expenditure consists of resting
metabolic rate (RMR), the thermic effect of foods (TEF), spontaneous physical activity
(SPA), and exercise [123].
Reduction in body weight and BMI seem to be more via AT compared to RT. The WC is
known to reduce mainly via RT. The decrease in fat, without decrease in body mass probably
reflects a significant increase in fat free mass or muscle mass which is mainly seen in RT.
Either RT/AT can develop muscle, which is heavier than adipose tissue [68]. But the effect of
increasing muscle is more in RT. In the early stages of an exercise program, an increase in
lean mass might obscure any weight loss due to adipose tissue loss. Over time lean mass does
not keep increasing to the same extent as adipose tissue loss. Eventually weight loss occurs
due to loss of adipose tissue. The duration of a majority of the current trials was too short to
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elicit detectable changes in body mass. Interventions for sustained weight change require
durations of up to one year [68].
It is been postulated that the impact of exercise training on insulin sensitivity is mediated by
diminished body weight and/or adiposity [124]. In other words, exercise training without
weight loss is not associated with improvements in insulin action when assessments are made
96 h post exercise. In the process of different exercise methods and their relative duration of
achieving fat loss might determine the insulin sensitivity and glucose control. On the other
hand exercise training without weight loss may enhance insulin-stimulated glucose disposal
but insulin resistance commonly returns to near baseline levels after cessation of the exercise
suggesting that activity without weight loss primarily affects variations in glycogen stores
and glycogen synthase activity [124-126]. The evaluation of regional fat distribution
differentiation is important to evaluate since these areas of fat deposition may influence
insulin resistance differently and exercise training may have a variable influence on specific
fat depots [127].
In the current context, it can be hypothesized that change in increase in muscle mass would
be more significant in South Asians who already have baseline less lean mass and high body
fat. The change in the parameters can be expected even in a shorter duration of exercise
which would give additional benefits. The change in adiposity, is not studied/documented in
South Asians/Sri Lankans to date.
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2.6 Effects of exercise in metabolic parameters
2.6.1 Blood Lipid profile
The ‘lipid profile’ describes the lipids in the blood; namely low-density lipoprotein (LDL)
cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides (TG) and the most
commonly used measure of cholesterol ‘total cholesterol (TC)’ [128]. TC includes LDL
cholesterol and HDL cholesterol. High LDLs indicate surplus lipids in the blood, which
increase the risk of cardiovascular complications. In contrast, high levels of HDL are an
indicator of a healthy cardiovascular system as HDLs transport lipids back to the liver for
recycling and disposal [129]. Plasma triglycerides which are derived from dietary fats are
positively and independently associated with cardiovascular disease [130]. It should be noted
that given the different effects of LDL and HDL on health, total cholesterol can be a
misleading metric [128]. Most of the time people with metabolic syndrome and T2DM have
an abnormal lipid profile as a positive association [131]. Insulin resistance, which is central
to T2DM, leads to high levels of very low-density lipoprotein (VLDL), which contain a high
concentration of TGs, resulting in high serum triglyceride levels and low serum HDL levels
[132]. Also, abnormal blood lipid profile is positively correlated with intra-abdominal fat
/visceral adiposity [131].
Statin drug therapy has been emphasized in the current US and European guidelines as the
primary treatment for LDL reduction, because of strong evidence of safety and efficacy
[133]. Limitations of statins are that many people cannot tolerate them and they are
contraindicated in pregnancy. Several novel methods have immerged in reducing LDL in
active studies, which are still not freely available and are expensive. Research has been
conducted to increase HDL concentrations directly and via recombinant technology, still
without positive outcomes [134]. For the reduction of TG, more advice comes from changes
in lifestyle, such as sugar and the Mediterranean diet and with drugs are also effective, such
as fibrates, fish oil and niacin [135].
Exercise is known to improve the blood lipid profile. Mechanisms may involve the increased
activity of enzyme lipoprotein lipase (LPL) which is responsible for chylomicron, VLDL and
TG hydrolysis [136]. LPL activation could last for 24 hours after only a 1 hour moderate
intensity exercise session [137]. Also exercise leads increased TG consumed by muscle tissue
and increases LPL which results in more TG hydrolysis [133, 137]. Upregulation of increased
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receptor expression in macrophages results more cholesterol transported to the liver via HDL
[138].
Despite the understandings of above mechanisms, the objective outcomes of the lipid profile
as an effect of exercise are not conclusively determined by research. Many studies have been
criticized for methodological flaws or design limitations that make the results somewhat
questionable. Due to limitations of other available treatment options, the importance of
exercise in the management of hyperlipidemia still persists.
A Cochrane review in 2006 stated that exercise decreased plasma TG significantly compared
to non-exercise [139]; where a systematic review by Mann et al. in 2014 suggested most
likely improvement to be increase in HDLs with a linear dose–response relationship [128].
Now in general, it is synthesized that regular physical activity has been shown to increase
HDLs while maintaining, or offsetting increases in LDLs and TGs [128]. When studying
different exercise modes, aerobic training on lipids have been studied more compared to
resistance training. Several meta-analyses and a latest review in 2017 reported that HDL
levels are more sensitive to AT than both LDL and TG [133]. Another review [140] in 2013
concluded that RT had superior effects compared to AT in reducing TGs and TC. A recent
larger systematic review which pooled studies comparing different training modalities (AT,
RT and CT) concluded no significant differences were observed for TC, LDL, HDL, and TG.
The common limitation still persists; due to the different methodologies in the trials, authors
have stated substantial statistical heterogeneity in these values and interpretations.
South Asian data are very limited, where randomized controlled studies are not published.
The only studies in India, Misra [55] who incorporated RT to T2DM identified reductions in
TC and TG in a cohort study, which was later confirmed by a more controlled study by
Shenoy and the colleagues [141].
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2.6.2 DM and Nonalcoholic fatty liver disease (NAFLD) – Liver Enzymes and Exercise
The liver is an important organ in the body which is essential in glucose metabolism,
detoxifying various harmful substances, assisting excretion of waste products and production
of blood clotting factors, bile and other important proteins like immune factors. Insulin
resistance and inflammatory mediators (adipokines, adiponectin and tumor necrosis factor-α)
which is the result of adiposity [7] are known to be directly toxic to hepatocytes in the liver
[43]. They can cause damage to hepatocytes leading to hepatic fat accumulation and chronic
hepatic injury. During the damage to these cells, the enzymes stored inside them, such as
alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are released to the
blood stream [7]. A normal ALT should be <29–33 IU/L in males and 19–25 IU/L in females
and normal serum AST is 0 to 35 IU/L [142]. ALT is a more specific marker of hepatic injury
than AST.
Increments in AST/ALT are frequently found in T2DM patients which is also predicted as a
risk factor for its development [143] when included along with the traditional risk factors.
The most common cause of elevated liver enzymes in DM is nonalcoholic fatty liver disease
(NAFLD) [7]. This disease happens due to increase fat accumulation in the liver which is
associated with hepatic IR [144]. Insulin resistance cause reduction in insulin-stimulated
hepatic glucose uptake and decreased insulin suppression of hepatic glucose production,
which both contribute to increased plasma glucose levels [145]. NAFLD leads to Non-
alcoholic steatohepatitis (NASH) and liver failure [146] which can lead to death.
In addition to the magnitude of AST/ ALT elevations, the ratio of AST to ALT is useful in
determining the etiology of liver damage. Typically for NAFLD, ALT levels are >AST levels
[142]. A study which examined a general Korean population stated elevated levels of ALT
were independently associated with T2DM [48]. A high incidence of elevated ALT in
patients with newly diagnosed T2DM, suggesting that the onset of the liver abnormalities
associated with dysglycemia may precede the diagnosis of T2DM itself [147]. These
abnormal ALT levels are associated with features of the metabolic syndrome, but not
glycemic control.
Physical exercise can result in transient elevations of liver function tests [148]. There is no
consensus in the literature on which forms of exercise may cause changes in liver function
tests and to what extent [148]. Liver function tests are significantly increased for at least 7
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days after resistance training and also lesser extent for aerobic training. Research has
progressed for effects of energy expenditure benefits of exercise with regard to liver health.
In 2012, Thoma et al. who reviewed the effects of diet and exercise on liver function,
concluded that dietary-induced weight loss may offer greater liver health benefits than
exercise [149]. Another systematic review, of randomized and non-randomized controlled
studies in obese and NAFLD populations, by Keating et al. failed to show changes in liver
enzymes with exercise training [150]. The review was well powered; however, several
confounding variables in the included studies may have prevented the isolated effects of
exercise to be examined. The exercise training programs varied greatly between studies with
respect to exercise intensity, duration, frequency and modality (e.g., aerobic vs. resistance
training). The authors concluded that liver enzymes have limited sensitivity in detecting early
liver disease and liver enzymes are, at best, a blunt tool for assessing change in liver function
after exercise training. But being a widely used test its importance and applications should be
further explored.
Bacchi et al. in 2013 demonstrated RT and AT are equally effective in reducing hepatic fat
content among type 2 diabetic patients with NAFLD [143]. Despite all the evidence; exercise
is now incorporated to the management of early stage NAFLD where once traditional diet
only management was used [151].
The effect of exercise on visceral adiposity and changes in liver enzymes (AST/ALT) is not
studied in South Asians who have a relatively higher amount of body fat [5], and higher
visceral adiposity [152].
2.6.3 Inflammatory biomarkers (highly sensitive CRP- hs CRP) and Exercise
Cardiovascular diseases (CVD) are the most prevalent cause of death in patients with T2DM,
which includes myocardial infarction, ischemic stroke and peripheral arterial obstructive
diseases. Vascular atherosclerosis is the main cause for CVD development and systemic
inflammatory activity has turned out to play a key pathogenic role in vascular atherosclerosis,
insulin resistance, and T2DM [153]. Inflammatory biomarkers have become valuable tools
for risk evaluation. Among them, the best evidence to date supports the use of highly-
sensitive C-reactive protein (hs-CRP) to monitor insulin resistance and cardiovascular risk
[154]. In addition, the data suggests that hs-CRP may also participate directly in the process
of atherogenesis [155].
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C-reactive protein is a special type of acute phase protein produced by the liver during
episodes of acute inflammation. CRP is traditionally measured down to concentrations of 3-5
mg/L, whereas hs-CRP measures down to levels around 0.3 mg/L. This improved sensitivity
allows hs-CRP to be used to detect low-grade systemic inflammation. Based on multiple
epidemiological and intervention studies levels of hs-CRP is categorized for predicting future
cardiovascular risk (hs-CRP < 1 mg/L = low risk, 1–3 mg/L = inter-mediate risk, 3–10 mg/L
= high risk, > 10 mg/L = unspecific elevation) [155].
Regular exercise is reported to reduce the general inflammatory status. Kamal et.al
examining obese children found reduced CRP levels after a 12 weeks exercise program
[156], whereas Donges et al. examining 102 sedentary adults demonstrated that RT over a
period of 10 weeks significantly reduced the CRP concentrations by 33% [157]. The anti-
inflammatory effects of regular exercise are proposed to be caused by a reduction in visceral
fat and/or by induction of anti-inflammatory cytokines or by inducing a pronounced
hypoglycemic effect. A recent systematic review of RCTs [158] which compared AT with a
Control group from Greece (n=4), United States (2), New Zealand (1), Brazil (1), Australia
(1), Iran (1) and Germany (1) reported contradictory results about the effectiveness of
training to reduce plasma CRP levels. While Kadaglou et al. and Oberbach et al., reported a
reduction in the plasma CRP levels of trained individuals, three other studies found no
significant difference. The studies used similar time of session training (30–60 minutes), but
differed in duration of patient follow-up, weekly workout frequency, and training intensity.
Kadaglou et al. who further studied effects of RT, reported AT predominantly contributed to
hs-CRP reduction, but RT conferred non-significant effects [159].
Even some results support the anti-inflammatory effect of aerobic training; it require further
verification. No studies to date have examined this parameter in South Asians.
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2.7 T2DM and Physical fitness
Cardiovascular endurance, muscle strength and endurance, flexibility, body composition are
components of health-related physical fitness [50]. Physical fitness is mainly determined by
the volume (intensity and duration) of physical activity/exercise, and increases with training.
Mainly aerobic training enhances cardiorespiratory fitness and resistance training augments
muscular fitness [160, 161]. Both components of physical fitness have been shown to be
inversely related to all-cause mortality in healthy people [162]. For subjects with T2DM, an
association with all-cause and CVD mortality has been shown for mainly cardiovascular or
aerobic fitness/endurance. Current evidence relates the improvement of muscle mass,
endurance and strength with improvement in glycemic control in T2DM. The relation of
physical fitness with mortality is described independent of reduction in BMI.
Maximum oxygen uptake (VO2max) is considered the best indicator of cardiovascular
endurance which is an outcome of integration of the circulatory, respiratory, and muscular
systems to supply oxygen to the working tissue during physical activity. However, because of
the strenuous effort required by the participant; measuring VO2max is often neither convenient
nor safe for individuals with comorbidities, old age and those who are deconditioned. High
equipment costs, adequate facilities and appropriately qualified personnel also may limit the
opportunities to measure VO2max. An alternative to the measurement of maximal oxygen
uptake is prediction of oxygen carrying capacity via submaximal functional tests. Two such
functional tests that are practicable in many settings are the Six-Minute Walk Test (6MWT)
advocated by the American Thoracic Society [163] and the YMCA Three-Minute Step Test
(TMST) [164] included in the American College of Sports Medicine’s Guidelines for
Exercise Testing and Prescription.
2.7.1 Six Minute Walk Test (6MWT)
The reliability, validity, and responsiveness of the 6MWT are well established. The test
requires participants to walk in a 20 m track/course as far as possible over 6 minutes. At the
end; the distance, perceived rate of exertion and heart rate are measured [163]. The change in
the distance walked and the peak heart rate achieved in the 6MWT can be used to evaluate
the efficacy of an exercise training program or to trace the natural history of change in
exercise capacity over time. Commonly the test is used to determine exercise capacity in
patients with chronic heart failure or pulmonary disease. In addition this test can be a useful
addition to the test battery of CV endurance when testing unconditioned participants across
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broad age spectrum who will not be able to complete progressive submaximal exercise
testing.
2.7.2 Step test (3MST)
The reliability and validity of step tests has also been demonstrated. Among a number of step
tests used in research studies, the YMCA 3-Minute Step Test (3MST) is one of the most
widely used. The participant steps up and down on to a bench with a fixed height and
stepping sequence for 3 minutes, where heart rate is monitored and documented at end of
each minute and one minute post-test (4th minute).While the 3MST requires less space, it
tends to be more physically demanding.
The 6MWT involves little work against gravity and performance is determined by the self-
selected effort expended. As running is not permitted, even prolonged walking at a maximum
speed is demanding. The 3MST, on the other hand, involves greater work against gravity and
a fixed dose of effort which is therefore more affected by body mass and stature.
2.7.3 Exercise ECG/Electrocardiogram
Before starting progressive exercise training or exercise testing, an unconditioned sedentary
individual should complete a symptom-limited maximal ECG exercise test, as widely used
and well-established for the detection of coronary artery disease. The exercise ECG is
conducted under the guidance of consultant cardiologists and trained cardiographers in an
environment where resuscitation facilities are available. Such testing can also be expensive in
a low resource setting like Sri Lanka; however for safety reasons, screening participants with
risk factors is very important. Risk factors include the following: men >40 years old or
women > 50 years old (or postmenopausal) with 1 or more independent coronary risk factors
such as: hypercholesterolemia or dyslipidemia (total cholesterol >200 mg/dL; elevated low-
density lipoprotein [LDL] cholesterol [>130 mg/dL]; low high-density lipoprotein [HDL]
cholesterol [<35 mg/dL for men; <45 mg/dL for women]); systemic hypertension (systolic
blood pressure >140 mm Hg or diastolic pressure >90 mm Hg); current or recent cigarette
smoking; diabetes mellitus (fasting plasma glucose ≥126 mg/dL or treatment with insulin or
oral hypoglycemics); or history of myocardial infarction or sudden cardiac death in a first-
degree relative <60 years old. Interpretation of the test includes exercise capacity, as well as
clinical, hemodynamic, and electrocardiographic responses. An important ECG finding
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includes >1 mm (0.10 mV) of horizontal or down sloping ST-segment depression for >80 ms
during and/or in the first minutes of the recovery period [165].
In addition to risk assessment, the Exercise ECG provides an estimate direction of
cardiovascular endurance, electrocardiographic changes of the heart, blood pressure and heart
rate changes to progressive exercise.
2.7.4 Muscular Strength - One Repetition Maximum/1RM
Standard measures to determine muscular strength include a 1RM/one repetition maximum or
maximum amount of force generated in one maximal contraction. “Repetition maximum” is
the maximum amount of weight that can be lifted in a defined number of repetitions [166].
For example, 10RM would be maximum amount of weight that can be lifted 10 times
maintaining the correct posture and technique. 1RM is the maximum amount of weight lifted
with maximum effort in a single repetition. More precise isokinetic dynamometry can be
used to determine muscular strength however one needs expensive equipment.
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2.8 Exercise, liking and wanting for food
It is well known that dietary intake, both energy and macronutrient intakes, have a strong
influence on obesity and chronic diseases, especially T2DM.
Challenges to accurately measure of energy intake
The measurement of dietary intake is associated with many challenges; practical- and
validity-related [167]. There is a diverse range of methods available, mainly relying on self-
report, hence attract a series of issues relating to misreporting [168].Therefore, self-report of
food intake is prone to under-reporting , and misreporting.
Food Preference
One of the strongest predictors of dietary intake is ‘food preference’; as hedonic processes
influence food intake [169]. The control of food preference is documented as an important
factor in the management of T2DM [23].
Energy intake is regulated by multiple feedback processes and these constitute three
hierarchical control systems; homeostatic, hedonic, and cognitive, involving a complex
interaction amongst them. Homeostatic food intake is regulated through complex feeding
circuits in the brainstem and various hypothalamic nuclei focused on the balance of energy
intake and expenditure. The cognitive mechanisms linked to eating behavior comprise of self-
regulation, social feedback, and environmental feedback [170]. The new understandings of
activation of the brain’s reward system can lead to food intake well beyond bodily
homeostatic needs via “hedonic hunger” that operates even without the presence of physical
hunger from acute energy needs. This system operates through the mesolimbic system and
has a neurobiological basis in parallel with the homeostatic feedback system.
The hedonic pleasure of food can be seen as an interaction of' ‘liking’ and ‘wanting’.
Advances in neurobiology have supported the concepts of liking and wanting as modular
components of the reward system which can be seen as a major force in guiding human
eating behavior. Liking and wanting have been proposed as core processes with implicit and
explicit components. Explicit liking (acutely perceived hedonic reaction) can be associated
with explicit wanting (subjective desire for a perceived goal) and implicit wanting (incentive
salience attribution). Implicit liking (unconscious affect) may also influence implicit wanting
to influence food intake behavior without the subjective awareness of either process [171].
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Exercise could influence food intake by its rewarding potential and via an association with
increased energy expenditure. It has been hypothesized that exercise may act as a buffer for
reward driven eating, however it is also possible that exercise has a sensitizing action that
enhances food reward. A review by King et al.(2013) reported that there is no automatic
increase in food intake in response to acute exercise and that the response to repeated
exercise is variable with involvement of various behavioral, physiological, and psychological
processes potentially mediating changes in eating behavior with exercise [172]. Differences
in the impact of exercise on food reward explains some inter-individual variability in
compensatory eating after exercise.
There is evidence that some individuals adopt compensatory behaviors, i.e. increased energy
intake and/or reduced activity after exercise energy expenditure. Individuals who are more
susceptible to exercise-induced compensation could be characterized by an enhanced hunger
(homeostatic processes) or increased liking and wanting to food (hedonic processes), or both.
One of the key problems with studies assessing the efficacy of exercise as a method of weight
management and obesity is that individual variability in response is overlooked.
Understanding and characterizing variability will help tailor weight loss strategies to suit
individuals. It is a challenge for clinicians to identify which individuals are susceptible to
such behaviours, and to develop strategies to minimize or maximize their impact.
Finlayson et al. investigated a sample of young healthy women on acute hedonic response to
aerobic exercise had a sub set of compensators who ate more after the exercise bout [173],
and were characterized by enhanced implicit wanting for the food stimuli. Therefore, implicit
processes rather than hunger or explicit liking for a range of food can be associated with
compensatory feeding behavior. In some individuals it may play a role in the failure of
exercise, to facilitate weight loss in obese or glycemic control in T2DM. Identifying these
behaviors in advance may provide an opportunity to help explain why exercise is not
effective for everyone.
In the background of limited evidence in this area, Finlayson et al. further studied the acute
response to exercise conducted in two groups of overweight people who underwent 12 week
supervised aerobic exercise (AT) program. First group (group X) of participants displayed a
smaller reduction in body fat mass as response to exercise in comparison to the second group
(group Y) which showed significant reduction in body fat mass. Group X compared to group
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Y showed an immediate post-exercise increase in preference for food (specifically for high-
fat sweet food) after an acute bout of exercise. People who did not respond to the AT
program (group X-who had less reduction of body fat) had increased preference for high-fat
sweet food after an acute bout of exercise indicating that food preference is associated with
the response to exercise. The acute exercise session was a moderate intensity (70% heart rate
max) submaximal exercise conducted on a stationary exercise bike.
Martins et al. (2015) evaluated the role of exercise intensity on acute hedonic response during
acute bouts of aerobic exercise in overweight/obese individuals comparing high-intensity
intermittent cycling and moderate-intensity continuous cycling. The study found no
difference in liking, implicit wanting or relative preference for high fat food relative to low
fat food. These findings suggest that the overall mean pattern of food reward was stable.
Current studies have not specifically investigated resistance exercise (RT) into exercise
interventions which would have compared the effects of different mode of exercises on food
preference.
As acute hedonic response to aerobic exercise has shown the possible reasons for post
exercise eating behavior, similarly the chronic response to exercise will also be important to
understand the sustained effect of exercise on liking and wanting or vice versa. Horner et al.
studied hedonic response during fasting and fed state of active and inactive men [174].
Participants were categorized as inactive (undertaking ≤ 1 structured exercise session per
week and not engaged in strenuous work) or active (undertaking ≥ 4 structured exercise
sessions per week) based on their self-reported physical activity over the previous 6 months.
Active men had a greater increase in explicit liking and implicit wanting for non-sweet foods
in the fed state after breakfast compared to inactive men. Elevated ‘liking’ and ‘wanting’ for
energy dense foods are considered psychological markers in individuals who are susceptible
to overconsumption. However, this study showed the ‘active’ has less susceptibility for liking
for sweet food which is a clinically important for the management of T2DM.
Medication, exercise and diet are prescribed simultaneously to people with T2DM. Being a
chronic disease, all these factors need to be addressed to optimize the management outcome.
It will be important see whether exercise (and which type: aerobic or resistance) will be more
effective in controlling/not controlling the long-term calorie intake. Also, knowledge of
hedonic response to common types of food (high/low fat or sweet/non sweet) by an
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individual or the community will enable the clinician to plan the management process well in
advance.
2.8.1 Cultural differences in habitual diets: appetite regulation and food preferences
The predominant macronutrient in the Sri Lankan diet is carbohydrate, via rice (a low fat
non-sweet food). Recently it was identified that Sri Lankans consume much higher portions
of rice than the recommendations and only 3% -5 % of adults consume the recommended 5
portions of fruits and vegetables per day. In contrast to western countries and some Asian
countries, Sri Lankans consume proportionally more carbohydrates (>71% of energy), less fat
(<19% of energy) and proteins (<11%) [175]. The total daily intake of protein in Sri Lankan
adults is almost half that of the US adults and plant sources (rice and pulses) are the main
contributors of protein [176]. These factors are contributing to the excessive calorie intake
which is leading to T2DM and obesity. It is interesting to know how liking and wanting to
rice and other local food will increase/decrease after exercise. This has an important practical
implication.
Evidence is sparse in the literature which investigated chronic effects of RT and AT exercise
on preference /hedonic response to a particular type of food (Fat: high/low, Sweet, Savory).
Further, liking and wanting for food has not been investigated in Sri Lanka or in South Asia.
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2.9 Exercise on Quality of Life (QoL)
Much of the existing data on the effects of exercise on T2DM, place an emphasis on the
physiological and metabolic outcomes [177]. T2DM is associated with emotional or
psychological problems and a higher prevalence of depression is observed compared to that
of non-diabetics [177, 178]. Interest in the quality of life (QoL) of T2DM patients has been
growing as comorbidities and complications place potential strains on physical and emotional
wellbeing [178].
Studies in Western populations have shown that individuals with diabetes have a poor quality
of life compared with age-matched patients without diabetes. A similar trend was seen in a
study conducted in the Malaysian population by Kamarul et al. (2010) [179]. Additionally
they found that diabetic patients with poor glycemic control (HbA1c >7.5%) had lower QoL
scores than those with tight glycemic control (HbA1c <7.5%) [178].
Regular physical activity and exercise have been shown to result in improved QoL [180].
Martin et al. (2009) in a 6 month exercise intervention of previously sedentary, overweight or
obese, postmenopausal US women showed a higher exercise dose lead to greater
improvements in mental and physical health [181]. A growing collection of randomized
controlled studies have also looked at the effects of aerobic, resistance and combined exercise
training on QoL of T2DM patients. These studies have produced a variety of results, with
many showing improvements in the various aspects of QoL. A study by Reid et al. (2010),
following a 22-week exercise regime found that resistance training led to significant
improvements in physical health compared to aerobic, combined and control groups [178].
In 2011, the Italian Diabetes and Exercise Study published data on QoL, displaying that a
supervised combined training program leads to improvements in physical and emotional
wellbeing [182]. A systematic review of 16 randomized controlled studies in 2013 by Van
der Heijden et al. reported mixed results with resistance and combined training, and almost
no improvements with aerobic training [177].
Existing data concerning the effects of aerobic or resistance exercise alone on QoL in
participants with T2DM, are mostly inconclusive, with many studies showing improvements
in different scales of QoL yet most observations are not statistically significant or
conflicting. Furthermore, a majority of the data on exercise and QoL are gathered from
Caucasian populations whom have different sociocultural backgrounds compared to South
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Asians. The study of patients’ QoL is an emerging field in the South Asian region, and data
on QoL of diabetic patients is very limited [178]. Moreover, no investigations to date have
been conducted in South Asia to evaluate the effects of exercise on QoL in T2DM patients.
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2.10 Compliance/adherence to exercise and behavior change
Exercise training is integral in the prevention and management of T2DM and other chronic
lifestyle-related diseases [183, 184]. However, despite a strong evidence base, adoption of
appropriate lifestyle practices and, in particular, failure to adhere to physical activity and
exercise in the long-term is a challenging problem for health professionals and staff working
in the health and fitness industry [22, 185]. There is a common tendency for non-adherence to
exercise programs and many individuals returning to their former lower levels of physical
activity after discharge from a rehabilitation program [184]. The strategies to maximise
adherence, starting from the commencement of an exercise program, are fundamental to the
longer-term success of exercise interventions [184].
Qualitative studies can provide in-depth insight into an individuals’ experiences and
perceptions of the motives and barriers for participation in exercise and physical activity
[186]. It is recognized that such investigative methods are increasingly important in
developing the evidence base. If the studies are designed to elicit inductive themes (which are
based on empirical observations) they allow for theory to emerge from the lived experiences
of research participants rather than the pre-determined hypotheses testing which are based on
theory (deductive themes). At the same time, the pre-determined hypothesis can be important
to develop the structure to elicit these experiences more broadly. Identifying the qualitative
causes of adherence/non-adherence is important in planning future practical therapeutic and
preventive interventions.
Among the multitude of exercise interventions carried out to date on T2DM, the qualitative
information evaluating their success remains limited. Tulloch et al. published qualitative data
[187] on T2DM patients’ perspectives of adherence to exercise in a RCT [90] and concluded
peer support, supervision and support from family as facilitators. It is important to identify
further qualitative data generally and contextually for long- and short-term improvements of
compliance to exercise, which is continuously being debated. However it is incorrect to
assume that the factors can be same for different cultures and countries. In that context,
identifying the qualitative data on South Asian Sri Lankans will add new information to the
evidence base.
To the best of our knowledge there are no studies conducted to date where the effectiveness
of a RCT (study 1) with regard to participant qualitative experience is assessed. This
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component allowed a triangulation approach to the incorporation of quantitative and
qualitative data at the stage of results interpretation which will give contribute to a more
applicable outcome.
There is evidence to support the beneficial effects of AT/RT on glycemic control, adiposity,
anthropometry biochemistry (lipid and liver profiles) in South Asians T2DM patients. Most
documented studies conducted to date are in Caucasian and Asian Chinese ethnicities in
environments where facilities (gymnasiums and trained staff) are widely available. The 2
studies which are conducted in the region had limitations where Misra and colleagues did not
include a control group [55] in their study and Shenoy et al. did include a control group, but
the sample sizes were low (n=10 per group) [91].
Future research should plan better defined programs with much larger sample sizes for more
definitive conclusions regarding each type of exercise, which are sparse in the region and not
documented in Sri Lankans.
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2.11 Summary of gaps in literature and research questions
Despite the high prevalence of T2DM in Sri Lanka, there are no published data on the
effects of exercise in T2DM. Further, very limited studies are conducted in South Asia,
which is the home to almost one-fifth of the world’s population. The methodological
designs of the RCTs conducted to date need improvements.
Current evidence directs South Asian people with T2DM can have a better glycemic
control from RT. Since there is a difference in body composition and metabolic profile of
South Asians, the relative effect of aerobic and resistance exercise can be different to
other ethnicities studied so far. The relative effects of exercise on glycemic control,
insulin resistance, liver and lipid profiles (biochemical), visceral adiposity
(anthropometric) are not being evaluated in the current literature among South Asians and
Sri Lankans. The most appropriate mode of exercise to South Asians may need to be
identified for them to have the best outcome.
Lack of adherence/compliance is a common problem in maintaining intentional exercise.
It is uncommon to see the reasons for non-adherence being investigated from a qualitative
standpoint. It is also important to evaluate these reasons based on theoretical evidence,
which is important in planning future practical therapeutic and preventive interventions.
Effects of exercise on food preference (behavioral), is not investigated among South
Asians and Sri Lankans.
This thesis will address these gaps by conducting a randomized controlled trial to study the
effects of a supervised progressive resistance exercise program and aerobic exercise program
on behavioral, anthropometric, physical fitness, appetite and biochemical parameters in Sri
Lankan adults with T2DM who do not have contraindications to exercise. The outcomes will
be compared with each program and a control group who receive standard care. The RCT
will be designed to meet the scientific standards minimizing the deficiencies which were
observed in the past studies. Additionally, the barriers and facilitators for adherence to each
separate program will be studied, using a qualitative approach. We believe the outcome of
this study will add new knowledge to the subject area, from the South Asian region and will
positively inform the policy makers in Sri Lanka. Finally, we plan to collectively accumulate
these quantitative and qualitative outcomes to propose a culturally adaptable therapeutic
physical activity intervention to patients with T2DM in Sri Lanka.
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The novelty of this thesis is that there is no such study conducted in Sri Lanka or in South
Asia comparing all these parameters. Most of these studies to date have been conducted in
white Caucasians who have a different body composition. Secondly, addition of a qualitative
study to assess the barriers and facilitators for compliance and adherence to exercise has not
been documented in prior studies conducted to date.
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2.12 Questions and Hypotheses
Primary research questions (R) and hypotheses (H)
R1. Is there a difference between supervised RT and AT on glycosylated hemoglobin
(HbA1c) levels and %body fat, in Sri Lankan adults with T2DM?
H 1. Supervised RT is more effective in improving glycosylated hemoglobin (HbA1c) levels
and %body fat compared to supervised AT and control, in Sri Lankan adults with T2DM.
R2. What are the compliance/adherence barriers and facilitators experienced by the
participants, and do they differ between the modes of exercise intervention?
H2.Barriers and facilitators experienced by the participants for compliance/adherence are
different in each mode of exercise intervention.
Secondary research questions (r) and hypotheses (h)
r 1. What is the effect of supervised RT compared to AT on post exercise food preferences,
in Sri Lankan adults with T2DM?
h 1. Supervised RT is more effective in reducing post exercise preference for high-fat sweet
foods compared to supervised AT, in Sri Lankan adults with T2DM.
r 2. What are the effects of supervised RT compared to AT on improving insulin resistance,
blood lipid & liver profiles, muscle strength & lean mass and quality of life, in Sri Lankan
adults with T2DM?
h 2. Supervised RT is more effective in improving insulin resistance, blood lipid & liver
profiles, muscle strength & lean mass and quality of life compared to supervised AT and
control, in Sri Lankan adults with T2DM.
r 3. What are the effects of supervised AT compared to RT on improving cardiovascular
endurance and blood pressure in Sri Lankan adults with T2DM?
h 3. Supervised AT is more effective in improving cardiovascular endurance and blood
pressure compared to supervised RT and control, in Sri Lankan adults with T2DM.
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Primary Objectives
1. To determine the effect of a supervised RT program on glycosylated hemoglobin
(HbA1c) and percentage body fat in Sri Lankan adults with T2DM.
2. To determine the effect of a supervised AT program on glycosylated hemoglobin
(HbA1c) and percentage body fat in Sri Lankan adults with T2DM.
3. To compare effects of each program with standard care without exercise.
4. To identify the barriers/facilitators experienced by participants for compliance/adherence
to different modes of exercise.
Secondary Objectives
1. To determine the effects of a supervised RT program on preference for different foods,
blood lipid and liver profiles, muscular strength and lean mass, cardiovascular endurance,
blood pressure and quality of life in Sri Lankan adults with T2DM.
2. To determine the effects of a supervised AT program on preference for different foods
blood lipid and liver profiles, muscular strength and lean mass, cardiovascular endurance,
blood pressure and quality of life in Sri Lankan adults with T2DM.
3. To determine and compare effects of each program and standard care.
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Table 1.0. Hypothesized effect of each exercise mode
Hypothesis Variable/parameter Effect of each exercise
mode
Primary
Reduction of Glycosylated Hemoglobin
(HbA1c)
RT>AT
Reduction of %Body fat RT>AT
Barriers and facilitators experienced by
participants
RT≠AT
Secondary Hedonic food preference for high-fat sweet
foods:
Reduction of Explicit Liking
Reduction of Explicit Wanting
Reduction of Implicit Wanting
RT>AT
RT>AT
RT>AT
Reduction of Fasting Blood Sugar
Reduction of Fasting Insulin
RT>AT
RT>AT
Lipid profile:
Reduction of TC
Reduction of TG
Reduction of LDL
Increase of HDL
RT>AT
RT>AT
AT>RT
AT>RT
Liver profile:
Reduction of AST
Reduction of ALT
RT>AT
RT>AT
Reduction of Highly sensitive CRP RT>AT
Increase of Muscle strength RT>AT
Increase of Cardiovascular Endurance AT>RT
Reduction of Blood pressure AT>RT
Increase of Quality of Life RT>AT
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Chapter 3: General Methodology
Objectives, Methodology and Research Plan
3.1 Objectives
Primary Objectives
1. To determine the effect of a supervised RT program on glycosylated hemoglobin
(HbA1c) and percentage body fat in Sri Lankan adults with T2DM.
2. To determine the effect of a supervised AT program on glycosylated hemoglobin
(HbA1c) and percentage body fat in Sri Lankan adults with T2DM.
3. To compare effects of each program with standard care without exercise.
4. To identify the barriers/facilitators experienced by participants for compliance/adherence
to different modes of exercise.
Secondary Objectives
1. To determine the effects of a supervised RT program on preference for different foods,
blood lipid and liver profiles, muscular strength and lean mass, cardiovascular endurance,
blood pressure and quality of life in Sri Lankan adults with T2DM.
2. To determine the effects of a supervised AT program on preference for different foods
blood lipid and liver profiles, muscular strength and lean mass, cardiovascular endurance,
blood pressure and quality of life in Sri Lankan adults with T2DM.
3. To determine and compare effects of each program and standard care.
3.2 Methodology and Research Plan
3.2.1 Settings
Department of Allied Health Sciences (AHS) at Faculty of Medicine, Strength
Gymnasium and Health Center at University of Colombo (UOC) Sri Lanka for data
collection and exercise intervention implementation.
National Hospital of Sri Lanka (NHSL) for patient recruitment.
Selected private sector clinics in Colombo district for patient recruitment.
3.2.2. Funding
The research was funded by the University Grants Commission (UGC) Sri Lanka, University
of Colombo (UOC) Sri Lanka and Queensland University of Technology (QUT) Australia.
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3.2.3 Study design & Duration (Figure 3.1)
Pilot study.
Study 1: A randomized controlled trial (Objectives: Primary and Secondary -1, 2, 3).
Study 2: A qualitative study will be conducted to determine the barriers/facilitators
for compliance to different exercise programs (Primary Objective 4).
Duration: 3 years.
Time
Figure 3.1 - Research plan
3.2.4 Preliminary work and Pilot study
Preparation (October 2015-May 2016)
Institutions and Facilities: Approvals were received from the following institutions and
personnel.
o Access to and use of UOC Gymnasium. Special permission was requested and
approved by the Vice Chancellor (VC) and the Chairman of Sports Board UOC. The
gymnasium was only used by the students and staff of UOC. This special permission
was needed as the premises will be used by patients external to UOC.
o Access to and use of the UOC Health Centre for patient examination and phlebotomy.
o Approvals from Directors and respective consultants of the clinics in National hospital
of Sri Lanka and private hospitals for data collection and recruitment of participants
and conduct of investigations (Exercise ECG).
Logistics, equipment and services:
o Equipment: Standard measuring devices (Heart rate monitors, pedometers) were
purchased in Australia as they were not available in Sri Lanka. Step boxes were made
in Sri Lanka using the standard measurements as they were not available to purchase
and were not feasible to import. Equipment for skin fold assessment (Harpenden
Pilot
study
Study 1
Randomized controlled trial
Quantitative analysis
(n= 30 each for RT, AT,
Control groups)
Study 2
Qualitative study to
determine the
barriers/facilitators
More applicable
outcome/Model
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Skinfold Calliper) and other anthropometric measurements (weight, height, girths)
were purchased from Sri Lanka.
o Organising investigations to be done for data collection:
1. Standard tertiary care laboratories were contacted and quotes requested for blood
and radiological investigations (DXA scan), and most appropriate labs were
selected. Payments for 2 separate labs (blood & radiology) were organised from 2
different grants (UGC and UOC) due to high cost.
2. National Hospital of Sri Lanka (NHSL) was resourced to do the Exercise ECG and
2D echocardiogram. Dr. G. Constantine, consultant cardiologist and senior lecturer
at department of clinical medicine UOC was collaborated to the study to perform
and supervise the investigations. Cardiographers from Department of
electrocardiography were collaborated.
Recruitment of personal: Physiotherapists and pre intern medical doctors who are suitable
and qualified to be research assistants to the study were called for interviews and selected.
An administrative assistant was recruited for administrative work. Exercise instructors
were recruited.
Training:
I have clinical expertise as a sports physician with a post graduate diploma in sports
medicine. I received training at Queensland University of Technology (QUT) exercise
clinics under accredited exercise physiologists on clinical exercise prescription and
testing during the first 6 weeks of the PhD. The physiotherapists and exercise
instructors were trained by myself according to the needs of the exercise protocol
adhering to ACSM guidelines. Standard operating procedures (SOPs) were developed
to maintain uniformity (Appendix 1-4).
I had additional training on performing stress ECGs at cardiology unit NHSL.
I underwent training for Advanced Life Support (ALS) by College of
Anaesthesiologists and Intensivists of Sri Lanka which will be needed when
conducting Exercise ECGs and supervising exercise programs to people with co-
morbidities.
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Pilot study
A pilot study was carried out prior to the main study (Figure 3.1).
Participant recruitment and intervention was in line with the protocol of the main
study (Figure 3.2).
Duration - 4 weeks.
Sample - 3 participants from each group (n=3) were recruited as per the criteria.
The pilot study was conducted in the previously mentioned settings (ref 3.2.1).
Aims of the pilot study were:
To identify the feasibility and limitations in patient recruitment, allocation of exercise,
technical and logistic constraints of the program.
To observe how participants respond to, and tolerate the program.
To determine the duration of the practice period needed to teach the technical skills of
the exercise programs (preparation period).
Pilot testing of questionnaires (e.g. Information booklet).
To determine the resources and staff assistance required to conduct the main trial.
Results and improvements done
The pilot study replicated the main study design methodology. The main study was improved
based on the pilot study outcomes. The study was conducted and completed between June
and August 2016. Three (n=3) participants from each of the intervention and control groups
were recruited and randomized (N=9, Male: Female AT 1:2, RT 1:2, CN 2:1) were all
completed the intervention.
Process evaluation:
A number of strategies for documenting the implementation of the intervention were
developed with the pilot study. Standard Operating Procedures (SOPs: Appendix 1-4)
were developed for participant recruitment, randomization, screening, conducting pre-
and post-intervention measurements and implementation of the exercise intervention.
Before the commencement of the study, the methods by which they would be
documented, who would be responsible for completing the documentation and procedures
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for data entry and evaluation was decided. The investigators and exercise supervisors
were trained accordingly.
The difficulty and excessive time consumed associated with participant recruitment was
identified. A trained pre-intern medical doctor was recruited for initial participant contact.
The preparation period was designed especially to determine how the participants
responded to the exercise protocol. The duration of time required for participants to be
comfortable with the desired dose and intensity of the aerobic exercises was observed.
How participants adapted to the resistance training techniques was also monitored. It was
evident that sedentary participants who had never been exposed to structured exercise
were able to reach the adequate dose, intensity and the desired techniques within 4 to 5
sessions (across approximately 2 weeks) of supervised training. Participants reported that
when they started coming to the exercise sessions it was easy to continue to the next
session. What was difficult, was to initiate the first exercise session.
Pre testing of the exercise protocols and questionnaires were undertaken. Protocols were
modified to facilitate accuracy of data entry and improve feasibility. The feasibility of the
exercise protocol was improved by confirming the frequency the participants can attend
(2 session/week). Dose, initial intensity and progression sequence of exercises were
decided. Reach for the participants (logs of participant attendance, and participant
experience regarding the intervention) were included in the information booklet. Testing
was done in safety and first aid protocols. The Leeds food preference computer based
questionnaire was tested according to cultural acceptance with the guidance of Dr.
Graham Finlayson from University of Leeds UK. Standard Operating Procedures (SOPs)
for conducting the qualitative study were formulated.
The supervised exercise admission was conducted and physiotherapists and exercise
instructors were trained in the standardized administration of the exercise intervention
during which steps were taken to reduce inter-rater variability.
The accuracy of methods and uniformity of pre and post intervention measurements
(physical, blood, radiological) were assessed. Specific time points of measuring
intervention outcomes were identified. Feasibility was assessed to liaise with laboratories
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and patient transport (for radiological and exercise ECG investigations), and measures
were taken to minimize delays. The independent outcome assessors of the laboratories
were met in person and were briefed about the specific needs. The blood sample transport
was organized and detailed work was undertaken to collect blood at the same time of day
and day of the week and to transport to the laboratory to maintain uniformity.
The availability of the principal investigator and exercise administrators at all times
contributed to retention of the participants. Technical and logistic constraints of
coordination between laboratories and institutions was identified and improved. Access to
the gymnasium and the investigation laboratories were improved by providing free access
to car parking and transport facilities when needed.
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3.2.5. Study 1: RCT
3.2.5.1 Trial registration
Sri Lanka Clinical Trials Registry; SLCTR/2016/017. Date registered 17.06.2016. Universal
trial number U1111-1181-7561.
The protocol was approved by the Ethics Review Committee Faculty of Medicine University
of Colombo (EC/14/071) Sri Lanka and University Human Research Ethics Committee
(UHREC) Queensland University of Technology (1600000766) Australia.
3.2.5.2 Study population and sampling
The study population was recruited according to the inclusion and exclusion criteria, from the
patients attending the Medical and Diabetic clinics of NHSL and private sector clinics.
Prior approval was taken from the Director of NHSL and the consultant physicians’ in-
charge. Patients attending selected private sector clinics in Colombo district were recruited
after prior approval from the consultant physician concerned. Participants who were eligible
but did not want to participate were documented and the reason for non-consent was
identified (Recruitment register).
3.2.5.3 Inclusion and Exclusion criteria
Inclusion criteria
Males and females aged 35-65 years.
Sri Lankan origin.
Diagnosed with T2DM within last 10 years.
Informed written consent.
Exclusion criteria
Patients who refused to participate in the study.
Patients who are not of Sri Lankan origin.
Blood HbA1c levels <6.5% or >11.5%.
History of significant cardiovascular (ischemic heart disease etc.), respiratory (asthma
chronic obstructive pulmonary disease etc.), musculoskeletal diseases (osteoarthritis
of major joints etc.).
On insulin or thiazolidinedione therapy/other than standard oral hypoglycemic agents.
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Advanced diabetes induced end-stage organ damage (vascular, retinopathy,
nephropathy, neuropathy, retinal hemorrhage or detachment, history of laser therapy).
Current participation in supervised RT or AT.
Engaged in RT in previous 6 months.
People with cognitive impairment, intellectual disability, or mental illness.
Pregnancy or planning pregnancy during the next 6 months.
3.2.5.4 Informed consent
Written informed consent was obtained from all participants prior to their entry into the
study.
3.2.5.5 Sample size
The variable expected to change due to the intervention is glycosylated hemoglobin (HbA1c),
the main parameter to check long-term glycemic control [7]. An absolute decrease of 1% in
HbA1c levels has been associated with a 15-20% decrease in major cardiovascular disease
events and 37-40% decrease in microvascular complications [70, 90]. Studies have reported
that structured AT or RT had statistically and clinically significant reduction of absolute
HbA1c value by about 0.6% [68, 70]. Sample size was calculated as approximately 30
participants per group to have 80% power to detect a moderate 0.65-SD difference in HbA1c,
with a α value of 0.05. Accordingly, 90 participants were planned to be selected and allocated
to 3 groups. Approximately 15-25% additional participants were recruited to account for the
estimated drop-out rate (n=38). Drop-outs were documented separately (Drop-out register).
RE group (n=30), AE group (n=30), Control group (n=30)
3.2.5.6 Randomization
The basic benefits of randomization are to eliminate selection bias, balance the groups with
respect to confounding or prognostic variables, and to form the basis for statistical tests.
Different randomization techniques are currently used in clinical trials. The commonly used
simple randomization can generate similar numbers of subjects among groups in large
clinical research but is problematic in relatively small sample size clinical research (n<100),
resulting in unequal numbers among groups. The block randomization technique ensures a
balance in sample sizes but the groups are rarely comparable due to unequal distribution of
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the covariates. The stratified randomization method controls for the possible influence of
covariates. The limitation of this method is that it works only when all participants have been
identified before group assignment.
Current RCT recruited participants in an ongoing basis continuously by a roll-in method. As
discussed above, in such instance stratified sampling was not applicable. Adaptive covariate
randomization was selected for this RCT as it minimized the allocation bias and balanced
important covariates among groups. It has been recommended as a valid randomization
method for clinical research with low sample sizes [188]. One limitation of this technique
was that group assignments sometimes became highly predictable going against the basic
concept of randomization. Therefore, a small number of participants were initially randomly
assigned into the groups before the covariate adaptive randomization technique was applied.
3.2.5.7 Blinding
The participants were randomized into groups where the exercise supervisors/data collectors
were blinded. Blinding the exercise supervisors and the participants to the intervention is not
possible in exercise intervention trials. However, blinding of the outcome assessors was
undertaken where the primary outcomes (1. glycemic control and 2. % body fat) were
measured at independent tertiary care laboratories by trained staff. The investigators did not
have access to the laboratory procedures [68]. Data analysis was completed by the first author
on a de-identified database.
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Figure 3.2 Flow chart of sampling, recruitment and progression of RCT/Study 1
No intervention.
Followed up
Pre-intervention measurements of behavioral, fitness, appetite and biochemical parameters
parameters
Control group (CN)
n=30
Screening
Clinical History
Physical Examination
RT-Intervention group
n=30 AT-Intervention group
n=30
Recruitment from clinics
Inclusion/exclusion criteria
Informed written consent
Post-intervention measurements of behavioral, fitness,
appetite and biochemical parameters after 12 weeks
RT Program
Randomly allocated to groups
Screening Investigations
2D Echocardiogram
Stress ECG
Abnormality detected
Patient advised, excluded
and referred for specialist
care
AT Program
No Abnormality
Included in Study group
N=90
Exercise practice period
2-4 weeks
Qualitative study
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3.2.5.8 Study instruments
Study 1: Randomized controlled study (Main study) data collection.
Information booklet
Form A - Personal information.
Form B - Screening: The physical activity readiness questionnaire (PAR-Q) and
history, physical examination and investigations (stress ECG, 2D echocardiogram).
Form C - Pre and post intervention measurements (anthropometry, biochemical,
radiological, International physical activity questionnaire (IPAQ- Long form) and SF 36
Quality of life assessment).
Form D - Exercise protocols (Resistance and Aerobic exercise groups).
Computer-based Leeds Food Preference Questionnaire (LFPQ)
Change in preference for a particular type of food (high fat: sweet, high fat: non sweet, low
fat: sweet, low fat:non sweet) was assessed by a computer-based validated questionnaire.
Refer to section 4.5 for detailed description.
Dietary Intake
Habitual dietary intake before the interventions and during the interventions, was not
measured. There was no attempt to control for dietary intake. This was a large-scale study,
with many measurements. Adding a dietary intake measure would have been a huge burden
for participants in addition to the challenges; practical- and validity-related.
Study 2: Qualitative study data collection
In-depth interviews (IDIs).
Recruitment and Drop-out registers.
Participant assessment and documentation
The pretested information booklet recorded interviewer-administered data collected from
participants. Initially, demographic data (name, age, gender, marital status, occupation and
income level), screening data for eligibility, and background physical activity levels were
documented. During the study, pre and post intervention behavioral, appetite, anthropometry,
physical fitness, biochemical parameters (form C) and the individual exercise protocols and
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details of each exercise session (24-30 sessions) (form D) was documented by the exercise
supervisors.
3.2.5.9 Screening
Screening was undertaken using thorough medical history and physical activity readiness
questionnaire (PAR-Q) [189] followed by a physical examination conducted by a qualified
medical practitioner. The physical activity readiness questionnaire (PAR-Q) is a screening
tool used before planning to start an exercise program [190]. It is often used by fitness
trainers or coaches to determine the safety or possible risk of exercising for an individual
based upon their answers to specific health history questions [191]. The objective of the
screening was to exclude any condition mentioned in the exclusion criteria and ensure safety
for progressive exercise. Then eligible participants were randomly allocated to one of the
exercise groups. They underwent a 2D Echocardiogram conducted by a consultant
cardiologist followed by Exercise/Stress electrocardiogram/ECG (see figure 3.2) conducted
by trained staff and supervised by a consultant cardiologist. Patients who failed the test were
excluded from the study and referred for specialist care. Patients who were not documented
with impaired cardiac tolerance were detected by this method and patient safety was ensured.
3.2.5.10 Intervention
The exercise programs/interventions have been developed by the first author with the help of
sports medicine physicians, accredited clinical exercise physiologists and physiotherapists.
The theoretical basis for the intervention was gleaned from current literature and guidelines
from American College of Sports Medicine (ACSM) [192]. Feasibility, adaptability and
safety was tested and further modified with the pilot study.
Preparation period
Eligible participants took part in an educational practice period at University of Colombo
strength gymnasium 2 weeks prior to start of the intervention proper. They were trained in
the allocated exercise types where tolerance was monitored. The pre intervention (i.e.,
baseline) parameters were measured during this period (see Figure 3.3).
Intervention fidelity
Three exercise supervisors were present at each class and were available for participants, one
to one. Supervision was provided in a uniform manner. At random points during the
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intervention, an independent assessor observed the classes and monitored for content
consistency using a checklist on explicit areas of the exercise protocol. The principal
investigator checked the exercise protocol log daily and the independent assessor reviewed it
at random intervals to check that the intervention was delivered as it was intended.
RT-Intervention group
Participants followed a supervised progressive resistance training program adhering to
ACSM, American Diabetes Association (ADA) guidelines [10]. Each exercise session was ~
60-75 minutes in duration, 2 times per week continuously for 12 weeks. Duration of each
session was tailored according to the capacity of each individual and progressed accordingly.
Exercise duration per week was maintained for approximately 150 minutes. Each session
consisted of a warm-up, a resistance training component and a cool-down phase. There was a
48-hour rest period between each session. With regard to frequency of sessions, a recent
review stated there is no significant difference in benefits between 2/week of RT compared to
3/week of RT [89]. The 12-week exercise program allowed adequate time for measurable
changes in the group (e.g. muscle fiber hypertrophy typically occurs 6-8 weeks after initiating
RT).
The resistance training phase targeted biceps, triceps, deltoid and upper pectoral muscles,
core, quadriceps, hamstrings, calf, trapezius, latissimus dorsi and gluteal muscle groups.
Seven exercises targeted these muscle groups in the upper body (shoulder press, lateral pull
down and biceps curl), lower body (leg press/squat, leg extension, heel lifts) and core
(abdominal crunches starting with pelvic and core muscle activation). Initial resistance for
each exercise was decided individually by testing strength via 1 repetition maximum/1RM
[10, 90]. The volume of exercise progressed from 1 set of 8 repetitions up to 3 sets (1x8 to
3x8) and then with increasing resistance according to individual capacity. One review
reported that an RT program with 21 or more sets per session had a larger effect size than one
with fewer than 21 sets per session [89]. Body resistance, free weights and exercise machines
were used in a circuit manner in the exercise sessions to improve variety. Supervision was
provided by the trained principal investigator, a qualified physiotherapist and physical
training instructors.
Advice on the importance of improving physical activity was given during sessions (every 2
weeks) and participants were encouraged to attend all sessions. Further, participants were
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advised not to participate in any structured physical activity/exercise program apart from the
prescribed SL-DARTS program. Usual standard care in the management of T2DM was
continued and no additional information regarding dietary modifications was given.
Behavioral, appetite, anthropometry, physical fitness parameters were measured pre- and
post-intervention (Figure 3.2).
AT-Intervention group
This group followed a supervised progressive aerobic training program with exercise
intensity developing up to 60–75% of heart rate max (HRmax). Initial baseline endurance
capacity was measured using the submaximal graded exercise tolerance step test (YMCA 3
Minute Step test) [193] and an exercise ECG; which assessed cardiovascular endurance and
aerobic capacity. Heart rate was monitored using Polar heart rate monitors while exercising.
During the AT program, brisk walking on a treadmill, stepping up and down on a stepper,
and stationary cycling was used alternately. Exercise intensity was progressed according to
individual tolerance, graded by HRmax and the rating of perceived exertion (RPE) using the
Borg 6-20 scale. Initially, participants’ workload was adjusted to achieve 60% of HRmax and
8-9 RPE for 20-30 minutes and progressed to 75% of the HRmax [90] and an RPE of 12-13 for
up to 75 minutes. Each session was 75 minutes in duration, 2 times per week (150 minutes
per week) continuously for 12 weeks. Total duration of the exercise/week was the same as
the RT group and the duration of each session was tailored initially according to the capacity
of each individual and progressed accordingly.
Control group - Active control
This group was provided standard care during their normal clinic visits to a consultant
physician prescribing medication and general health education. There will be no specific
instructions given or skills taught regarding exercise nor additional information regarding
dietary modifications. The control group also had pre and post intervention measurements of
all parameters and background physical activity measurements. This group of participants
were contacted via telephone once every 2 weeks during the 12-week period and were met in
person in the middle of the intervention (6-7 weeks). If participants wanted to exercise at
home during the study or wanted to stop, they were excluded from the study.
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Background physical activity
Background physical activity was assessed in all participants using standard pedometers
(Yamax, Digi walker, CW- 600 Japan) worn except when showering or sleeping, for 7 days
between weeks 6 and 7 of the intervention. Background activity is the mean daily total step
count for the days the pedometer was worn excluding steps during scheduled exercise
sessions. Also, the International Physical Activity Questionnaire (IPAQ) long version [194]
was used pre and post intervention to assess the general physical activity level of participants.
Participants were advised not to engage in any additional exercise outside the prescribed
program during the 3 months. These two methods assessed the activity pattern of participants
at home, outside the supervised exercise program.
Safety
There is the possibility of a reduction in blood sugar levels below normal (hypoglycemia)
during and after exercise. Participants were advised about hypoglycemic symptoms during
and after the exercise program and about appropriate self-management procedures. Pre- and
post-exercise capillary blood glucose were measured at the initial period and as required; to
avoid hyper/hypoglycemia during the intervention [195]. Participants with a daily blood
glucose level (BGL) exceeding 300 mg/dL or 16.7 mmol/L [10] were not allowed to engage
in exercise during that day and were directed to appropriate medical care. Participants with a
BGL less than 100 mg/dL or 5.5 mmol/L [10], were provided with 15-30 g of glucose and re-
assessed by a qualified medical doctor on BGL (<100 mg/dL) and signs and symptoms of
hypoglycemia. They were allowed to continue/discontinue accordingly. An adequate amount
of carbohydrate (glucose) and drinking water was available to participants during activity to
avoid hypoglycemia and dehydration. Blood pressure was monitored before each session and
emergency drugs and access to hospital was available in case of an emergency. Special
precautions were taken to prevent injuries and blisters in patients’ feet during the program.
They were screened in the initial check-up and monitored during the program.
Adherence to the intervention
Continuous motivation and advice on adherence to the program was given during sessions
and one-to-one attention was provided. The principal investigator was available at any time
to meet participants in person. Standard care in the management of T2DM was continued
without any additional information regarding dietary modifications. Supervision was
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performed by the trained principal investigator, qualified physiotherapists and physical
training instructors.
Change in DM medication
Diabetes medication type and dosage were assessed by a detailed inspection of patients’
clinic records with visual confirmation of prescription drugs. Participants were categorized as
either increased, decreased, or no change in diabetes medications based on baseline and
follow-up medication dosages.
3.2.5.11 Outcome measures
All outcomes were measured pre (within one week before the start date of the intervention)
and post intervention (within 1-2 weeks after the intervention). Change in pre and post
intervention glycemic control (HbA1c) and change in percentage body fat were the primary
outcomes. The change in lipid profile, liver profile, chronic inflammatory state,
anthropometric measures (height, weight, body mass index/BMI, and waist / hip / mid-thigh /
mid-arm circumferences), muscular strength, cardiovascular endurance, blood pressure, food
preference, Quality of life were secondary objectives/outcomes.
Primary outcomes
1. Change in glycemic control
The primary outcome was pre and post intervention absolute change in glycosylated
hemoglobin (HbA1c) levels. HbA1c is the accepted parameter to monitor long-term glycemic
control (normal values are 4 - 6.5%) [33]. Additionally, fasting blood sugar levels (FBS) and
fasting insulin (FI) levels were measured and Hemostatic Modal Assessment for Insulin
Resistance (HOMA-IR) was calculated to further assess and compare the change in insulin
resistance status. The venous blood sample was collected after an overnight fast by a trained
medical officer/investigator and transported to a standard tertiary care laboratory for analysis.
Laboratory technicians (outcome assessor) were blinded for the study.
2. Body composition
Total body fat percentage was measured via Dual energy X-ray Absorptiometry (DXA)
full body scan [110], a gold standard assessment of body composition. Additional details
on regional body fat percentages were also analyzed. The DXA scan was completed in a
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standard tertiary care laboratory by a trained technician (outcome assessor) who was
blinded to the study participants.
Body composition was also assessed via seven site skin fold thickness measures (triceps,
chest, sub scapular, axillary, mid-thigh, abdominal and suprailiac skin folds) [195] using
a Harpenden skin fold caliper by the trained principal investigator. All measurements
were taken in the mornings between 0900 -1000 am by the same investigator to maintain
consistency and inter-rater reliability. The ISAK (International Society for the
Advancement of Kinanthropometry) methodology and American College of Sports
Medicine Guidelines were used [111].
Secondary outcomes
1. Lipid profile, liver profile and chronic inflammatory status
Additional blood parameters were measured using the same blood sample (pre and post
intervention) in the laboratory used to test the HBA1c/FBS/FI levels.
The absolute change in values of plasma lipid profile; plasma Total Cholesterol (TC),
Triglycerides (TG), High Density Lipoproteins (HDLC), Low Density Lipoproteins
(LDLC) will indicate the changes in metabolic and the cardiovascular risk of the
participant [196].
The change in highly sensitive serum C-reactive protein (hs-CRP) was measured to
identify the ongoing chronic inflammatory status which is a predictor of the future
cardiovascular risk [197].
Serum Aspartate aminotransferase/Alanine aminotransferase (AST/ALT) levels were
measured to assess the liver cell damage as part of the metabolic derangement in
metabolic syndrome and T2DM [198].
2. Anthropometric parameters (Secondary outcomes)
Basic anthropometric measurements were taken in the mornings between 0900 -1000 am
adhering to ISAK guidelines by the trained principal investigator who is a qualified medical
practitioner. Height was measured while the participant is barefoot to the nearest 0.1 cm
using a portable stadiometer (Seca 213, Germany). Weight was measured (wearing light
clothing without shoes) using an electronic weighing scale (Seca 813, Germany) and
recorded to the nearest 0.1 kg. Body Mass Index (BMI) was calculated using the standard
calculation (weight/height 2 kgm-2). Waist, hip, mid-arm, mid-thigh circumferences were
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measured using a non-elastic measuring tape (Seca 201, Germany) to the nearest 0.1 cm. A
mean value was recorded after three consecutive measurements [195].
3. Physical fitness parameters (Secondary outcomes)
A variety of measures were performed to assess the change in cardiovascular endurance,
electrocardiographic state of the heart and muscular fitness status of each participant and
screen them for suitability for progressive exercise.
I. Exercise ECG was performed on participants before the start of the intervention at a
tertiary care hospital (National Hospital of Sri Lanka/NHSL) electrocardiographic
laboratory under the supervision of a consultant cardiologist, medical officers and
trained cardiographers. Principal investigator had a special training prior, to oversee
exercise ECGs. The consultant cardiologist performed a 2D Echocardiogram to
exclude any structural and functional abnormality of the heart as a pre-requisite to the
exercise ECG. This was used as part of the screening protocol to exclude
cardiovascular risk.
The standard Bruce protocol was used on treadmill walking with the starting point (ie,
stage 1) as 1.7 mph at a 10% grade (5 METs), stage 2 in 2.5 mph at a 12% grade (7
METs) and stage 3 in 3.4 mph at a 14% grade (9 METs). This protocol included 3-
minute periods to allow achievement of a steady state before workload is increased
[199]. The universal standards and safety precautions were adhered with the
availability of emergency resuscitation facilities.
II. The 6-minute walk test (6MWT) required the participants traverse a 10 m course
(out and back) walking (not running) as far as possible for 6 minutes. Ideally it is
recommended to use 20 m course but the tract which was inside the gymnasium (air-
conditioned controlled environment) allowed only for 10 m distance. Standing rests
were allowed if needed, with the request that participants resume walking as soon as
possible, so they could cover as much ground as able over the 6 minutes. At one-
minute intervals the participants were told “you are doing well” or “keep up the good
work” and were informed of the time remaining. Immediately after completion of the
test the participants’ heart rate was obtained by a polar hear rate monitor. At
completion the distance they walked was documented [200].
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III. YMCA 3-Minute Step Test (3MST) was used to measure the heart rate changes with
acute progression of exercise. In the gymnasium, the participants stepped on to a 30
cm bench according to metronome cadence, which was set at 96 beats per minute for
a stepping rate of 24 steps per minute. They stepped up and down for 3 minutes, the
heart rate was monitored throughout, and recorded at the end of each minute.
Participants stopped at the end of the 3rd minute on completion of the test and sat for 1
minute. The heart rate was measured at the end of 4th minute. The recovery of heart
rate during the first minute immediately after exercise gave an estimate of autonomic
reactivity of heart and in turn the assumption of cardiovascular fitness [193, 200].
IV. Systolic and diastolic blood pressures were measured using an Omron HEM-7130
electronic sphygmomanometer.
V. Muscular strength: One Repetition Maximum (1RM) was measured using ACSM
guidelines via biceps curl, shoulder press and leg press for upper body and lower body
major muscle groups [195].
4. Liking and wanting of food (Secondary Outcome)
Study instrument
Components of food reward and preference were assessed by the Leeds Food Preference
Questionnaire (LFPQ), which is a validated tool/computer procedure to measure liking and
wanting for different foods [173]. LFPQ is identified as to detect more subtle exercise-
induced alterations in the hedonic processes that influence food preferences compared to the
traditional methods that was used before.
The computer procedure comprised of two tasks designed to assess 1) explicit liking, 2)
explicit wanting and 3) implicit wanting, for the same visual food stimuli. The visual food
stimuli were selected from a database of photographs from Sri Lankan foods and categorized
according to their fat content and taste properties into one of four separate categories: high fat
non sweet (HFNS); low fat non sweet (LFNS); high fat sweet (HFSW); and low fat sweet
(LFSW). Each category was represented by 4 different foods; hence a total of 16 different
food stimuli were presented in the procedure (Table 3.1).
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To measure explicit liking, a single food item was shown in the computer screen and the
participants rated “how pleasant would you find the taste of this food right now?” on a Visual
Analogue Scale (VAS) of 100-unit/mm which was presented on-screen beneath each food
stimulus. To measure explicit wanting the question was “how much do you want to taste this
food right now?” Each end of the scale was anchored by the statements “not at all” and
“extremely”. The participants used the mouse to move a centered cursor along the line to
indicate their response. When a rating was made, the procedure automatically cycled to the
next stimulus trial. Mean ratings for each food category (HFSW, LFSW, etc.) were
automatically computed [173].
To measure implicit wanting, a paired presentation of food items was shown, where
participants had to select their most wanted food (“select the food which you most want to eat
right now”) as quickly and accurately as possible. As participants were not aware of the
measurement of their reaction time for each choice, this measure provided an indication of
non-verbal, implicit motivational forces. The procedure uses a ‘forced choice’ reaction time
measure of implicit wanting. The reaction times were transformed to a standardized ‘d-score’
(D-RT) by the computer program. The lower the D-RT, the greater the implicit wanting for
that food category relative to other categories in the task [173].
Procedure
Participants arrived in the morning at 0830am to the Health Center of UOC where all pre-
and post-intervention physical examinations were conducted in the SL-DARTS. They either
brought their breakfast or had their meal at the adjacent canteen to the Health Center
immediately before the procedure. The participants were asked to eat a similar sized and
composition meal they would otherwise have on a typical day.
They were guided by the investigators on how to conduct the test. Initially a practice trial was
conducted with the help of the investigator. When the participant assured competence,
adequate privacy was given to complete the procedure. The LFPQ was completed pre and
post intervention (Within one week after the completion of the last exercise session).
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Table 3.1 List of Sri Lankan foods in the Leeds Food Preference Questionnaire (LFPQ)
High-fat non-sweet
(HFNS)
Low-fat non-sweet
(LFNS)
High-fat sweet
(HFSW)
Low-fat sweet
(LFSW)
Salted peanuts Potato curry Icing cake Fruit salad
Roast chicken Cream crackers Watalappan/pudding Candies
Boiled egg String hoppers Milk chocolate Wafers
Craft cheese Rice Ice cream Banana
5. Quality of Life (QoL) of the participants (Secondary outcome)
Study instrument
Change in the Quality of Life was assessed by pre and post intervention self-administration
of the SF-36 quality-of-life outcomes questionnaire [201]. The SF-36, published in 1992 by
Ware and Sherbourne, is a result of the Medical Outcomes Study. The SF-36 has been
previously translated into the Sinhala language and has been validated in Sri Lanka. The SF-
36 weighs eight (8) health scales, and a higher score indicates better health.
The eight scales are detailed below:
1. Physical functioning. Refers to limitations faced in daily life due to health problems.
Low scores on this scale represent an individual who faces limitations in physical
activities such as climbing stairs, carrying a grocery bag or bathing/dressing. A high
score indicates someone who completes such activities with little or no limitations.
2. Role limitations due to physical health. Low scores on this scale characterize someone
who faces many limitations in work and other daily activities due to health problems,
while a high score represents someone who faces no limitations with daily activities.
3. Role limitations due to emotional problems. A low score represents someone who
faces many problems with work and other regular activities due to poor emotional
health, while a high score signify persons who have no problems with work or other
activities due to emotional health.
4. Energy/Fatigue. Low scores on this scale are representative of a person who feels
tired and worn out most of the time, while a high score represent someone who feels
energetic all the time.
5. Emotional wellbeing. This scale assesses psychological distress. Low scores are a
characteristic of persons who feel high levels of anxiety and depression, while a high
score represents those who are happy, calm and peaceful.
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6. Social functioning. This scale assesses the extent to which health complications
interfere with social activities. A low score is indicative of someone who faces
difficulty in regular social activities due to physical or emotional problems. A high
score signifies someone who partakes in regular activities without interference due to
physical or emotional health.
7. Pain. This scale examines pain frequency and pain interference with daily roles. Low
scores indicate a person who experiences severe and very limiting pain, while high
scores signify individuals who experience no pain or pain related limitations.
8. General health. This scale assesses individual perception of general health. Low
scores are typical of an individual who perceives their health to be poor and expect it
to worsen, while a high score indicates someone who sees their health as excellent.
Data collection and analysis (QoL)
The participants completed the questionnaire at the beginning of the intervention (session 1)
and at the end of their intervention period (within one week of the last session). Most
participants completed the questionnaire on site, but when necessary, it was taken home to be
completed and returned at a later date (e.g., when the patient did not have their reading
glasses).
The SF-36 was scored according to the guidelines provided by the RAND Corporation [202].
Scores ranged from 0-100, with higher scores indicating better health. Additionally, effect
size (Cohen’s d) was assessed to determine change effect of each scale. The effect size of 0.2
was considered small, 0.5; medium and 0.8; large.
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Recruitment
from clinics
Run-in/preparation
period
(week -4 to week -1)
Study 1
RCT
(week 0 to week 12)
Study 2
Qualitative study
(after week 12)
w-4 w-1 w1 w4 w6 w8 w12
Figure 3.3 Specific data collection time points in the program
• Screening for
eligibility
• Physical
Examination
• IPAQ+QOL
• Anthropometry
• Fitness
measures
• Blood
investigations • Appetite
measures
• Physical
Examination
• IPAQ+QOL
• Anthropometry
• Fitness
measures
• Blood
investigations • Appetite
measures: post
intervention
In depth
interviews
Pre intervention
measures
Post intervention
measures
Personal
details
Screening
of clinic
records
Background
physical activity
measurement
Pedometer step
count / one week
(7 days)
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3.2.6 Study 2: Qualitative study- Methodology
Primary outcome
To identify the barriers/facilitators experienced by participants for compliance/adherence to
different modes of exercise programs. This was the primary objective No: 4 of the main
objectives.
Study instruments:
1. In-depth interviews (IDIs).
2. Recruitment and Drop-out registers.
Methodology
Critical literature review was conducted to understand the reasons for exercise adoption
and adherence. Most widely used evidence based cognitive behavioural approaches were
reviewed. These behavioural theories were selected based upon their scientific evidence
demonstrating efficacy. The themes to be discussed in the in-depth interviews were selected
from these behavioural theories (Table 5.1).
(A conceptual model was developed (FITTSBALL) combining these behavioral theories to
the leading technical approach (FITT) to exercise prescription. The objective was to describe
the exercise supervision process (Appendix 6).
Qualitative study was conducted to assess the response of the participants who adhered to
exercise behaviour and completed the program. In-depth interviews (IDIs) were conducted
to identify the barriers/facilitators experienced by participants for compliance and adherence
to different modes of exercise programs. Documented data from recruitment and drop out
registries were used during analysis.Participants who only participated in the exercise
intervention were invited in to the study after completing the exercise program (study 1). This
was carried out within one week after the last session (session 24) of the intervention.
In-depth interviews (IDIs)
Thirty one (31) IDIs (IDI1-IDI31) were conducted by the principal investigator and assisted by
a trained assistant. Face to face interviews were conducted maintaining privacy using a set of
pre-determined semi-structured open ended questions based on the concepts derived from
behavioral change models. The themes were regarding; the stage of behavioral change they
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are in, knowledge of exercise, individual’s beliefs, perceived ability, limitations/barriers and
facilitators experienced during the prescribed exercise programs. How they individually
managed/not managed them, and feedback regarding improvements (Table 5.1).
Duration of each IDI was 15-30 minutes. The facilitator provided guidance, maintained
focus, stimulated constructive expression, regulated the flow of discussion and ensured time
adherence, while maintaining a neutral stance on contents of discussion. Adequate time was
allowed to all respondents to fully explain their own opinions, perceptions and experiences.
During the interviews written notes were taken and the responses from participants were
audio recorded. Emotional responses were also recorded. Consent was obtained from the
participants for this process. When data saturation occurred, interview was stopped. The point
of data saturation occurred when participants start mentioning the same facts and ideas they
mentioned before. The number of interviews (N=31) conducted were determined by data
saturation which was revealed during concurrent analysis.
Recruitment and Drop out registries
The reasons for non-consent to the intervention( SL-DARTS) and drop out from it were
extracted from the recruitment and drop out registries and were used during analysis of data
(Chapter 5: Table 5.2).
3.2.7 Data and Statistical analysis
Quantitative data analysis
The data was processed and analyzed by the statistical software SPSS version 20, using
standard statistical tests. To measure the baseline (pre intervention) and post intervention)
absolute changes in glycaemia, anthropometry, body composition, metabolic parameters,
fitness parameters, liking/wanting and quality of life across the groups; a linear mixed model
analysis for repeated measures that included the covariates age and sex were used.
The SF-36 was scored according to the guidelines provided by the RAND Corporation [202].
Scores ranged from 0-100, with higher scores indicating better health. Additionally, effect
size (Cohen’s d) was assessed to determine change effect of each scale. The effect size of 0.2
was considered small, 0.5; medium and 0.8; large.
The VAS scores for explicit liking and wanting and standardized‘d-score’ (D-RT) for
implicit wanting for food in LFPQ were analyzed by using E-prime software.
The effect p<0.05 was considered statistically significant.
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Qualitative data analysis
The facilitator and two observers analyzed their respective IDI using their notes (verbal and
non-verbal responses of participants) and the tape-recorded data collectively immediately or
within twenty-four hours after the conclusion of the IDI. The audio recorded data were
transcribed, translated and the transcripts were coded. Each interview produced one complete
document, and all documents were collectively analyzed by the research team.
Directed content analysis of qualitative data was conducted with the assistance of NVIVO
v10.0 (QSR International, Southport, UK). The topics/themes were selected prior to the
analysis and participants’ responses were grouped under these topics/themes. The differences
in coding were resolved via discussions by a group of independent reviewers.
The data were stored for future use after the completion of the study for future studies.
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Chapter 4: Results & Discussion- Study 1
Randomized Controlled Trial - The effects of supervised aerobic and resistance exercise
training on Sri Lankan adults with type 2 diabetes mellitus.
4.0 Recruitment, Intervention and General Characteristics
Recruitment
The SL-DARTS was conducted from May 2016 to July 2017. The results of Study 1 - the
Randomized Controlled Trial - are presented. Figure 4.1 shows the flow of participants from
recruitment to the end of the intervention. A total of 272 potential participants were contacted
and assessed for eligibility. The 148 eligible participants entered screening and 106 were
selected. The most common reasons for exclusion were; not interested to continue (70%) and
distance to travel and time commitments (23%). The participants were randomized into
Aerobic Training (AT), Resistance training (RT) and Control groups (CN). A predetermined
number for each group was calculated with adequate power (n=30). Additional participants
were recruited to allow for drop-out of 15-20%. Recruitment continued until the required
number was achieved (n=38) per each group. All 106 entered the run-in/practice phase and
started the intervention. Out of the 23 who dropped out (less were from CN) of the study, the
majority had personal commitments (loss of close relatives, difficulty in attending
continuously, time constraints), 3 could not proceed because of medical conditions (with the
result of a road traffic accident, prolonged viral fever, post viral arthritis, etc.).
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Assessed for eligibility and
invited to partake (n=148)
Excluded (n=42)
Not interested: 29
Time commitment: 7
Distance/Travel: 3
Medical condition: 1
Too active: 2
Randomly allocated (n=106)
Aerobic (n=38) Resistance (n=38)
Control (n=36)
Dropped out (n=10)
Personal/Time commitment: 6
Medical condition: 1
Could not be contacted: 3
Dropped out (n=10)
Personal/Time commitment: 5
Could not be contacted: 3:
Medical condition: 2
Dropped out (n=6)
Personal/Time
commitment: 5
Medical condition: 1
Completed trial
Analysed (n=28)
Missing data: 2
Completed trial
Analysed (n=28)
Missing data: 2
Completed trial
Analysed (n=30)
Missing data:4
Figure 4.1.1 Participant flow diagram
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Table 4.1.1 Baseline characteristics
Characteristic
Total
(N=86)
Aerobic
Training
(n = 28)
Resistance
Training
(n = 28)
Control
Group
(n=30)
Male/Female, n/n 40/46 11/17 13/15 16/14
Mean age (SD), Y 50.1 (8.7) 52.0 (9.8) 49.0 (9.2) 49.3 (7.0)
Sinhala ethnicity/othera, n/n 83/3 27/1 26/2 30/0
Income, n / (%)
Rs. 7000-12999
1 (1.2)
1 (3.6)
0
0
Rs. 13000-24999 4 (4.7) 1 (3.6) 1 (3.6) 2 (6.7)
Rs. 25000-49999 25 (29.1) 5 (17.9) 7 (25.0) 13 (43.3)
Rs. 50000-74999 19 (22.1) 5 (17.9) 6 (21.4) 8 (26.7)
Rs. >75000 35 (40.7) 15 (53.6) 13 (46.4) 7 (23.3)
Occupation, n / (%)
Professionals
17 (19.8)
4 (14.3)
6 (21.4)
7 (23.3)
Technicians & associate professionals 16 (18.6) 6 (21.4) 3 (10.7) 7 (23.3)
Clerical support workers 9 (10.5) 3 (10.7) 3 (10.7) 3 (10.0)
Services & sales workers 3 (3.5) 1 (3.6) 1 (3.6) 1 (3.3)
Craft & related trade workers 4 (4.7) 2 (7.1) 2 (7.1) 0
Plant & machine operators & assemblers 7 (8.1) 0 1 (3.6) 6 (20.0)
Otherb 30 (34.9) 12 (42.9) 12 (42.9) 6 (20.0)
Level of education, n / (%)
Grade 6-10
2 (2.3)
1 (3.6)
0
1 (3.3)
Qualified G.C.E (O/L) 10 (11.6) 2 (7.1) 1 (3.6) 7 (23.3)
Qualified G.C.E (A/L) 44 (51.2) 16 (57.1) 16 (57.1) 12 (40.0)
Certificate or Diploma 11 (12.8) 4 (14.3) 3 (10.7) 4 (13.3)
Graduate 8 (9.3) 3 (10.7) 4 (14.3) 1 (3.3)
Postgraduate 11 (12.8) 2 (7.1) 4 (14.3) 5 (16.7)
Diabetes Factors, mean (SD)
Duration of diabetes, Y
5.9 (4.4)
6.3 (3.7)
6.0 (5.1)
5.4 (4.4)
Haemoglobin A1c value, % 8.2 (1.7) 8.1 (1.4) 7.6 (1.7) 8.9 (1.7)
Fasting blood sugar, mg/dl 149.1 (54.1) 142.8 (45.2) 133.8 (42.9) 169.2 (65.5)
Fasting Insulin, µIU/ml 13.3 (8.5) 15.1 (10.0) 13.5 (9.1) 11.7 (6.2)
Medications, n / (%)
Oral hypoglycaemic agents
Total
55 (64.0)
19 (67.9)
16 (57.1)
20 (66.7)
Biguanides 53 (61.6) 19 (67.9) 15 (54) 19 (63.3)
Sulfonylurea 30 (34.9) 10 (35.7) 10 (35.7) 10 (33.3)
Dipeptidyl Peptidase-4 Inhibitor C 19 (22.1) 9 (32.1) 6 (21.4) 4 (13.3)
Other 1 (1.2) 1 (3.6) 0 0
Antihypertensive agents
Total
25 (29.1)
11 (39.3)
7 (25.0)
7 (23.3)
Angiotensin II Receptor Antagonists 24 (27.9) 11 (39.3) 6 (21.4) 7 (23.3)
Other 2 (2.3) 0 2 (7.1) 0
Lipid lowering agents
Statins 27 (31.4) 11 (39.3) 9 (32.1) 7 (23.3)
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Anthropometry, mean (SD)
BMI, kg/m2
26.4 (4.0)
26.8 (4.4)
26.9 (4.7)
25.8(2.8)
Waist circumference, cm 91.3 (9.0) 91.4 (8.8) 91.6 (9.9) 91.0 (8.6)
Body fat (DXA), % 36.8(7.2) 37.0(6.4) 37.3(8.2) 36.1(7.2)
Body fat (skinfolds), % 32.7 (9.6) 34.5 (8.5) 33.2 (10.0) 30.6 (10.1)
Physical fitness, mean (SD)
Resting heart rate, bpm
90 (13)
93 (11)
89 (13)
88 (14)
Resting systolic blood pressure, mmHg 126.3(2.6) 129.0(2.8) 126.0(2.7) 123.0(2.5)
Resting diastolic blood pressure, mmHg 78.6(1.8) 79.0(1.6) 77.0(1.4) 80.0(2.2)
Strength (1RM)
Bicep curl, lbs.
20.8 (7.8)
19.3 (6.9)
21.6 (8.5)
21.4 (7.9)
Shoulder press, kg 28.2 (12.0) 25.2 (11.9) 29.2 (11.8) 29.9 (12.3)
Leg press, kg 58.0 (26.9) 51.8 (25.9) 58.3 (26.5) 63.4 (27.9) aOther – Sri Lankan Tamil and Sri Lankan Moor bOther – Unemployed (e.g. housewife), retired or student
General characteristics
Table 4.1.1 shows the participant baseline characteristics. A total of 86 participants
completed the study, of which 53% were females. The control group had more males.
Participants’ mean age was 50.1 (±8.7) years and 92% were married. All were of Sri Lankan
origin and the majority were Sinhalese ethnicity and most resided in Colombo (Capital city)
city limits and nearby suburbs. More than 85% of the participants had completed secondary
or higher education. Occupations were categorized according to International Labor
Organization categorization of occupations with the majority being house wives or retired.
The second most common category was professionals. As per the Sri Lanka Department of
Statistics, mean per capita Sri Lankan individual monthly income (2013) was Rs. 11819.00
(Urban: Rural, Rs. 17,000.00 : 10,800.00). Most of the participants’ monthly income was >
Rs.25,000.00 and >50% of those had > Rs.75,000.00 which is considered as middle-high
income level compared to Sri Lankan income standards.
Anthropometry
Most of the participants were overweight or obese according to Asian BMI cut-off values (M/
F, 29/40) with a mean BMI of 26.4 kg/m2. Most displayed central obesity and had a high
waist circumference. The % Body fat (DXA) relative to BMI for males and females were
30.2%/24.9 kgm-2: 41.5%/27.4 kg/m-2.
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Diabetes and comorbidity status
Participants were diagnosed with T2DM within last 10 years (mean 5.9 years).They were
followed up regularly in a medical/diabetic clinic under a consultant physician. Distribution
of baseline chronic glycemic state (HbA1c) and fasting glycemic state (fasting glucose/FBS
and Insulin/FI levels) showed high HbA1c and low FI in the Control group.
Medications included Metformin (Biguanide), Diamicron (Sulfonylurea) and Sitagliptin
(Dipeptidyl Peptidase-4 Inhibitor C) with Metformin prescribed the most (61.6%). Minimal
changes were made to drug administration and dosages during the intervention period of all
groups (Table 4.1.2). 29% of the participants were taking anti-hypertensives and 31.4% were
taking statins. Baseline systolic blood pressure and LDL cholesterol were controlled.
Five participants were detected with rapid abnormal elevation of blood pressure to
progressive exercise during staged exercise ECG testing/screening. They were directed to the
supervising consultant cardiologist. The reason for abnormal elevation of blood pressure
were identified as sedentary behaviour and exercise intolerance. The participants did not have
a history of other comorbidities which would act as contraindications to exercise, as they
were excluded during screening. They were instructed to continue the program.
The groups were similar in age, sex, ethnicity, duration of diabetes, medication use and
fitness levels.
Table 4.1.2 Changes to medication during intervention period
The Exercise Intervention
Table 4.1.3 summarizes the exercise training data for individuals who completed the
protocol. After the practice period participants entered the exercise program. The entry
criteria was; when participants could maintain 75 minutes of continuous exercise without any
problem (AT) and achieve 50% RM in all resistance exercises with correct technique for 3x 8
repetitions (RT). In each 75 minute session the AT group performed walking on a treadmill
(Precor USA), cycling on a stationary seated cycle (Precor USA) and stepping on a stepper
Medication Treatment
does
increased
Treatment
discontinued or
dose decreased
Both increase
and decrease in
doses
No change to
regime
Oral hypoglycemic agents
Aerobic 1 4 0 15
Resistance 0 2 1 13
Control 0 4 1 15
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alternatively; 25 minutes per each exercise. They had 2-3 minute rest in between sessions. All
achieved this exercise routine except for 3 participants who said stepping was boring and
compensated with additional minutes of cycling and walking (<15 minutes). All participants
achieved 150 minutes per week exercise dose. Heart rate was monitored intermittently
throughout each session using Polar heart rate monitors. The treadmill and cycle grade of
speed, inclination, resistance was progressively increased during the intervention. The step
speed and height were increased as the intervention progressed. The RT group completed a
circuit of 7 exercises under supervision, with 3-5 minutes rest in-between. The intensity was
increased as tolerated. Mean duration for each session was approximately 65-75 minutes.
The total exercise dose was approximately 650-700 MET/min per week for the AT and 560-
600 MET/min per week for the RT with approximate estimations made according to the
Compendium of physical activities [203].
Background physical activity was measured in the middle of the intervention (6-7 weeks) to
determine whether participants performed additional exercises apart from the intervention.
Participants wore a pedometer for continuously 7 days (total one week) except during
exercise sessions, sleeping or taking a bath. Both groups had similar daily step counts (Table
4.1.3) and they were not engaged in any organized exercise activity apart from the
intervention. The control group demonstrated a similar number of steps per day 8044
(±3892).
The intervention was planned for 24 sessions in 12 weeks / 3 months. Only 25% of the
participants could complete the sessions within 12 weeks. The average number of sessions
completed within first 12 weeks was AT/RT; 19/20. About 50% of the participants missed
two consecutive sessions and continued thereafter. Most of the time, personal and occupation
related commitments caused the non-compliance. Researchers contacted the participants via
telephone when they missed two consecutive sessions and encouraged them to continue the
program.
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Table 4.1.3 Characteristics of the exercise intervention
Characteristic
Aerobic Training
(n = 28)
Resistance Training
(n = 28)
Program characteristics
Frequency 2/week 2/week
Duration per session 75 min 65-75 min
Type Stationary cycling
Walking on a treadmill
Stepping on a stepper
Shoulder press
Lateral pull down
Biceps curl
Leg press
Leg extension
Heel lift
Abdominal crunches
starting with pelvic and
core muscle activation
Intensity 60-75% of the HRmax
Rate of Perceived exertion;
Borg scale (10-13/20 )
50-60 % RM
Progressed every 2 weeks
and as participant gained
strength
3 sets 8-10 repetitions
Equipment Precor USA, Polar USA
Warm up and cool down Warm up was a 10 minute walk on a treadmill at 50%
HRmax. Additionally, RT had dynamic stretching to major
muscle groups. Cool down was a 10 minute static
stretching routine.
MET minutes/week
(minutes) 650-700 560-600
Background physical activity
(step count per day +/- SD) 7932 (3051) 7734 (3563)
Duration to complete the
program (mean weeks) 17.1 16
Duration from last session to
post int: blood testing (days) 8.9 11.2
Sessions completed within first
3 months (out of 24 sessions) 19 20.3
Participants who missed >2
sessions in a row 15 17
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4.1 Results: Glycemic Changes
Tables 4.1.4-5 and Figures 4.1.2-6 summarizes results for baseline (pre intervention) and post
intervention change in HbA1c, Fasting blood sugar, Fasting Insulin and Homeostasis Model
Assessment-Insulin Resistance (HOMA IR) across the groups derived from a linear mixed
model analysis for repeated measures that included the covariates age and sex. Within
groups, between groups and subgroup analysis (>7.5 and <7.5 % HbA1c) are shown. The
group (p<0.05) effects were statistically significant.
Hemoglobin A1c
The absolute change in HbA1c in the Resistance training (RT) vs Control (CN) group was -
0.08% (95% CI, -0.7% to 0.8%, p= 0.87). The change in Aerobic group (AT) vs. CN was
higher but was not statistically significant 0.22% (95% CI, -0.5% to 0.9%. p=0.82). The
baseline HbA1c levels of groups were not similar, the CN group had a higher baseline value.
A subgroup analysis was conducted limited to participants with a baseline HbA1c equal or
more than 7.5%. The absolute change in HbA1c in the RT (mean HbA1c 8.8%, SE±0.2) vs.
CN (mean HbA1c 9.2%, SE±0.2) was higher than AT (mean HbA1c 8.7%, SE±0.2) vs. CN
which was 0.57%: 0.37% respectively in contrast to the total group comparison. Baseline
values of these groups were similar. There was no statistical significant change in HBA1C in
the intervention groups.
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Table 4.1.4 Changes in Hemoglobin A1c, Fasting blood sugar, Fasting Insulin
Variable
Mean (SE) Mean change (95% Confidence interval)
No. of
participants
Pre
intervention
(Baseline)
Post
intervention
(After 3
months)
Within group
Difference in
change pre and
post intervention
Intergroup
comparison
Vs Control
P value
Pairwise
Fasting blood
sugar(mg/dl)
N=86
Aerobic 28 143.7(9.5) 123.5(5.7) 20.1(0.6-39.6) -5.7(-41.2-23.3) 0.58
Resistance 28 128.2(9.3) 132.0(5.6) -3.8(-12.6-4.9) -29.6(-53.4-5.9) 0.02
Control 30 157.6(8.6) 131.8(5.6) 25.8(3.0-48.5)
Participants limited to HbA1c more than 7.5 ( n=49)
Aerobic 17 156.7(10.4) 122.5(6.5) 34.1(57.7-10.5) -2.1(-42.5-38.2) 0.9
Resistance 12 137.7(12.9) 142.7(8.1) -4.9(-15.3-25.3) -41.2(-86.9-4.4) 0.07
Control 20 174.0(9.6) 137.8(6.0) 36.2 (69.1-3.4)
Hemoglobin
A1c(%) N=86
Aerobic 28 8.1 (0.28) 7.4 (0.24) 0.74(0.24-1.25) 0.22(-0.5-0.9) 0.82
Resistance 28 7.6 (0.28) 7.0 (0.24) 0.6 (0.01-1.16) 0.08(-0.7-0.8) 0.87
Control 30 8.7 (0.28) 8.2 (0.24) 0.52 (-0.03-1.1)
Participants limited to HbA1c more than 7.5 ( n=49)
Aerobic 17 8.74 (0.2) 7.66 (0.3) 1.08(-0.4-1.7) 0.37 (-1.3-0.6) 0.4
Resistance 12 8.8 (0.3) 7.5 (0.3) 1.3(-0.2-2.4) 0.57 (-1.7-0.6) 0.3
Control 20 9.2 (0.2) 8.5 (0.2) 0.71(-0.03-1.4)
Fasting Insulin
(micIU/ml) N=86
Aerobic 28 13.8(1.42) 14.0(1.4) -0.25(-2.4-2.9) -2.8(-0.58-6.2) 0.1
Resistance 28 13.3(1.5) 13.5(1.47) -0.2 (-2.5-2.9) -2.8(-0.58-6.3) 0.1
Control 30 11.6(1.39) 14.7(1.38) -3.0 (0.8-5.3)
Participants limited to HbA1c more than 7.5 ( n=49)
Aerobic 17 13.7 (1.4) 13.3(1.6) 0.4(-2.8-2.0) 3.6(0.2-7.1) 0.04
Resistance 12 11.2 (1.7) 12.9 (2.1) -1.7(-1.9-5.3) 1.5(-2.7-5.8) 0.4
Control 20 11.3 (1.2) 14.5 (1.4) -3.2(0.6-5.8)
HOMA-IR N=86
Aerobic 28 1.95 (0.2) 1.92(0.19) 0.02(-0.42-0.36) 0.33(-0.2-0.8) 0.2
Resistance 28 1.81(0.21) 1.90 (0.2) -0.09(-0.30-0.48) 0.21(-0.3-0.7) 0.4
Control 30 1.74 (0.19) 2.0 (0.19) -0.3(-0.06-0.67)
Participants limited to HbA1c more than 7.5 ( n=49)
Aerobic 17 1.98(0.20) 1.81(0.22) 0.16(-0.51-0.18) 0.46(-0.1-1.0) 0.1
Resistance 12 1.58(0.26) 1.86(0.29) -0.27(-0.26-0.81) 0.03(-0.7-0.7) 0.9
Control 20 1.73 (0.18) 2.0 (0.2) -0.3 (-0.13-0.7)
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4.1.5 Directional changes of variables
Group Outcome measures
HBA1c FBS Fasting Insulin
Total group (N=86)
Aerobic Reduced most Reduced Increased
Resistance Reduced Sig increased Increased
Control Reduced Reduced Sig increased
Participants limited to HbA1c more than 7.5 ( n=49)
Aerobic Reduced Reduced most Reduced
Resistance Reduced most Increased Increased
Control Reduced Reduced Increased
Participants limited to HbA1c less than 7.5 ( n=37)
Aerobic Reduced Increased most Increased
Resistance Reduced Increased Reduced
Control Increased No change Increased
Figure 4.1.2 (a) Mean changes in HbA1c
7
7.2
7.4
7.6
7.8
8
8.2
8.4
8.6
8.8
9
Pre Post
Mea
n c
han
ge in
Hb
A1
c %
Aerobic
Resistance
Control
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87
Figure 4.1.2 (b) Mean changes in HbA1c in participants with HbA1c < 7.5%
Figure 4.1.2 (c) Mean changes in HbA1c in participants with HbA1c > 7.5%
6.6
6.65
6.7
6.75
6.8
6.85
6.9
Pre Post
Mea
n C
han
ge in
Hb
A1
c %
Aerobic
Resistance
Control
7.4
7.9
8.4
8.9
9.4
Pre Post
Mea
n C
han
ge in
Hb
A1
c %
Aerobic
Resistance
Control
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Figure 4.1.3 Individual profiles of changes in HbA1c
Fasting blood sugar (FBS)
Change in fasting blood sugar levels showed a different picture. In within group analysis RT
group did not improve FBS (3.8 mg/dl, 95% CI, -4.9 to 12.6), whereas in AT and CN, it
reduced. The absolute change in FBS in the CN group improved better compared to
intervention groups. Between RT vs. CN, the RT significantly increased FBS compared to
control (29.6 mg/dl, 95% CI, 53.4 to 5.9 mg/dl). In the subgroup analysis of poorly controlled
(baseline more than 7.5% HbA1c), the outcome was the same.
-3
-2
-1
0
1
2
3
4
MEA
N C
HA
NG
E IN
HB
A1
C
INTERVENTION GROUP PARTICIPANTS(N)
Control Resistance Aerobic
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Figure 4.1.4 (a) Mean changes in FBS
Figure 4.1.4 (b) Mean change in FBS in participants with HbA1c < 7.5%
120
125
130
135
140
145
150
155
160
165
170
Pre Post
Mea
n c
han
ge in
FB
S (m
g/d
l)
Aerobic
Resistance
Control
105
110
115
120
125
130
Pre Post
Mea
n c
han
ge in
FB
S (m
g/d
l)
Aerobic
Resistance
Control
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90
Figure 4.1.4 (c) Mean changes in FBS in participants with HbA1c > 7.5%
Fasting Insulin (FI)
The post intervention mean Fasting Insulin (FI) levels increased in all 3 groups. The increase
of FI in CN group was the highest 3.0 micIU/ml (95% CI, 0.8 to 5.3 micIU/ml) compared to
AT and RT which were very mild. (p<0.1). In subgroups analysis (>7.5 % HbA1c) AT group
reduced the FI levels, whereas RT and CN increased. The AT group reduced FI levels
significantly compared to CN (3.6 micIU/ml, 95% CI, 0.2 to7.1 micIU/ml, p=0.04).
120
130
140
150
160
170
180
Pre Post
Mea
n c
han
ge in
FB
S (m
g/d
l)
Aerobic
Resistance
Control
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Figure 4.1.5 (a) Mean changes in FI
Figure 4.1.5 (b) Mean changes in FI in participants with HbA1c < 7.5%
11
11.5
12
12.5
13
13.5
14
14.5
15
Pre Post
Mea
n c
han
ge in
FI (
mic
IU/m
l)
Aerobic
Resistance
Control
13
13.5
14
14.5
15
15.5
16
Pre Post
Mea
n c
han
ge in
FI (
mic
IU/m
l)
Aerobic
Resistance
Control
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92
Figure 4.1.5 (c) Mean changes in FI in participants with HbA1c > 7.5%
Homeostasis Model Assessment-Insulin Resistance (HOMA- IR)
It should be recognized that HOMA is a measure of basal insulin sensitivity and beta cell
function. In contrast to glucose clamp techniques, is not intended to give information about
the stimulated state. The equation (HOMA-IR FBS x FI /22.5) developed for calculation
shows that it is influences by FBS and FI levels .HOMA IR (insulin resistance) equations
have been used widely, particularly for estimates of beta cell function and insulin resistance
in large-scale studies, but are not appropriate for use with currently available insulin assays.
It provides the magnitude and direction of the insulin resistance state. The changes were
similar to FI changes. IR increased in the total and sub groups in the CN, possibly due to the
disease progression though the HbA1c had reduced. Interestingly, the RT improved IR at
lower glycemic state and increased in the higher glycemic state. The AT response was in the
opposite direction to the RT.
11
11.5
12
12.5
13
13.5
14
14.5
15
Pre Post
Mea
n c
han
ge in
FI (
mic
IU/m
l)
Aerobic
Resistance
Control
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93
Figure 4.1.6 (a) Mean change in HOMA-IR
Figure 4.1.6 (b) Mean changes in HOMA-IR in participants with HbA1c < 7.5%
1.7
1.75
1.8
1.85
1.9
1.95
2
2.05
2.1
Pre Post
Mea
n c
han
ge in
HO
MA
-IR
Aerobic
Resistance
Control
1.7
1.8
1.9
2
2.1
2.2
Pre Post
Mea
n c
han
ge in
HO
MA
-IR
Aerobic
Resistance
Control
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94
Figure 4.1.6 (c) Mean changes in HOMA-IR in participants with HbA1c > 7.5%
1.5
1.6
1.7
1.8
1.9
2
2.1
Pre Post
Mea
n c
han
ge in
HO
MA
-IR
Aerobic
Resistance
Control
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4.2 Results: Adiposity and anthropometrics
Baseline anthropometry and body composition of participants
The mean weight of the SL-DARTS population was 67.7 kg (SD ± 11.2; M/ F:70.4/65.9 kg),
mean height 1.6 m (SD ± 0.2; M/ F: 1.7/1.5 m) and mean BMI 26.4 kg/m2 (SD ± 4.1; M/ F:
24.9/27.5 kg/m2).
According to Asian BMI cut-off values of ≥23–24.9 kg/m2 and ≥25 kg/m2 for overweight
and obesity, respectively, 16% of the participants were overweight (n=14, M:F 8:6), and 60%
were obese (n=45, M:F 11:34). The mean waist circumference was 91.4 cm (SD ±9.0; M/F:
92.4/90.7 cm). The majority of the females (93%) had waist circumference (WC) values >80
cm and 58% of the males had WC >90 cm with the tendency of central obesity. The mean
mid-arm circumference was 30.5 cm (SD ± 3.2; M/F: 30.1/30.8 cm) and mid-thigh
circumference was 49.5 cm (SD ± 5.5; M/F: 48.7/50.1 cm).
The mean % body fat (DXA) relative to mean BMI for all males and females were
30.2%/25.0 kgm-2: 41.5%/27.4 kg/m-2. The overweight and obese female participants had a
higher mean % BF (Overweight M/F: 29.7: 41.8%; Obese; .M/F, 32.7:42.7) and most of them
were centrally obese. For a similar BMI value; females had >10% body fat higher compared
to males. The mean difference of the absolute value between the baseline %BF measured by
the skin fold method and DXA results was 3.9% (SD ± 5.6%).
In the group wise comparison, BMI and WC were distributed equally. Control group
participants had lower body weight, % body fat and fat mass.
Group comparisons
Table 4.2.1 summarizes results for baseline (pre intervention) and post intervention changes
in body weight, body mass index (BMI), girths/ circumferences (waist, hip, mid-arm, mid-
thigh), %body fat (by DXA scan and skin fold measurements) and total fat mass by DXA
across the groups, derived from a linear mixed model analysis for repeated measures that
included the covariates age, and sex. Within groups, between control and intervention group
analyses are shown. The group (p<0.05) effects were statistically significant.
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Table 4.2.1 Changes in anthropometrics and body composition
Mean (SE),% Mean change (95% Confidence interval)
Variable No of
participants
Pre
intervention
Baseline
Post
intervention
After 3
months
Within group
Difference in
change pre and
post intervention
Intergroup
comparison
vs. Control
P value
Pairwise
Body weight (kg) N=86
Aerobic 28 67.0 (2.5) 66.9(2.5) 0.08(-1.0-0.7) 0.6(-0.3-1.6) 0.2
Resistance 28 69.7(2.3) 69.6(2.4) 0.06(-0.7-0.9) 0.6(-0.4-1.6) 0.2
Control 30 65.4 (2.5) 65.9(2.5) -0.6(-0.9-0.5)
Height (m) N=86
Aerobic 28 1.59(0.2) 1.59(0.2) 0.00(0.00) 0.00(0.00) -
Resistance 28 1.61(0.2) 1.61(0.2) 0.00(0.00) 0.00(0.00) -
Control 30 1.59(0.2) 1.59(0.2) 0.00(0.00) 0.00(0.00)
BMI (kg/m2) N=86
Aerobic 28 26.77(0.8) 26.79(0.8) 0.02 (-0.3-0.3) 0.12(-0.3-0.5) 0.6
Resistance 28 26.86 (0.8) 26.85(0.8) 0.01 (-0.3-0.3) 0.14(-0.3-0.5) 0.5
Control 30 25.85(0.8) 26.0 (0.8) -0.13 (-0.4-0.1)
WC (cm) N=86
Aerobic 28 91.4 (1.8) 90.0(1.9) 1.3(0.01-2.6) 0.5(-1.4-2.5) 0.6
Resistance 28 91.6 (1.9) 89.6 (2.0) 2.0 (0.3-3.7) 1.2(-1.0-3.5) 0.2
Control 30 91.2 (1.9) 90.4 (2.0) 0.8 (-0.7-2.3)
Mid-arm C (cm) N=86
Aerobic 28 30.4(0.6) 29.5(0.6) 0.9(0.4-1.3) 0.3(-0.3-0.9) 0.3
Resistance 28 30.8(0.6) 30.3(0.6) 0.5(0.01-1.1) -0.06(-0.8-0.6) 0.8
Control 30 30.4(0.6) 29.8(0.6) 0.6(0.1-1.1)
Mid-thigh C (cm) N=86
Aerobic 28 49.4(1.1) 49.0(1.0) 0.4(-0.4-1.1) -0.3(-1.3-0.6) 0.5
Resistance 28 51.1(1.1) 50.3(1.0) 0.8(-0.6-2.2) 0.1(-1.4-1.5) 0.9
Control 30 48.9(1.1) 48.2(1.0) 0.7(0.1-1.3)
%BF DXA N=82
Aerobic 26 36.8(1.5) 36.2(1.4) 0.54(0.0-1.7) 0.5(-0.5-1.4) 0.3
Resistance 27 37.3(1.5) 37.1(1.4) 0.11(-0.5-0.7) 0.06(-0.8-1.0) 0.9
Control 29 36.0 (1.6) 35.9(1.5) 0.04(-0.8-0.8)
Fat mass (kg) N=82
Aerobic 26 24.659(1.5) 24.264(1.5) 0.395(-0.1-1.0) 0.562(-0.4-1.5) 0.2
Resistance 27 25.632(1.4) 25.485(1.4) 0.147 (-0.5-0.8) 0.314(-0.6-1.2) 0.5
Control 29 23.161(1.5) 23.328(1.5) -0.166(-1.0-0.6)
%BF Skin Folds N=86
Aerobic 28 34.5(1.9) 32.6(1.8) 1.8(1.1-2.5) 1.7(0.5-2.7) 0.004
Resistance 28 33.2(1.9) 32.2(1.8) 1.0(0.06-1.9) 0.9(-0.4-2.1) 0.2
Control 29 32.2(1.9) 32.1(1.8) 0.1(-0.7-1.0)
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97
Body weight and BMI
Change in mean absolute weight (and BMI) was minimal among groups, with a small
elevation of weight in the CN (Figures 4.2.1 (a), (b)). Figure 4.2.2 details changes in body
weight for individual participants. The overall mean effect was insignificant.
Figure 4.2.1. (a) Means changes in body weight
65
65.5
66
66.5
67
67.5
68
68.5
69
69.5
70
Pre Post
Mea
n c
han
ge in
Bo
dy
wei
ght
(kg)
Aerobic
Resistance
Control
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98
Figure 4.2.1. (b) Mean changes in BMI
Figure 4.2.2 Individual profiles of changes in body weight
25.8
26
26.2
26.4
26.6
26.8
27
Pre Post
Mea
n c
han
ge in
BM
I (kg
.m2 )
Aerobic
Resistance
Control
-6
-4
-2
0
2
4
6
MEA
N C
HA
NG
E IN
BO
DY
WEI
GH
T (K
G)
INTERVENTION GROUP PARTICIPANTS
Control Resistance Aerobic
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99
Girths and circumferences
Table 4.2.2 summarizes results and Figures 4.2.3 (a) to (e), shows the trends for changes in
body girths/circumferences (waist, hip, mid-arm, mid-thigh). There was a reduction in
absolute mean WC in all three groups where RT reduced the most (RT>AT) compared to
controls. Hip circumference (HC) also showed a similar trend. The RT group had a higher
baseline mean HC value compared to others accounting for a lower waist-to-hip ratio.
The mean absolute arm circumference was reduced among groups where AT showed the
most marked reduction. The mid-thigh circumferences also reduced post intervention,
however, the reduction was lower among the AT group.
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Table 4.2.2 Changes in body girths and circumferences
Mean (SE),% Mean (95% Confidence interval)
Variable No of
participants
Pre
intervention
Baseline
Post
intervention
After 3
months
Within group
Difference in
change pre and
post intervention
Intergroup
comparison
Vs Control
P value
Pairwise
BMI(kg/m2) N=86
Aerobic 28 26.77(0.8) 26.79(0.8) 0.02 (-0.3-0.3) 0.12(-0.3-0.5) 0.6
Resistance 28 26.86 (0.8) 26.85(0.8) 0.01 (-0.3-0.3) 0.14(-0.3-0.5) 0.5
Control 30 25.85(0.8) 26.0 (0.8) -0.13 (-0.4-0.1)
Height (m) N=86
Aerobic 28 1.59(0.2) 1.59(0.2) 0.00(0.00) 0.00(0.00) -
Resistance 28 1.61(0.2) 1.61(0.2) 0.00(0.00) 0.00(0.00) -
Control 30 1.59(0.2) 1.59(0.2) 0.00(0.00) 0.00(0.00)
WC (cm) N=86
Aerobic 28 91.4(1.8) 90.0(1.9) 1.3(0.01-2.6) 0.5(-1.4-2.5) 0.6
Resistance 28 91.6(1.9) 89.6 (2.0) 2.0(0.3-3.7) 1.2(-1.0-3.5) 0.2
Control 30 91.2(1.9) 90.4 (2.0) 0.8(-0.7-2.3)
HC (cm) N=86
Aerobic 28 96.9(1.8) 95.3(1.8) 1.6(-.04-3.6) 1.1(-1.0-3.2) 0.3
Resistance 28 99.8(1.8) 98.2 (1.8) 1.6(0.3-3.0) 1.1(-0.5-2.6) 0.2
Control 30 94.7(1.8) 94.2(1.8) 0.5(-0.4-1.4)
W:H N=86
Aerobic 28 0.95(0.01) 0.95(0.01) 0.00(0.00) 0.00(0.00) 1.0
Resistance 28 0.92(0.01) 0.91(0.01) 0.01(-0.01-0.02) 0.01(-0.01-0.02) 0.8
Control 30 0.96(0.01) 0.96 (0.01) 0.00(0.00)
Mid-arm C (cm) N=86
Aerobic 28 30.4(0.6) 29.5(0.6) 0.9(0.4-1.3) 0.3(-0.3-0.9) 0.3
Resistance 28 30.8(0.6) 30.3(0.6) 0.5(0.01-1.1) -0.06(-0.8-0.6) 0.8
Control 30 30.4(0.6) 29.8(0.6) 0.6(0.1-1.1)
Mid-thigh C (cm) N=86
Aerobic 28 49.4(1.1) 49.0(1.0) 0.4(-0.4-1.1) -0.3(-1.3-0.6) 0.5
Resistance 28 51.1(1.1) 50.3(1.0) 0.8(-0.6-2.2) 0.1(-1.4-1.5) 0.9
Control 30 48.9(1.1) 48.2(1.0) 0.7(0.1-1.3)
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101
Figure 4.2.3. (a) Mean changes in Waist Circumference
Figure 4.2.3. (b) Mean changes in Hip Circumference
89.5
90
90.5
91
91.5
92
Pre Post
Mea
n c
han
ge in
WC
(cm
)
Aerobic
Resistance
Control
94
95
96
97
98
99
100
Pre Post
Mea
n c
han
ge in
HC
(cm
)
Aerobic
Resistance
Control
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102
Figure 4.2.3. (c) Mean changes in Waist: Hip ratios
Figure 4.2.3. (d) Mean changes in Mid-Arm Circumference
0.91
0.92
0.93
0.94
0.95
0.96
0.97
Pre Post
Mea
n c
han
ge in
W:H
Aerobic
Resistance
Control
29.5
29.7
29.9
30.1
30.3
30.5
30.7
30.9
Pre Post
Mea
n c
han
ge in
MA
C (
cm)
Aerobic
Resistance
Control
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103
Figure 4.2.3. (e) Mean changes in Mid-Thigh Circumference
Body composition
Table 4.2.3 and Figures 4.2.4 (a) to (d) summarizes results for body composition measured
by DXA and skin fold thickness (SF) calculation method. A reduction in absolute mean
%body fat was seen among intervention groups where AT showed a marked reduction as
assessed by both techniques (statistically significant change from SF) compared to the control
group. The mean total fat mass by DXA showed a reduction among intervention groups (AT
> RT, p>0.05) while CN group gained the total fat mass with no statistical significance.
Figure 4.2.5 details changes in total fat mass for individual participants.
48
48.5
49
49.5
50
50.5
51
51.5
52
Pre Post
Mea
n c
han
ge in
MTC
(cm
)
Aerobic
Resistance
Control
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Table 4.2.3 Changes in body composition measured by DXA
Mean (SE),% Mean (95% Confidence interval)
Variable No of
participants
Pre
intervention
Baseline
Post
intervention
After 3
months
Within group
Difference in
change pre and
post intervention
Intergroup
comparison
Vs Control
P value
Pairwise
%BF DXA N=82
Aerobic 26 36.8(1.5) 36.2(1.4) 0.54(0.0-1.7) 0.5(-0.5-1.4) 0.3
Resistance 27 37.3(1.5) 37.1(1.4) 0.11(-0.5-0.7) 0.06(-0.8-1.0) 0.9
Control 29 36.0 (1.6) 35.9(1.5) 0.04(-0.8-0.8)
Fat mass (kg) N=82
Aerobic 26 24.659(1.5) 24.264(1.5) 0.395(-0.1-1.0) 0.562(-0.4-1.5) 0.2
Resistance 27 25.632(1.4) 25.485(1.4) 0.147 (-0.5-0.8) 0.314(-0.6-1.2) 0.5
Control 29 23.161(1.5) 23.328(1.5) -0.166(-1.0-0.6)
Fat free mass(kg) N=82
Aerobic 26 38.875(1.6) 39.026(1.6) -0.150(-0.8-0.4) 0.008(-0.6-0.4) 0.8
Resistance 27 40.969(1.6) 41.063(1.6) -0.094(-0.4-0.3) 0.063(-0.6-0.7) 0.7
Control 29 38.678(1.6) 38.837(1.6) -0.158(-0.8-0.5)
L Arm(kg) N=82
Aerobic 26 1.475(0.1) 1.451(0.1) 0.24(-0.06-0.14) 0.043 (-0.1-0.1) 0.5
Resistance 27 1.590(0.1) 1.585(0.1) 0.005(-0.07-0.07) 0.024(-0.1-0.1) 0.6
Control 29 1.334(0.1) 1.353(0.1) -0.019(-0.09-0.12)
R Arm(kg) N=82
Aerobic 26 1.459(0.1) 1.489(0.1) 0.029 (-0.1-0.1) 0.023 (-0.1-0.1) 0.6
Resistance 27 1.582(0.1) 1.550(0.1) 0.032 (-0.1-0.1) 0.039 (-0.1-0.2) 0.5
Control 29 1.392(0.1) 1.399(0.1) - 0.007(-0.1-0.1)
L Leg (kg) N=82
Aerobic 26 3.743(0.3) 3.703(0.3) 0.040(-0.1-0.2) 0.020(0.01-0.1) 0.8
Resistance 27 4.053(0.3) 4.024(0.2) 0.028(-0.1-0.1) 0.008 (-0.1-0.2) 0.9
Control 29 3.414(0.3) 3.394(0.3) 0.020(-0.1-0.1)
R Leg (kg) N=82
Aerobic 26 3.861(0.3) 3.753(0.3) 0.108(-0.02-0.2) 0.075(-0.1-0.2) 0.4
Resistance 27 4.189(0.3) 4.159(0.2) 0.030(-0.1-0.1) -0.004(-0.2-0.2) 0.9
Control 29 3.593(0.3) 3.559(0.3) 0.034(-0.1-0.2)
Trunk (kg) N=82
Aerobic 26 13.019(0.8) 12.761(0.8) 0.257(-0.2-0.7) 0.456(-0.2-1.1) 0.2
Resistance 27 13.122(0.7) 13.065(0.7) 0.057(-0.4-0.4) 0.255(0.2-0.3) 0.4
Control 29 12.339(0.8) 12.538(0.8) -0.199(-0.6-0.2)
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105
Figure 4.2.4. (a) Mean changes in % total body fat by DXA
Figure 4.2.4. (b) Mean changes in % total body fat by skin fold thickness
35.5
35.7
35.9
36.1
36.3
36.5
36.7
36.9
37.1
37.3
37.5
Pre Post
Mea
n c
han
ge in
%B
F (D
XA
)
Aerobic
Resistance
Control
32
32.5
33
33.5
34
34.5
Pre Post
Mea
n c
han
ge in
%B
F (S
F)
Aerobic
Resistance
Control
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106
Figure 4.2.4. (c) Mean changes in fat mass by DXA
Figure 4.2.4. (d) Mean changes in Fat Free Mass by DXA
23
23.5
24
24.5
25
25.5
26
Pre Post
Mea
n c
han
ge in
Fat
mas
s (k
g)
Aerobic
Resistance
Control
38.5
39
39.5
40
40.5
41
41.5
Pre Post
Mea
n c
han
ge in
Fat
Fre
e M
ass
(kg)
Aerobic
Resistance
Control
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107
Figure 4.2.5 Individual profile of changes in total body fat mass (DXA)
Regional body composition
Regional changes in skin fold thickness are detailed in Table 4.2.4 and Figures 4.2.6 (a) to
(g). There was a reduction in mean absolute skin fold thickness in all seven sites in both
intervention groups with greater reductions in the AT compared to RT at all sites except the
chest and mid-thigh. Most of these changes reached statistical significance compared to the
absolute mean skinfold thickness values of the CN. The reduction in mid-thigh was
statistically significant in both groups (RT>AT). There was an increase in chest, scapular and
suprailliac regions in the CN.
The changes in fat mass assessed by DXA (Table 4.2.3) showed higher fat mass loss in the
intervention groups (AT>RT) compared to CN, with changes in trunk and leg values marked.
-3
-2
-1
0
1
2
3
4
Mm
ean
ch
ange
in t
ota
l fat
mas
s (k
g)
INDIVIDUAL PARTICIPANTS
Control Resistance Aerobic
Page 125
108
Figure 4.2.6. (a) Mean changes in triceps skin fold thickness
Figure 4.2.6. (b) Mean changes in chest skin fold thickness
22
22.5
23
23.5
24
24.5
25
25.5
26
26.5
27
Pre Post
Mea
n c
han
ge in
Tri
cep
s SF
(m
m)
Aerobic
Resistance
Control
23.5
24
24.5
25
25.5
26
26.5
Pre Post
Mea
n c
han
ge in
Ch
est
SF (
mm
)
Aerobic
Resistance
Control
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109
Figure 4.2.6. (c) Mean changes in axillary skin fold thickness
Figure 4.2.6. (d) Mean changes in scapular skin fold thickness
27
28
29
30
31
32
33
Pre Post
Mea
n c
han
ge in
Axi
llary
SF
(mm
)
Aerobic
Resistance
Control
32
33
34
35
36
37
38
Pre Post
Mea
n c
han
ge in
Sca
pu
lar
SF (
mm
)
Aerobic
Resistance
Control
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110
Figure 4.2.6. (e) Mean changes in abdominal skin fold thickness
Figure 4.2.6. (f) Mean changes in supra iliac skin fold thickness
35.5
36.5
37.5
38.5
39.5
40.5
41.5
42.5
Pre Post
Mea
n c
han
ge in
Ab
do
min
al S
F (m
m)
Aerobic
Resistance
Control
22
22.5
23
23.5
24
24.5
25
25.5
Pre Post
Mea
n c
han
ge in
Su
pra
iliac
SF
(mm
)
Aerobic
Resistance
Control
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111
Figure 4.2.6. (g) Mean changes in thigh skin fold thickness
24
25
26
27
28
29
30
31
32
Pre Post
Mea
n c
han
ge in
Th
igh
SF
(mm
)
Aerobic
Resistance
Control
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112
Table 4.2.4 Changes in body composition measured by 7 site skin fold thickness
calculation (ACSM)
Mean (SE),% Mean change (95% Confidence interval)
Variable No of
participants
Pre
intervention
Baseline
Post
intervention
After 3
months
Within group
Difference in
change pre and
post intervention
Intergroup
comparison
Vs Control
P value
Pairwise
%BF Skin folds N=85
Aerobic 28 34.5(1.9) 32.6(1.8) 1.8(1.1-2.5) 1.7(0.5-2.7) 0.004
Resistance 28 33.2(1.9) 32.2(1.8) 1.0(0.06-1.9) 0.9(-0.4-2.1) 0.2
Control 29 32.2(1.9) 32.1(1.8) 0.1(-0.7-1.0)
Triceps (mm) N=85
Aerobic 28 25.3(1.9) 22.7(1.9) 2.6 (1.1-4.1) 1.7(-0.6-4.1) 0.1
Resistance 28 26.3(1.9) 24.8(1.9) 1.5(-0.3-3.4) 0.6(-2.0-3.2) 0.6
Control 29 23.9(1.9) 23.0(1.9) 0.9(-1.1-2.8)
Chest (mm) N=85
Aerobic 28 26.1(1.8) 25.6(1.8) 0.4(-1.4-2.1) 1.3(-0.9-3.5) 0.2
Resistance 28 26.0(1.8) 25.2(1.8) 0.8(-0.5-2.1) 1.8(0.1-3.6) 0.05
Control 29 23.7(1.8) 24.6(1.8) -0.9(-2.3-0.4)
Mid Axilla (mm) N=85
Aerobic 28 32.1(2.0) 28.6(1.8) 3.4(1.6-5.2) 3.3(0.04-6.6) 0.04
Resistance 28 29.7(2.0) 27.3(1.8) 2.4((0.2-4.6) 2.3(-1.2-5.8) 0.2
Control 29 29.7(2.0) 29.6(1.8) 0.1(-2.7-2.9)
Subscapular (mm) N=85
Aerobic 28 37.4(2.3) 34.8(2.1) 2.6(0.2-5.0) 3.2(0.3-6.8) 0.05
Resistance 28 33.0(2.3) 33.0(2.0) 0.02(-2.7-2.8) 0.7(-3.2-4.5) 0.7
Control 29 35.0(2.3) 35.6(2.1) -0.6(-3.4-2.1)
Abdomen (mm) N=85
Aerobic 28 41.7(2.8) 38.0(2.5) 3.7(1.5-5.8) 2.2(-1.1-5.5) 0.2
Resistance 28 40.8(2.8) 37.8(2.6) 2.9(-0.6-6.5) 1.4(-2.8-5.7) 0.5
Control 29 37.1(2.8) 35.6(2.5) 1.4(-1.2-4.1)
Mid-thigh (mm) N=85
Aerobic 28 27.9(2.8) 24.8(2.5) 3.0(0.9-5.1) 3.0(0.2-5.7) 0.03
Resistance 28 31.0(2.8) 27.3(2.6) 3.7(1.3-6.0) 3.7(0.8-6.6) 0.01
Control 29 26.2(2.8) 26.2(2.6) 0.00(0.00)
Supraillic (mm) N=85
Aerobic 28 25.1(1.9) 22.3(1.8) 2.7(0.9-4.5) 3.0(0.2-5.7) 0.03
Resistance 28 25.1(1.9) 23.4(1.8) 1.7(-0.9-4.2) 1.9(-1.3-5.1) 0.2
Control 29 23.5(1.9) 23.7(1.8) -0.2(-2.4-1.9)
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113
Comparison of regional anthropometry and body composition with different methods
In this population, changes in fat depots, fat mass and circumferences measured were focused
on the mid arm, mid-thigh and trunk (upper and lower) regions, as illustrated in Table 4.2.5.
Both intervention groups showed reductions in mid-arm circumference (MAC) and the
thickness in the triceps fat depots (AT > RT). For MAC there was a greater change in the AT
compared to RT. Fat mass reduced in both groups; but not significantly.
In the thighs, absolute mid-thigh circumference (MTC) reduced in both groups with a
significant reduction in mid-thigh skin fold values (RT > AT). In the legs, fat mass reduced
more in the AT group.
In the upper body, waist circumference reduced more in RT (RT > AT) whereas, the skin fold
thicknesses reduced more in the AT (abdomen and supra iliac regions). In the upper trunk,
AT reduced skin folds significantly in the mid axilla and subscapular regions, and RT in the
chest region.
Table 4.2.5 Comparison in regional body composition with different methods
Region/ Group
Absolute mean change (95% Confidence interval) compared to control group
Girths (cm) Skin folds thickness values (mm) Fat mass-DXA Scan (kg)
Arm
Mid-arm Triceps Right arm Left arm
Aerobic 0.3(-0.3-0.9) 1.7(-0.6-4.1) 0.023 (-0.1-0.1) 0.043 (-0.1-0.1)
Resistance -0.06(-0.8-0.6) 0.6(-2.0-3.2) 0.039 (-0.1-0.2) 0.024(-0.1-0.1)
Thigh/leg
Mid-thigh Hip Mid-Thigh Right leg Left leg
Aerobic -0.3(-1.3-0.6) 1.1(-1.0-3.2) 3.0(0.2-5.7) 0.075(-0.1-0.2) 0.020(0.01-0.1)
Resistance 0.1(-1.4-1.5) 1.1(-0.5-2.6) 3.7(0.8-6.6) -0.004(-0.2-0.2) 0.008 (-0.1-0.2)
Lower trunk
WC Abdomen Supra illiac Trunk
Aerobic 0.5(-1.4-2.5) 2.2(-1.1-5.5) 3.0(0.2-5.7) 0.456(-0.2-1.1)
Resistance 1.2(-1.0-3.5) 1.4(-2.8-5.7) 1.9(-1.3-5.1) 0.255(0.2-0.3)
Upper trunk Mid Axilla Subscapular Chest
Aerobic 3.3(0.04-6.6) 3.2(0.3-6.8) 1.3(-0.9-3.5)
Resistance 2.3(-1.2-5.8) 0.7(-3.2-4.5) 1.8(0.1-3.6)
Bold values: Statistically significant changes when compared with CN
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4.3 Results: Metabolic Parameters
Table 4.3.1 and Figures 4.3.1 (a) to (d), 4.3.2 (a, b), 4.3.3, summarizes results for pre and post
intervention change in the metabolic components; lipid profile, liver enzymes (AST/ALT)
and inflammatory marker (highly sensitive C reactive protein) derived from a linear mixed
model analysis for repeated measures included the covariates age and sex. Within and
between group analysis are shown. The group (p < 0.05) effects were statistically significant.
Baseline
Baseline mean values across Aerobic (AT), Resistance (RT) and Control (CN) groups were
similar in High Density Lipoprotein / HDL, Serum Aspartate aminotransferase / AST and
highly sensitive serum C - reactive protein / hs-CRP levels. In other parameters baseline of
lipid profile (Total cholesterol / TC, Low Density Lipoprotein / LDL, Triglycerides / TG),
Alanine aminotransferase / ALT were different.
Lipid profile
The baseline levels of lipid profile was within clinically normal ranges. The lipid levels were
controlled. The SL-DARTS population were on long term statins / lipid lowering drugs
(Stains: N=27 (31.4%), AT; n=11 (39.3%), RT; n=9 (32.1%), CN; n=7 (23.3%)) which did
not change during the intervention period. The AT group reduced TC, HDL, LDL and
increased TG levels. These changes were not statistically significant and very trivial
compared to the similar changes in the control. RT showed increase in all parameters where
in TC, HDL and LDL showed a significant increase compared to control.
Live enzymes
Baseline liver enzyme levels were higher than clinically normal values (ALT > AST). All 3
groups reduced the AST levels (RT>CN>AT). The ALT levels changed minimally in the RT,
where it reduced in the CN and AT. The reduction in AT was less compared to CN.
Inflammatory marker: hs-CRP
Baseline mean hs-CRP was 3.2 mg/L were 37% were at high risk category (3–10 mg/L) with
more in the control group (AT/RT/CN; 32/28/48 %). The hs-CRP levels reduced in both
intervention and control groups. The interventional groups’ reduction was more than the
control.
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115
Table 4.3.1 Changes in Lipid profile, Liver enzymes, and hs-CRP
Variable
Mean (SE)% Mean Change (95% Confidence interval)
No of
participants
Pre
intervention
(Baseline)
Post
intervention
(After 3
months)
Within group
Difference in
change pre and
post intervention
Intergroup
comparison
Vs Control
P value
Pairwise
Total
cholesterol(mg/dl)
N=82
Aerobic 26 167.5(7.8) 167.2(7.2) 0.2(-14.8-15.4) -6.7(-31.0-17.7) 0.6
Resistance 27 155.0(7.7) 175.0 (7.1) -25.4 (-53.4-1.4) -27.6(-53.4-5.9) 0.04
Control 28 184.2 (8.6) 177.3 (5.6) 6.9(-12.8-26.7)
HDL (mg/dl) N=82
Aerobic 26 51.4(2.2) 49.7 (2.6) 1.74 (-3.9-7.2) -1.8(-7.5-3.8) 0.5
Resistance 27 49.0(2.2) 49.4 (2.6) -0.4 (-3.5-2.8) -3.9(-7.6-(-0.7)) 0.04
Control 28 49.2(2.2) 45.7 (2.6) 3.5 (1.4-5.5)
LDL (mg/dl) N=82
Aerobic 26 93.8(7.1) 92.9(6.5) 0.9(-13.5-15.3) -4.1(-0.58-6.2) 0.7
Resistance 27 84.5(7.0) 103.9(6.4) -19.4 (-35.7-3.1) -24.4(-47.8-1.1) 0.04
Control 28 108.4(7.0) 103.4 (6.4) 5.0 (-12.5-22.5)
Triglycerides
(mg/dl)
N=82
Aerobic 26 108.9 (10.1) 114.4 (15.5) -5.4 (-28.9-18.1) 11.1(-24-46.) 0.5
Resistance 27 106.1(9.9) 109.0 (15.2) -2.9 (-23.8-17.9) 13.6(-19.7-47) 0.4
Control 28 134.2 (9.9) 150.8 (15.2) -16.5 (-43.7-10.7)
AST (u/l) N=86
Aerobic 28 37.4(2.6) 36.5(2.6) 0.8(-4.7-6.3) -2.2(-9.4-5.0) 0.5
Resistance 28 32.4(2.6) 26.8(2.6) 5.6(1.0-10.0) 2.5(-3.9-9.9) 0.4
Control 30 33.9(2.6) 30.9(2.6) 3.0(-1.9-7.9)
ALT (u/l) N=86
Aerobic 28 57.8(5.1) 55.9(4.6) 1.8(-7.1-10.8) -3.4(-14.7-8.0) 0.5
Resistance 28 45.8(5.1) 46.2(4.6) -0.4(-8.0-7.3) -5.6(-16.1-4.9) 0.3
Control 30 58.7(5.1) 53.5(4.6) 5.2(-2.3-12.8)
Hs-CRP (mg/L) N=79
Aerobic 26 2.7(0.7) 2.4(0.6) 0.3(-0.9-0.8) 0.2(-2.0-0.4) 0.2
Resistance 25 2.4(0.8) 2.2(0.6) 0.2(-0.2-1.8) 0.1(-1.2-1.3) 0.9
Control 28 3.0(0.7) 2.9(0.6) 0.1(-0.2-1.6)
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116
Figure 4.3.1 (a) Mean changes in HDL levels
Figure 4.3.1 (b) Mean changes in LDL levels
45
46
47
48
49
50
51
52
Pre Post
Mea
n c
han
ge in
HD
L (m
g/d
l)
Aerobic
Resistance
Control
80
85
90
95
100
105
110
Pre Post
Mea
n c
han
ge in
LD
L (m
g/d
l)
Aerobic
Resistance
Control
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117
Figure 4.3.1 (c) Mean changes in TG levels
Figure 4.3.1 (d) Mean changes in TC levels
100
110
120
130
140
150
160
Pre Post
Mea
n c
han
ge in
TG
(m
g/d
l)
Aerobic
Resistance
Control
154.5
159.5
164.5
169.5
174.5
179.5
184.5
189.5
Pre Post
Mea
n c
han
ge in
TC
(m
g/d
l)
Aerobic
Resistance
Control
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118
Figure 4.3.2 (a) Mean changes in ALT levels
Figure 4.3.2 (b) Mean changes in AST levels
45
47
49
51
53
55
57
59
61
Pre Post
Mea
n c
han
ge in
ALT
(m
g/d
l)
Aerobic
Resistance
Control
26
28
30
32
34
36
38
Pre Post
Mea
n c
han
ge in
AST
(m
g/d
l)
Aerobic
Resistance
Control
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119
Figure 4.3.3 Mean changes in hs-CRP levels
2
2.2
2.4
2.6
2.8
3
3.2
Pre Post
Mea
n c
han
ge in
hs-
CR
P (
mg/
L)
Aerobic
Resistance
Control
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120
4.4 Results: Physical Fitness
The SL-DARTS population comprised of sedentary individuals, as per self-reported physical
activity. During the intervention, the measured background physical activities via pedometer
scores were 7500-8000 steps per day. Most of them started structured physical activity for the
first time in their lives after enrolling to the SL-DARTS.
Table 4.4.1 and Figures 4.4.1 and 4.4.2 (a) to (c) summarizes results for baseline (pre
intervention) and post intervention change in resting heart rate, blood pressure (systolic and
diastolic), end of 3 minute step test heart rate, distance covered in 6MWT and the muscular
strength across the groups derived from a linear mixed model analysis for repeated measures
that included the covariates age and sex.
Table 4.4.2 shows the number of participants who completed 6MWT in each stage with mean
heart rate changes.
Screening exercise ECG
Five participants were identified as having abnormal elevation of blood pressure to
progressive exercise during staged exercise ECG testing/screening. They were directed to the
supervising consultant cardiologist. The reasons for abnormal elevation of blood pressure
were identified as sedentary behavior and exercise intolerance. The participants did not have
a history of other comorbidities which would act as contraindications to exercise, as they
were excluded during screening. They were instructed to continue the program.
Cardiovascular parameters
Mean baseline resting heart rate in the total sample was 89 bpm (SE 3.1 bpm) and was
similar across groups. There was a similar absolute reduction in mean post intervention
resting heart rates in the exercise groups compared to the control group.
The baseline levels of blood pressure were within normal ranges. The SL-DARTS population
were on long term antihypertensive drugs (N=25 (29.0%), AT; n=11 (39.2%), RT; n=7
(25.1%), CN; n= 7 (23.3%)) which did not change during the intervention period (Table
4.1.1). None of them were on beta blockers which would alter heart rate response. Mean
baseline systolic blood pressure (SBP) was 126 mmHg (SE 2.6 mmHg) and diastolic blood
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121
pressure (DBP) was 78.6 mmHg (SE 1.8). Only baseline diastolic blood pressure was similar
across groups. The RT group reduced SBP and increased DPB compared to control.
Cardiovascular fitness/Endurance
The resistance group showed a marked post intervention absolute increase in distance
covered in the 6MWT compared to the control group where the aerobic group did not. Post
intervention heart rate was 120, 119 and 110 bpm for the AT, RT and CN groups
respectively.
The YMCA 3 minute step test was offered to all participants but only 25 from each group
consented to do the test. Table 4.4.2 shows the number of participants completed each stage.
Only AT showed increases in participants completing each stage. The RT and CN decreased.
Some participant stopped during the test.
Muscular strength
Baseline muscular strength was comparable within groups. Only aerobic group had a lower
value for leg press. The resistance group increased muscle strength significantly in all
measured muscle groups, and the aerobic group increased muscle strength in the leg press.
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122
Table 4.4.1 Changes in cardiovascular parameters and muscular strength
Variable
Mean (SE)% Mean Change (95% Confidence Interval)
No of
participants
Pre
intervention
(Baseline)
Post
intervention
(After 3
months)
Within group
Difference in
change pre and
post intervention
Intergroup
comparison
vs Control
P value
Pairwise
Resting HR
(bpm)
N=86
Aerobic 28 92.1(3.2) 90.0(3.2) 2.0(-2.4-6.6) 6.6(-6.5-19.7) 0.3
Resistance 28 90.0(3.2) 88.0(3.2) 2.0(-5.7-9.7) 6.6(-4.0-17.0) 0.2
Control 30 87.4(4.0) 92.0(4.0) -4.6(-17.3-8.1)
Resting SBP
(mmHg)
N=86
Aerobic 28 129(2.8) 127(3.0) 1.7(-5.3-8.9) 0.8(-3.2-10.0) 0.9
Resistance 28 126(2.7) 123(2.5) 3.5(-9.9-2.4) 2.6(-6.5-15.4) 0.6
Control 30 121(3.7) 120(4.0) 0.9(-10.1-11.9)
Resting DBP
(mmHg)
N=86
Aerobic 28 79(1.6) 79(1.5) 0.0(0.0) -1.2(-4.5-12.2) 0.8
Resistance 28 77(1.4) 80(1.5) -3.1(-4.5-2.0) -4.3(-5.6-8.5) 0.5
Control 30 80(2.2) 79(1.9) 1.2(2.5-3.1)
3 minute Step test
HRa (bpm)
N=34
Aerobic 10 155.5(3.9) 153.1(3.9) 2.3(-4.6-9.4) -1.2(-0.9-6.8) 0.7
Resistance 14 155.1(3.4) 152.5(3.3) 2.6(-1.6-6.9) -1.0(-.1-5.0) 0.7
Control 10 154.3(4.5) 150.6(4.5) 3.6(-0.3-7.6)
6MWT(m) N=86
Aerobic 28 500.4(13.3) 525.0(11.9) -24.6(-42.1-(-7.1)) 1.1(-22.7-20.5) 0.9
Resistance 28 520.5(14.6) 555.0(13.1) -34.5(-62.8-(-6.1) 11(-40.1-18.1) 0.4
Control 30 491.3(13.6) 514.7(12.3) -23.5(-36.9-(-10.1))
Strength
Biceps curl (lbs) N=86
Aerobic 28 19.6(1.5) 20.2(1.4) -0.6 (-2.2-1.0) 0.4(-2.6-1.8) 0.7
Resistance 28 20.4(1.6) 23.5(1.5) -3.0(-5.0-1.0) 2.8(-5.3-0.2) 0.03
Control 30 20.6(1.6) 20.8(1.5) -0.2 (-1.8-1.4)
Shoulder press
(kg)
N=86
Aerobic 28 25.6(2.5) 28.0(2.6) -2.3(-4.9-0.3) 2.1(-5.7-1.4) 0.2
Resistance 28 29.0(2.5) 33.7(2.6) -4.7(-6.9(-2.5)) 4.5(-.8-1.2) 0.007
Control 30 27.2(2.6) 27.4(2.7) -0.2(-2.7-2.4)
Leg press
(kg)
N=86
Aerobic 28 54.2(5.7) 62.5(5.0) -8.2(-12.9-(-3.6)) 9.3(-19.7-0.9) 0.05
Resistance 28 58.7(6.0) 67.2(5.2) -8.4(-13.7-(-3.1)) 9.2(-18.9-0.5) 0.05
Control 30 61.4(5.9) 60.5(5.1) 0.9(-8.1-9.9)
HR: Heart rate, bpm; Beats per minute, SBP: systolic blood pressure, DBP: diastolic blood pressure,
6MWT:6 minute walk test,a Heart rate measured after 3 minutes of step test
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123
Table 4.4.2. Changes in 3 minute step test in after each stage / minute
Group Total Completed 1 minute Completed 2 minutes Completed 3 minutes One minute Post-test
(Recovery)
Number performed(n)
Pre Post Pre Post Pre Post Pre Post
Aerobic 25 22 23 16 17 10 11 10 11
Resistance 25 22 19 16 15 14 12 14 12
Control 25 24 22 21 15 10 8 10 8
Mean Heart Rate
(bpm)/SE
Aerobic 25 135.0(10.6) 127.1(16.4) 147.5(10.9) 148.3(11.3) 156.8(8.1) 153.9(10.4) 125.0(13.4) 129.4(11.9)
Resistance 25 132.6(12.9) 130.4(12.0) 148.9(10.7) 147.8(15.5) 156.4(10.5) 149.8(14.0) 122.8(12.1) 126.8(14.5)
Control 25 128.2(20.5) 131.0(10.5) 148.2(14.1) 145.1(10.6) 157.8(14.3) 156.7(10.9) 124.4(11.9) 126.4(13.2)
Figure 4.4.1 Mean changes in distance covered in 6MWT
480
490
500
510
520
530
540
550
560
Pre Post
Mea
n c
han
ge in
dis
tan
ce c
ove
red
(m
)
Aerobic
Resistance
Control
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Figure 4.4.2 (a) Mean changes in muscular strength (Biceps curl)
Figure 4.4.2 (b) Mean changes in muscular strength (Shoulder press)
19
19.5
20
20.5
21
21.5
22
22.5
23
23.5
24
Pre Post
Mea
n c
han
ge in
str
engt
h:
Bic
eps
cuir
l (lb
s)
Aerobic
Resistance
Control
24
25
26
27
28
29
30
31
32
33
34
Pre Post
Mea
n c
han
ge in
str
engt
h:
Sho
uld
er p
ress
(kg
)
Aerobic
Resistance
Control
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125
Figure 4.4.2 (c) Mean changes in muscular strength (Leg press)
53
55
57
59
61
63
65
67
Pre Post
Mea
n c
han
ge in
str
engt
h:
Leg
pre
ss (
kg)
Aerobic
Resistance
Control
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126
4.5 Results: Liking and Wanting for food
Table 4.5.2/3/4/5 summarizes results for baseline (pre intervention) and post intervention
change in explicit liking, explicit wanting and implicit wanting across the groups derived
from a linear mixed model analysis for repeated measures. The group effects p<0.05, were
statistically significant.
Explicit liking
The exercise groups reduced liking for all food types except AT, whom increased liking for
high fat non sweet food. The RT reduced liking for low fat sweet food significantly and for
AT it was more for low fat non sweet food. The CN group increased liking for all with more
effect for high fat sweet food (refer Table 4.5.2 and Figures 4.5.1 (a) to (d)).
Table 4.5.2 Changes in Explicit Liking for food types
VAS- Visual Analogue Scale (0-100mm)
Variable
Mean (SE)% Mean Change (95% Confidence interval)
No of
participants
Pre
intervention
(Baseline)
Post
intervention
(After 3
months)
Within group
Difference in
change pre and
post intervention
Intergroup
comparison
Vs Control
P value
Pairwise
High fat Sweet
(VAS)
N=86
Aerobic 28 37.0(4.9) 35.5(4.9) 1.5(-7.9-10.8) 10.7(-2.4-23.9) 0.1
Resistance 28 41.9(5.1) 40.9(5.1) 0.9(-7.8-9.8) 10.1(-2.8-23.2) 0.1
Control 30 35.8 (4.6) 45.0(4.6) -9.2(-18.8-0.4)
Low fat Sweet
(VAS)
N=86
Aerobic 28 43.0(3.3) 42.1(3.6) 0.9(-8.0-9.8) 4.9(-6.3-16.2) 0.4
Resistance 28 50.7(3.4) 41.7(3.8) 9.0(2.8-15.2) 13.1(3.4-22.8) 0.01
Control 30 41.3(3.1) 45.5(3.4) -4.1(-11.6-3.3)
High fat Non
sweet (VAS)
N=86
Aerobic 28 41.6(4.2) 43.9(4.8) -2.3(-13.9-9.4) -1.4(-15.5-12.7) 0.8
Resistance 28 58.4(4.3) 54.9(5.0) 3.4(-4.1-10.9) 4.3(-7.3-16.0) 0.4
Control 30 53.7(3.9) 54.6(4.6) -0.9(-9.8-8.0)
Low fat Non
sweet (VAS)
N=86
Aerobic 28 38.1(4.0) 31.1(4.4) 6.9(-4.1-18.0) 8.6(-5.0-22.2) 0.2
Resistance 28 33.8(4.2) 32.5(4.6) 1.3(-7.2-9.8) 2.9(-9.1-15.0) 0.6
Control 30 38.7(3.8) 40.3(4.2) -1.7(-10.5-7.1)
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Changes in Explicit Liking
Figure 4.5.1 (a) Mean changes in Explicit Liking for HFSW food
Figure 4.5.1 (b) Mean changes in Explicit Liking for LFSW food
0
10
20
30
40
50
60
70
80
90
100
Aerobic Resistance Control
VA
S r
atin
g (
mm
)
Pre intervention Post Intervention
0
10
20
30
40
50
60
70
80
90
100
Aerobic Resistance Control
VA
S r
atin
g (
mm
)
Pre intervention Post Intervention
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128
Figure 4.5.1 (c) Mean changes in Explicit Liking for HFNS food
Figure 4.5.1 (d) Mean changes in Explicit Liking for LFNS food
0
10
20
30
40
50
60
70
80
90
100
Aerobic Resistance Control
VA
S r
atin
g (
mm
)
Pre intervention Post Intervention
0
10
20
30
40
50
60
70
80
90
100
Aerobic Resistance Control
VA
S r
atin
g (
mm
)
Pre intervention Post Intervention
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Explicit Wanting
Both exercise groups reduced the explicit wanting for all types of food except high fat non
sweet food where they increased wanting. RT had a significant reduction in explicit wanting
to sweet food compared to controls.CN group increased wanting to all food types where the
rise for high fat sweet food was marked (refer Table 4.5.3 and Figures 4.5.2 (a) to (d)).
Table 4.5.3 Changes in Explicit Wanting for food types
Variable
Mean (SE)% Mean change (95% Confidence interval)
No of
participants
Pre
intervention
(Baseline)
Post
intervention
(After 3
months)
Within group
Difference in
change pre and
post intervention
Intergroup
comparison
Vs Control
P value
Pairwise
High fat Sweet
(VAS)
N=86
Aerobic 28 32.7(5.1) 32.5(4.9) 0.2(-10.6-11.0) 7.3(-6.4-21.1) 0.3
Resistance 28 41.6(5.3) 38.1(5.1) 3.6(-1.4-8.6) 10.7(-0.1-21.5) 0.05
Control 30 36.6(4.8) 43.7(4.6) -7.1(-16.3-2.0)
Low fat Sweet
(VAS)
N=86
Aerobic 28 44.8(3.6) 42.6(3.3) 2.2(-6.8-11.2) 4.8(-6.5-16.2) 0.4
Resistance 28 49.3(3.8) 42.1(3.5) 7.1(1.3-12.9) 9.7(0.1-19.4) 0.05
Control 30 41.8(3.4) 44.5(3.2) -2.6(-10.2-4.9)
High fat Non
sweet (VAS)
N=86
Aerobic 28 41.3(4.5) 45.3(4.6) -4.0(-13.7-5.7) -3.0(-15.7-9.6) 0.6
Resistance 28 52.1(4.6) 55.1(4.8) -3.0(-10.7-4.6) -2.0(-13.6-9.4) 0.7
Control 30 52.7(4.2) 53.6(4.4) -0.9(-9.5-7.7)
Low fat Non
sweet (VAS)
N=86
Aerobic 28 35.2(4.1) 32.1(4.4) 3.0(-8.2-14.3) 5.8(-7.6-19.3) 0.4
Resistance 28 34.5(4.3) 33.2(4.5) 1.3(-6.0-8.6) 4.1(-6.8-15.1) 0.4
Control 30 39.1(3.8) 41.9(4.1) -2.8(-11.1-5.4)
VAS- Visual Analogue Scale (0-100mm)
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Changes in Explicit Wanting
Figure 4.5.2 (a) Mean changes in Explicit Wanting for HFSW food
Figure 4.5.2 (b) Mean changes in Explicit Wanting for LFSW food
0
10
20
30
40
50
60
70
80
90
100
Aerobic Resistance Control
VA
S r
atin
g (
mm
)
Pre intervention Post Intervention
0
10
20
30
40
50
60
70
80
90
100
Aerobic Resistance Control
VA
S r
atin
g (
mm
)
Pre intervention Post Intervention
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Figure 4.5.2 (c) Mean changes in Explicit Wanting for HFNS food
Figure 4.5.2 (d) Mean changes in Explicit Wanting for LFNS food
0
10
20
30
40
50
60
70
80
90
100
Aerobic Resistance Control
VA
S r
atin
g (
mm
)
Pre intervention Post Intervention
0
10
20
30
40
50
60
70
80
90
100
Aerobic Resistance Control
VA
S r
atin
g (
mm
)
Pre intervention Post Intervention
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Implicit Wanting
RT markedly increased implicit wanting to HFNS food and reduced implicit wanting for
sweet food.AT reduced implicit wanting to low fat sweet food markedly. However, they
increased the wanting to high fat sweet food. The CN changes were similar to the AT group
(refer Table 4.5.4).
Table 4.5.4 Changes in Implicit Wanting for food types
Variable
Mean (SE)% Mean (95% Confidence interval)
No of
participants
Pre
intervention
(Baseline)
Post
intervention
(After 3
months)
Within group
Difference in
change pre and
post intervention
Intergroup
comparison
vs Control
P value
Pairwise
Sweet High fat
(D-RT)
N=86
Aerobic 28 0.51(0.07) 0.29(0.07) 0.21(-0.1-0.5) 0.16(-0.2-0.6) 0.4
Resistance 28 -0.01(0.06) 0.10(0.06) -0.12(-0.4-0.1) -0.17(-0.6-0.2) 0.4
Control 30 0.41(0.08) 0.35(0.08) 0.06(-0.2-0.3)
Sweet Low fat
(D-RT)
N=86
Aerobic 28 -0.33(0.08) -0.16(0.09) -0.17(-0.3-0.01) -0.11(-0.3-0.1) 0.3
Resistance 28 -0.29(0.08) -0.25(0.09) -0.04(-0.2-0.1) 0.02(-0.2-0.2) 0.9
Control 30 -0.18(0.07) -0.13(0.08) -0.06(-0.2-0.1)
Non Sweet
High fat(D-RT)
N=86
Aerobic 28 -0.32(0.07) -0.28(0.07) -0.04(-0.2-0.1) -0.03(-0.2-0.2) 0.8
Resistance 28 -0.29(0.08) -0.43(0.07) 0.15(-0.1-0.4) 0.015(-0.1-0.4) 0.2
Control 30 -0.31(0.07) -0.30(0.06) -0.01(-0.1-0.1)
Non Sweet
Low fat (D-RT)
N=86
Aerobic 28 0.14(0.19) 0.16(0.14) 0.01(-0.2-0.2) -0.01(-0.4-0.3) 0.9
Resistance 28 0.59(0.20) 0.58(0.15) 0.01(-0.5-0.5) 0.004(-0.5-0.5) 0.9
Control 30 0.09(0.18) 0.09(0.13) 0.00(-0.2-0.2)
D-RT: Standardized ‘d-score’
Table 4.5.5 Directional changes in hedonic responses to different food types
Group Explicit liking Explicit wanting Implicit wanting
HFSW LFSW HFNS LFNS HFSW LFSW HFNS LFNS HFSW LFSW HFNS LFNS
AT
N
RT
*
*
*
N
CN N
: Decrease, : Increase, N: No/mild change, Red: marked change within group, *: Significant change
compared to control group
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4.6 Results: Quality of Life
After 3 months of supervised progressive exercise intervention, quality of life scores
increased in all the scales for both resistance (RT) and aerobic (AT) groups (Table 4.6.1). Out
of the eight scales, statistically significant improvements were seen in 5 different scales each
(RT/AT: 5/5 scales). Control (CN) group also increased their scales where 3 scales reduced
(role limitations due to emotional health, emotional wellbeing, and energy). All of the effect
sizes were small.
The resistance group improved in physical functioning, role limitations due to physical
health, role limitations due to emotional health, emotional wellbeing and pain, with a medium
effect sizes (ranging from 0.4-0.6). They experienced similar improvements as compared to
the CN (Table 4.6.2). In addition, RT showed improvement in energy/fatigue, emotional
well-being and social functioning. The baseline values were significantly different in these
scales between the groups (RT and CN) which allowed limited comparison.
In the aerobic group, the scales: physical functioning, role limitations due to emotional
health, emotional wellbeing, social functioning and general health significantly improved,
with medium to large effects sizes. The group comparison showed the same except the
general wellbeing and role limitations due to emotional health which was similar to controls.
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Table 4.6.1: Changes in pre and post intervention SF-36 scores
SF-36 Scale
Resistance Aerobic Control
Mean (SE)% Mean
(95%CI)
Mean (SE)% Mean
(95%CI)
Mean (SE)% Mean
(95%CI)
Pre
(Baseline)
Post
(After 3
months)
Within
group
Difference
Effect
size
Pre
(Baseline)
Post
(After 3
months)
Within
group
Difference
Effect
size
Pre
(Baseline)
Post
(After 3
months)
Within
group
Difference
Effect
size
Physical functioning 77.4
(22.1)
84.6
(18.0)
7.2
(-14.5-1.5)
0.4 74.9
(15.4)
82.7
(12.1)
7.8
(-14.1-1.1)
0.5 72.9
(19.7)
74.5
(21.1)
1.6
(-10.1-3.7)
0.2
Role limitations/
physical health
73.2
(35.3)
90.7
(22.1)
17.5
(-35.2-1.7)
0.6 75.0
(31.8)
82.7
(29.8)
7.7
(-20.1-4.6)
0.2 70.5
(38.5)
75.6
(34.5)
5.1
(-21.5-8.2)
0.2
Role limitations/
emotional health
77.4
(36.3)
95.1
(20.1)
17.7
(-32.3-4.6)
0.6 63.0
(43.7)
79.5
(29.9)
16.5
(-35.0-1.6)
0.4 75.0
(35.9)
73.3
(43.2)
-1.7
(-15.7-13.4)
0.0
Energy/fatigue
70.3
(14.8)
74.4
(14.3)
4.1
(-11.5-1.9)
0.3 64.0
(11.1)
67.3
(17.5)
3.3
(-9.1-3.8)
0.2 60.1
(18.2)
57.6
(19.0)
-2.5
(-5.4-9.5)
0.1
Emotional well-being 70.9
(13.5)
77.3
(15.1)
6.4
(-11.8-1.7)
0.5 58.5
(11.8)
69.4
(15.9)
10.9
(-19.3-4.5)
0.9 61.1
(11.8)
60.5
(17.5)
-0.6
(-5.1-3.2)
0.1
Social functioning
83.0
(22.4)
90.3
(16.4)
7.3
(-14.4-2.3)
0.3 78.7
(17.6)
88.0
(12.5)
9.3
(-17.3-2.8)
0.7 75.9
(18.3)
80.0
(17.9)
4.1
(-11.8-1.5)
0.3
Pain
78.8
(18.3)
85.7
(14.8)
6.9
(-14.5-0.9)
0.5 74.4
(16.8)
74.6
(20.0)
0.2
(-8.5-6.9)
0.0 68.8
(24.1)
73.8
(25.0)
5.0
(-14.9-3.4)
0.2
General Health
57.7
(22.3)
61.7
(11.3)
4.0
(-11.5-4.5)
0.2 46.5
(11.8)
58.4
(14.0)
11.9
(-17.4-5.9)
0.9 49.5
(16.9)
52.7
(17.6)
3.2
(-2.6-3.1)
0.2
Effect size; Cohen’s ‘d’, within group. (pre vs. post intervention), Green: medium effect size, Orange: Large effect size
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Table 4.6.2 Between groups analysis vs control in QoL
Groups SF-36 QoL Scales p-valuea
(Baseline)
Pre-post mean
difference (95% CI)
(Between groups)
Effect sizec
(Between
groups)
RT vs. CN
Physical functioning 0.28 6.8 (-2.5 – 16.2) 0.46
Role limitations due to physical health 0.95 12.4 (-5.3 – 30.1) 0.46
Role limitations due to emotional health 0.77 18.6 (-0.9 – 38.1) 0.58
Energy/fatigue 0.05 11.8 (1.1-22.5) 0.94
Emotional well-being 0.01 9.5 (0.1 – 18.8) 0.98
Social functioning 0.03 6.6 (-3.0 – 16.2) 0.56
Pain 0.21 6.4 (-5.4 – 18.2) 0.52
General Health 0.20 0.6 (-7.7 – 8.9) 0.27
AT vs. CN
Physical functioning 0.55 5.7 (-3.8 – 15.1) 0.41
Role limitations due to physical health 0.87 3.7 (-14.2 – 21.6) 0.15
Role limitations due to emotional health 0.39 7.4 (-12.4 – 27.3) 0.01
Energy/fatigue 0.40 6.6 (-4.0 – 17.1) 0.49
Emotional well-being 0.38 10.2 (1.2 – 19.1) 0.47
Social functioning 0.56 6.5 (-3.0 – 16.0) 0.47
Pain 0.68 -2.7 (-14.5 – 9.1) -0.03
General Health 0.30 2.0 (-6.3 – 10.2) 0.04
aMann-Whitney U test. bMean changes in quality of life scores (post-pre) are compared between groups by analysis of
covariance. cEffect size, Cohen’s D, between groups.
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4.7 Discussion
Study 1 - The effects of supervised aerobic and resistance exercise training on Sri Lankan
adults with type 2 diabetes mellitus: Randomized Controlled Trial
Glycaemia
The SL-DARTS measured the pre and post intervention effects of supervised progressive RT and
AT exercise programs in adults with T2DM. The effects are compared with a control group (CN)
who follow regular standard treatment but did not exercise. The group bias were minimized by
randomized allocation and balancing for covariates. HbA1c was the primary outcome measure
which determined the pre and post intervention change in chronic glycaemia. Further, secondary
outcome measures were conducted to describe pathophysiology and etiology of hyperglycemia.
Fasting blood sugar levels determined the glycemic control during the fasting basal sate. The
fasting insulin and HOMA-IR gave idea about the insulin resistance at the basal level.
All 3 groups reduced the HbA1c levels after 3 months. The effect of AT and RT was higher
compared to control (AT > RT > CN) which was compatible with most studies conducted in
Caucasians. Our study showed reduction in HbA1c levels (in AT; 0.7%, RT; 0.6% and CN;
0.5%) after 3 months. The data from methodologically sound studies with adequate sample sizes
(sample size >30 per group) conducted to date by Church et al. (USA), Segal et al (Canada) and
Kadoglou et al.(Greece) (mean Baseline HbA1c 7.5-8.0%,7.5%,7.5-8.5%) had similar trend (AT
> RT > CN) with slightly lower mean change in HbA1c (0.2-0.6%).
In Asia, with very limited studies conducted; the trend was different. Ng et al. who studied
Singaporeans with an 8 week exercise intervention demonstrated the effect of RT was better
compared to AT and CN (n=30, mean HbA1c 8.0-9.0%, RT vs. AT; 0.4% vs. 0.3%). The study
from India by Shenoy et al. (n=10, mean HbA1c 7.5-8.0%) showed similar effect with much
higher mean change RT vs. AT: 1.8% vs. 1.3%. In SL-DARTS when a subgroup analysis was
conducted in lower HbA1c (<7.5%) and higher HbA1c levels (>7.5%) the outcome changed. In
higher HbA1c levels the effect of RT was high (RT > AT > CN; 1.3%, 1.08%, 0.7%).This was
similar to the Asian counterpart. The lower HbA1c group showed similar trend to the Caucasians
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with AT > RT > CN. It directs to identify when analyzed with similar baseline HbA1c levels the
South Asian Sri Lankans showed the better effect of resistance training to chronic glycaemia.
Most of the previous interventional studies have postulated that when basal HbA1c levels are
high the reduction due to an intervention (drugs or lifestyle modification) is also greater. In the
CN group with higher basal levels the reduction was less compared to the reduction seen in RT
and AT groups. Since the basal levels are not similar the effect was not statistically significant.
Most of the studies used with Caucasians reduction in the same baseline levels were 0.3-0.6%.
Even the effects of different exercise studies are being compared here, it is of importance to note
that there are differences in these studies. Though the baseline Hba1c levels are comparable, the
AT programs were different. The variety of exercises, minutes of total exercise per week,
sessions per week and total duration of the intervention were different across studies. The studies
with Caucasian ethnicity ranged from 45-60 min / sessions, 2-4 times / week, total exercise 130-
240 min / week for 6-9 months. The Asian studies were 30-45 min sessions, 2-3 times / week,
total exercise of 90-150 min / week for 2-4 months. Most of the RT programs across all studies
were similar (7/8 exercises, 3 sets, 8-10 repetitions, starting from 50-60% RM); though the total
duration of the intervention differed. SL-DARTS time duration was short (150 minutes / week
for 3 months). It differed from other studies as an exercise session was 75 minutes and conducted
2 times per week. The frequency per week was minimized to improve compliance and duration
was increased to maintain the adequate dose. The type of exercise training was different with
cycling, walking and stepping done (25 minutes each) in circuit manner. Recently it has been
argued that South Asians need more exercise to reach desired reduction in risk profiles compared
to Caucasians; whereas with regard to glycaemia, SL-DARTS demonstrated currently accepted
duration of exercise have shown to give a reasonable change.
In addition to the differences in the interventions, other baseline characteristics across the studies
are not similar, which limits trying to make comparisons (E.g., age, gender, BMI, duration of
T2DM, use of oral hypoglycemic drugs etc.).
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Changes in FBS, FI, HOMA-IR
In addition to HbA1c, the FBS measured gave a different outcome compared to previous studies.
Post intervention mean FBS levels reduced in CN and AT groups as expected but mean FBS of
RT did not reduce; where they had a marginal increase. This was also observed in the subgroup
analysis. The HbA1c denotes the FBS and the post prandial blood sugar (PPBS) levels. In the RT
group, the reduction in HbA1c in the absence of change in FBS could be due to reduction in the
PPBS. However, PPBS was not measured in the study to confirm this. The change in AT group
was significant compared to the CN.
Fasting Insulin (FI) levels and HOMA IR were used very limitedly in the previous studies and
was not used among South Asians. They both give a direction about the hepatic insulin resistance
which is a primary cause of T2DM. Increase in FI and HOMA-IR in CN implicates developing
insulin resistance, which is possible due to disease progression. The exercise groups increment
was less compared to CN (AT, RT vs. CN; 2.8 p=0.1) which shows possible negative effect of
exercise on disease progression. In contrast, subgroup analysis showed in poorly controlled
T2DM (HbA1c >7.5%) group, AT improved FI levels significantly (p=0.04). Exercise should
primarily improve the muscle insulin resistance compared to hepatic insulin resistance. Muscle
insulin resistance is mainly measured via clamp technique; not via FI/HOMA-IR which measures
the hepatic insulin resistance. Additional energy expenditure with improved lean tissue, leading
to reduction in the glucose load (in HbA1c and the FBS levels) improves the negative feedback
loop in reducing pancreatic insulin secretion and improving hepatic insulin sensitivity. This is
described in the ‘twin cycle’ hypothesis that when there is a calorie restriction (reduced nutrient
intake or increased metabolism by muscle) hepatic insulin sensitivity increase significantly. This
effect has shown that improving muscle insulin sensitivity can indirectly improve the hepatic
insulin sensitivity.
The reduction in fat mass of AT which is discussed in the next chapter must have also
contributed to the improved FI. However, this positive effect of AT was not seen in lower
glycaemia (HbA1c <7.5%) where even there was a decrease in HbA1c levels, FBS and FI levels
did not improve. The reduction in HbA1c can be due to decrease in PPBS via improving of
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muscle sensitivity as an effect of previous aerobic exercise in muscle. Aerobic exercise on
muscle was not enough to reduce the glucose load to improve hepatic sensitivity.
The RT group improved FI levels at lower glycaemia compared to AT whom improved in higher
glycaemia. The RT, induced contraction and insulin dependent improvement in muscle insulin
sensitivity for low glycemic ranges must have been better than AT. In RT where the energy
expenditure is low compared to AT, the mechanism of reducing glucose load leading to hepatic
sensitivity is not compatible. It is possible for ameliorate in mitochondrial dysfunction or
improvement in insulin signaling pathway. The understanding of the nature of common insulin
resistance in muscle a still not conclusive. In higher glycaemia, FI increased in the RT in the
background of a reduction in HbA1c (glucose load).
It can be hypothesized that RT can be more beneficial for reducing chronic hyperglycemia in
poorly controlled compared to tightly controlled T2DM and it reduces insulin resistance in the
tightly controlled. The AT group experienced reduced glycaemia and more benefit in improving
IR in the poorly controlled T2DM.
Anthropometry and Body composition
Most of the SL-DARTS participants were centrally obese according to Asian cut-off values and
the majority were females, consistent with global and regional data. The prevalence of obesity
has doubled globally in the last two decades with a higher proportion of women compared to
men (over 200 million men and nearly 300 million women). Available South Asian data from
large population studies in India suggest the same gender variation.
Body size and %body fat
Obesity in South Asians has characteristic features: high prevalence of abdominal obesity, with
more intra-abdominal and truncal subcutaneous adiposity than white Caucasians. In addition,
there is a greater accumulation of fat at ectopic sites; for example in the liver and skeletal
muscles.
Previous well powered RCTs which studied effects of exercise in Caucasians with T2DM
(Church et al., Segal et al, Kadoglou et al.) showed participants were larger (range of body
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weight; 98-100 kg, BMI; 33-35 kg/m2, WC; 100-112 cm) compared to SL-DARTS participants.
The latter were relatively small, centrally obese, with comparatively thin peripheries,
significantly lighter ~30 kg and WC about 10-20 cm less. In contrast, the %BF of participants
was relatively high compared to their BMI level (BMI 25-27.5 kg/m2: % BF 30-42% compared
to BMI 33-35 kg/m2: % BF 35-37% of Caucasians). However, these different populations shared
similar metabolic disease profiles.
The participants in the present study were similar to Asian counterparts in previously reported
studies. For example, the study by Ng et al. in Singaporeans and Kwon et al. in Koreans,
reported baseline data similar to our participants (weight: 67-69 kg, BMI: 25-28 kg/m2, % BF :
33-35%, WC: 90-91 cm). The only RCT in South Asia by Shenoy et al. did not study the %BF
but Misra et al. in a case control study reported similar values.
The study used two methods (DXA scan and skinfold thickness measures) to determine body
composition, which was more informative to explain the changes due to exercise. The skinfold
method underestimated the % BF compared to DXA. In a previous study, the % BF measured by
2 gold standard methods (BOD POD and DXA) also reported a difference of 2% [204]. With
these data, SL-DARTS contributes new information on adiposity and effects due to exercise in
Sri Lankan and South Asian adults with T2DM.
Body weight and % body fat
One of the main objectives of SL-DARTS was to examine the effect of each exercise mode on %
body fat on Sri Lankans with T2DM.
Body weight and BMI remained unchanged in the exercise groups but increased in controls. The
AT and RT lost fat mass (FM) and gained fat-free mass (FFM), whereas the controls gained
both. As anticipated, the body weight changes were not significant, as the prescribed exercise
dose was not designed to focus on weight reduction.
The literature provides little evidence that exercise-induced energy expenditure alone is a potent
strategy for weight loss, similar to achieved by energy restriction. As weight loss was not the
primary objective of the study, the participants were provided with standard advice on dietary
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management. Participants were instructed not to change their energy intake, which is line with
other study protocols. The habitual dietary intake was not measured as self-report of food intake
is prone to under-reporting, and misreporting. In addition to the extra burden for participants, the
decision was also based on the validity of the data and how much ‘value-add’ the results gave to
the outcomes.
An exercise energy expenditure of approximately 1500 kcal/week, is equivalent to a loss of 2.1%
or 1.8% body fat for men and women, respectively [205, 206]. The total exercise dose in this
study was approximately 650-700 MET/min per week for the AT and 560-600 MET/min per
week for the RT. The non-prescribed physical activity monitored using pedometer step counts
revealed average of 7500-8000 steps per day. Accordingly, activity in addition to intervention
totaled approximately 1000 kcal per week, not enough for significant weight reduction.
With stable body weight, % BF reduced significantly in the AT compared to CN. The effect of
RT was also marked compared to the CN. The reduction in % BF seen in this group of South
Asian adults could be attributed to high baseline % BF and the pre-intervention sedentary
behavior. It should also be noted that the exercise sessions were conducted 2 times/week
compared to 3 times/week, typically used in previous studies. More exercise is commonly
beneficial but sometimes due to feasibility, people may not be able to adhere/perform. So the SL-
DARTS routine can be adopted to people who do not have time to engage in >3-5 times / week,
which would be more practical and rewarding to the patients to reach achievable goals set by the
clinicians.
Regional changes
There were significant regional changes seen in body circumferences and skin fold thickness
measures which are important in describing the body fat depots. These changes were clinically
important and encouraging.
During resistance training, the increase in the size and strength of the exercised muscles are
typically regarded as the major long-term adaptation. Even the increase of muscular protein
becomes evident only after six weeks or more, there is an immediate hypertrophic response, and
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increased tension in the muscle due to training. Wide range of morphological and neurological
factors is known to contribute these changes. The rapid rise in strength at the start of a training
programme within the first 2 weeks is primarily due to neurological adaptations.
The RT and AT groups reduced the MTC; and the subcutaneous thigh fat depots reduced
significantly. Both groups exercised the quadriceps and hamstring muscles using different
exercises (AT did aerobic cycling and stepping, RT did the leg press). The reduction of girth can
be attributed to the reduction in subcutaneous fat layer where the initial increase in muscle
tension and hypertrophy were masked. This can be explained by contrasting changes in a
different site of the body. Compared to the RT, arms were not used in the exercises in the AT.
The MAC reduced more in the AT with significant fat layer reduction. The RT worked the mid
arm muscles significantly with bicep curl, shoulder press and lateral pulldown. In RT, MAC
reduced less and the fat layer reduced more compared to the CN. While reducing the fat layer RT
group preserved the girth compared to loss of FFM of the AT. As spot reduction in fat mass and
subcutaneous skin thickness is not supported in physiology of fat metabolism, the changes in the
reduction of the skin folds can be explained by early muscle tension and neural adaptations due
to resistance training.
The interesting explanation was the reduction of waist circumference (WC) which is clinically
significant as abdominal adiposity (visceral and subcutaneous fat) is directly related to WC and
abdominal skin fold thickness. Post intervention WC reduced in both groups compared to CN.
RT group had more reduction in WC but AT had better reduction in skin folds and trunk fat by
DXA. Even resistance training reduced more WC other parameters were not compatible. RT
group underwent core muscle (back, anterior, posterior abdominal wall and pelvic floor)
facilitation and engagement initially and then the abdominal crunches. Even with less energy
expenditure compared to AT group, the significant reduction in WC is unlikely due to energy
expenditure. The possible explanation is the early changes discussed in muscle during resistance
training, in contrast to reduction in subcutaneous and visceral fat in AT(which is mainly due to
energy expenditure). The changes which occur in resistance training reducing the WC and in turn
the visceral adiposity should be interpreted cautiously.
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The reduction in skin folds described a ‘pattern’ in loss of fat depots following the exercise
program in these sedentary people. Reductions were mostly seen in upper body; mid axilla,
subscapular and triceps and the supra iliac regions. The magnitude of changes was similar to
other studies conducted to date.
AT was more prominent in reduction of skin fold/subcutaneous fat levels compared to RT. The
RT had more effect on maintaining FFM/neural adaptations while reducing the subcutaneous fat.
One limitation of the study was, no attempt to control of dietary intake. Despite the lack of
change in body weight, any changes in dietary intake may have acted as a cofounder for the body
composition measurements.
In conclusion, this group of centrally obese, sedentary, Sri Lankan adults with T2DM who
underwent a short duration moderate intensity aerobic and resistance training program with
moderate to low energy expenditure balanced with time (duration per week), showed significant
changes in anthropometry and body composition. While maintaining body weight, participants
lost more body fat in AT and maintained more FFM in RT. Body composition measured via
skin fold values showed a significant loss (1-2%) of % total body fat in the exercise groups (AT
> RT). Body circumferences and subcutaneous thicknesses were reduced in exercise groups,
where RT reduced WC more. The regional changes in composition were explained via the
morphological and neural changes occurred in muscle and the subcutaneous fat layer. Further
molecular level studies which provide simultaneous data on muscle and fat are needed to explain
the etiology of the changes in detail. In addition, the changes occurred in muscle and body fat
must have influenced the reduction in glycaemia and improved insulin resistance described in 4.1
which was the first primary objective of SL-DARTS.
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Metabolic Parameters
The SL-DARTS measured the pre and post intervention metabolic effects of supervised
progressive RT and AT exercise programs in adults with T2DM as a secondary outcome. The
effects were compared with a control group (CN) following regular standard treatment without
exercise. The metabolic changes of; lipid profile, liver enzymes (AST/ALT) and inflammatory
marker; highly sensitive C reactive protein, are discussed.
Lipid profile
Current evidence of lipid profile and exercise are not conclusive as many studies have been
criticized for methodological flaws or design limitations that make the results somewhat
questionable. These flaws included lack of a separate control group and no dietary control. The
results from different exercise types have been conflicting. SL-DARTS had a control group but
dietary intake was not recorded. Participants received similar advice about diet to a patient with
T2DM.
The most significant previously reported association with exercise and lipid profile was the
increase of HDLs with AT. In this study, the HDL levels deceased in AT and CN groups and
significantly increased in the RT group compared to CN. Previous authors have not reported
definite relative association of RT to AT with regard to HDL. This South Asian adults with
T2DM responded more to RT compared to AT. Previous authors also have suggested that, the
addition of resistance training to aerobic exercise will supplement and possibly enhance the
effects on the lipid profile. Although there is limited literature comparing the modes of exercise,
rendering definitive statements problematic.
Unlike HDL, the effect of exercise on LDL is further inconsistent and there are even completely
contrary results .Some studies showed that AT alone did not change the LDL levels, unless the
weight during this period also changed. In addition, research statistics showed that per kilogram
of body weight loss resulting in LDL reduced by about 0.8 mg/dl. In our group baseline weight
did not change. But LDL reduced more in CN compared to AT which can be due to a higher
baseline value in CN. The RT group significantly increased their LDLs. Currently research are
been conducted in sub-fractions of LDLs. In some patients with mild to moderate dyslipidemia,
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LDLs did not change significantly, but atherogenic small LDL particles decreased, and the
average size of LDL particles increased. Therefore, the impact of exercise on LDL should not be
limited to total LDLs only. The LDL sub-fractions should also be considered. But these effects
are not been investigated with regard to RT which limits the explanation of increased LDL with
RT in our study; and the LDL sub fractions are not measured.
It is suggested that exercise can induce lower plasma TG concentrations which is supported by
limited studies. In contrast, many studies in healthy sedentary individuals and controlled studies
in T2DM, have not shown significant changes in TG levels after exercise. TG levels increased in
all groups but it was less in the intervention groups. This can be due to limited diet control in the
participants. Another explanation could be their high glycaemia (due to T2DM) which can cause
indirect increase in TG due to the diseases process.
Previous results of the similar studies have suggested that exercise time, volume and intensity
have an effect on exercise-induced changes in blood lipids. In order to reduce LDL and TG
levels more, some have suggested to increase the AT intensity. More generally,
recommendations are that traditional low to moderate intensity exercise is beneficial to produce
changes in lipid parameters compared to high intensity exercise. Low intensity exercise done for
longer periods uses fat as the substrate for energy, whereas high intensity exercise uses
carbohydrate rather than fat. Recently high intensity intermittent exercise had been highlighted
for the purpose of weight reduction and lowering atherogenic index [207]. The advantage of high
intensity exercise which has been stated is, the shorter duration of activity which is reported to
having better long term adherence rate.
SL-DARTS exercise volumes and intensities were in par with the current ACSM, ESSA
recommendations. It is apparent that for changes in certain parameters, the general
recommendations may not suffice and may differ for South Asians. Also it is difficult to achieve
higher intensities and volumes in individuals who have limited exercise capacity or other risk
factors.
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Exercise is a lifestyle change that has been recommended for lowering atherogenic index in
adults. The results of this study add to the body of knowledge of the changes of lipid profile to
moderate intensity AT and RT. Previous studies examining the effects of exercise intensity on
lipid and lipoprotein levels have reported conflicting findings. Our data also did not describe a
definite trend. The results were different to only studies conducted in South Asia by Misra et al.
and Shenoy et al. The intensity and duration of exercise to bring about a change in the lipid
parameters are yet to be determined.
Liver enzymes
As most of the participants of SL-DARTS were obese with high adiposity (described in section
4.2), the expectant baseline liver enzymes were high (specifically ALT > AST levels) which
directs towards possible NAFLD in this population.
Confirming the results of the previous studies, the effect of AT and RT in SL-DARTS were not
consistent for AST and ALT levels. Significant finding was the marked reduction in AST levels
by the RT compared to CN. Even AT reduced the level enzymes; the reduction was less than that
in the CN. Since the AST levels are non-specific to liver health and more variable, it is difficult
to attribute it specifically for improvement of liver health. RT group which did not reduce the
ALT shows its less specificity on liver health. Since both intervention groups reduced the fat
mass and glycaemia compared to CN, the expected change would have been reduction of both
AST/ALT compared to CN. In contrast, CN group reduced liver enzymes without reduction in
fat mas or the glycemic levels which should be further explored. It is known that strenuous
resistance exercise and long running can lead to muscle damage which can increase the liver
enzymes if measured within 7 days after exercise. But there is considerable variability in the
extent of response to the heavy muscular exercise. Also varying amounts of physical activity in
daily life, ethnicity and diet, can contribute to this variability. This can be a factor to consider
when interpreting current effects of exercise on liver enzymes in this population.
Inflammatory marker: hs-CRP
Baseline hs-CRP levels of the participants were at the high risk category for CVD owing to the
sedentary nature, obesity and T2DM, which are all risk factors for CVD. The intervention groups
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improved the inflammatory marker by reducing in post intervention which shows the additive
nature of all reduction in risk factors with progressive exercise. This data would be novel as this
would be the first time that these inflammatory markers are investigated in the people with
T2DM in South Asian ethnicity with regard to exercise.
Physical Fitness
In this sedentary centrally obese population of SL-DARTS, fitness parameters were comparable
with the previous similar studies which are limited in South Asian studies. Most of the studies
did not measure the baseline resting hear rate and its variability. Our study population reduced
their resting heart rate in exercise groups which shows improvement of cardiovascular response
to exercise and improved heart rate variability.
Blood pressure was controlled in the groups as they were on long term anti-hypertensive drugs. It
was expected for a population with T2DM, as they would present with multiple comorbidities.
Reduction in systolic blood pressure (SBP) was seen as anticipated in the intervention groups as
Segal et al. and Church et al. reported in Caucasians, and Ng et al. who reported in Singaporeans.
In contrast to these studies, the RT group reduction was marked. The increase seen in diastolic
blood pressure (DBP) in the RT could be due to the increase of peripheral vascular resistance as
an acute effect of resistance training. As the intervention was 3 months, the chronic effects of
reduction in DBP should occur with more prolonged exercise.
The cardiovascular fitness/endurance which was assessed via 3 methods gave different
viewpoints regarding the cardiovascular fitness. The exercise ECG which was a symptom limited
submaximal test (up to 80% HRmax) was performed by all participants and most of them
completed the test in the prescribed protocol. The people who had abnormal blood pressure
responses also did not have any electrophysiological changes in their hearts which would
contraindicate them for progressive exercise. This screening protocol was done for the first time
in Sri Lanka and was not reported in studies in South Asia.
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Even a submaximal exercise test as exercise ECG was completed via walking on a treadmill up
to 6- 9 minutes; the 3 minute step test was physically demanding for the participants. As some of
them refusing to participate and only 45% completing the test showed its difficulty to administer
and complete. Reasons for stopping the 3MST included fatigue, task difficulty, inability to
maintain cadence, balance problems and joint or muscle discomfort.
All the participants in the resistance group who improved in their lower limb strength via
strength training, did not complete the test post intervention. This was similar to the control
group and can be due to the previous experience of high physical demand during the pre-
intervention testing.
The intervention participants who completed the test; showed improvement of their heart rate
after each stage, directing towards an improvement in the cardiovascular fitness. There was a
reduction in the heart rate to achieve a particular work lord, specific to the particular individual
across time. The recovery heart rate which showed heart rate viability and autonomic reactivity
of the heart, did not change significantly with the intervention.
All the participants completed the 6MWT which was less physically demanding. The work load
was depended on each persons’ ability and desire. Most of them achieved only 60-70% of the
HRmax compared to nearly 90% HRmax achieved in the step test. The RT increased their distance
compared to AT and CN which could be due to the increase in muscle strength. Interestingly the
AT who included walking as part of their exercise program, did not increase their distance
markedly compared to controls.
As 6MWT is been investigated more in chronic obstructive pulmonary disease (COPD) patients,
it is recommended that a change of 10% in the distance covered after a rehabilitation program is
clinically important. This population had only about 5-6% improvement with the intervention.
However, it should be kept in mind that the COPD patients started with a lower baseline values
in contrast to our population started with a relatively high baseline value comparable to healthy
populations.
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All muscular strength parameters improved significantly showing the effect of resistance training
on this sedentary unconditioned group of participants with T2DM in Sri Lanka. Since this type of
supervised progressive resistance exercise intervention was done and completed for the first time
in Sri Lanka; added new experiences and skills of prescribing resistance exercise for elderly
population with comorbidities. It was of importance that they completed the program with no
adverse effects, as they were screened and supervised closely.
Apart from the gain in strength in muscle groups, it was evident that their functionality improved
with regard to walking, perceived physical and emotional improvement in activities of daily
living which were detected in the SF-36 quality of life assessment (section 4.6) and also in the
qualitative study (Chapter 5: Study 2).
Liking and Wanting for food
The purpose of this part of the study was to determine the effects of supervised progressive
aerobic training (AT) and resistance training (RT) on preference for different foods types in Sri
Lankan adults with T2DM and compare each program with standard care. The population of SL-
DARTS were urban/sub-urban residents, comparatively at a higher socio economic strata in
education, occupation and income. They were mostly obese sedentary individuals, on regular
treatment for T2DM diagnosed within last 6-7 years.
In the total population of SL-DARTS, the baseline explicit liking and wanting for all food types
were less than 50% (<50mm out of 100mm VAS) except for HFNS food which was slightly
higher. They did not very much prefer any of these foods. This may be due to the disease itself or
the chronic social and environmental influences due to it. The self-control on management of
calorie intake may also had an effect. Another possible explanation is that they were tested at fed
state where the reward of food is blunted. However, the hypothesis on ‘hedonic hunger’ explains
that it is independent of satiety. The reduction in implicit wanting for some food types in CN,
could be related to these factors since they could be regarded as a general T2DM population.
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Irrespective of the low baseline, the preference for food changed over time in all groups
including the control group, who did not follow exercise. The exercise groups reduced explicit
liking and wanting to, majority of the food categories, where non-exercise controls increased to
all foods. The reductions to sweet foods were significant, which is a clinically relevant finding.
The marked reduction of liking and wanting to LFNS food like rice (in AT), is a point to
consider as Sri Lankans major food is rice (and other carbohydrates like string hoppers, bread)
and they consume it more that the western populations. This was a clinically important finding to
inform the patients of possible effects if they adhere to exercise. This effect may not be solely
due to physiological effects of exercise on the hedonic system, but may be due to cognitive
behavioral influence as being in contact with a health care group continually for 3-4 months in a
behavior intervention .Further, the reductions in glycaemia and fat mass (hemostatic functions)
also must have changed and influenced which are discussed in subsections 4.1 and 4.2.
Interestingly, all groups increased their explicit wanting to high fat non sweet. This can be an
immediate effect of the timing of the LFPQ procedure as the participants were tested just after
their breakfast. The typical Sri Lankan breakfast has predominantly rice, string hoppers (LFNS)
with less proteins (like meat egg, fish).Though it was not recorded in the participants, it is a
sound assumption. The conscious wanting for HFNS food can be a due to the reason of this
unavailability of the protein rich food. The groups’ baseline scores of HFNS foods were also
higher compared to other foods (50-60mm in 100mmVAS) which showed they liked and wanted
these food even before the intervention. Interestingly, the RT group increased their scales for
implicit wanting for the same HFNS foods simultaneously. This shows that there is an
underlying wanting developed with resistance training .This underlying wanting developing to
high fat high protein food could be an molecular effect of resistance training where the body
requirement of these macronutrients are increased to build muscle proteins; which need further
studies to confirm.
The marked reduction in implicit and explicit liking and wanting to sweet food of the RT can be
regarded as a significant finding with regard to achieving glycemic control in this population. In
contrast, AT increased their implicit wanting for HFSW and markedly reduced to LFSW. This is
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an area which needs further exploration with regard to their background impressions towards
these specific food items.
In conclusion, it is visible that this population in general did not like and want many of these
foods. The intervention groups generally reduced their hedonic response to food, whereas the
control group increased, which is an important clinical implication. All intervention groups
specifically reduced their liking to sweet food which is important in glycemic control. The effect
of RT was marked, which can be a point to consider when selecting exercise for T2DM. The
increased explicit liking and wanting of AT and the increased explicit and implicit wanting of
RT to high fat non sweet (HFNS) food could suggest that, with exercise there is an increased
preference for high protein foods. Even LFPQ did not vary the foods systematically by protein
content, it is true that the HFNS foods had more protein than the HFSW foods.
Quality of Life
The baseline Qulality of life (QoL) measures were high (60-80) which showed a high percieved
well being amongst the participnats who were comparatively at a higher socio economic strata in
education, occupation and income.These values were higher compared to some of the published
studies among Caucasian ethnicities with T2DM (Italian Diabetes and Exercise Study-IDES) and
similar to some of the large studies on healthy women in USA, highlighting that culture and
ethnicity should be considered when discussing perceived QoL outcomes.
Even the baseline individual scales were comparable/better to western populations, the way the
group had thought about their general well-being was poor across groups (general health scale:
45-60). This is an important point to consider when interacting with patients to improve their
self-esteem. When their preoccupied thought about self is been blunted, they might not see the
positive aspect of life. In such case, educating them with a detail inquiry, will support them to
reflect on their actual wellbeing. With the intervention, the AT improved their perception of
general health considerably.
The baseline social functioning was the highest scale in all 3 groups which represents the Sri
Lankan population with a lot of family and extended family connections. These interactions and
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commitments are discussed in Chapter 5, in the qualitative evaluation of the exercise
intervention. With the high baseline score, improvements in social functioning had significantly
improved in AT with high effect size. AT individuals may seem to benefit from exercise and the
social interactions associated with their activities. As benefits of exercise are commonly
discussed from a biomedical point of view (glycemic control, weight reduction); being “social
animals” we seem to have masked the non-biomedical benefits which are very important to our
quality of life.
Baseline values did not significantly differ among groups except energy/fatigue, emotional well-
being and social functioning which were higher in RT compared to CN (Table 4.6.2).
The improvement in RT which was high in physical health and reduction in pain can be
attributed to the strengthening program they completed. Additionally their limitations of
roles/activities of daily living which are attributed too poor physical and emotional health
improved after the intervention. The exercise program was focused on strengthening the total
body with more functional exercises could have improved their activities of daily living. Such
functional improvements could have increased the sense of emotional well-being.
The AT also improved physical functioning during the intervention but the improvement of pain,
role limitation due to physical and emotional factors were not as significant as RT. Most of the
exercises were routine rhythmic activities such as walking, cycling and stepping stairs compared
to strengthening exercises which incorporated improving range of motion of all major joints and
muscles of the body. The RT program with the use of machines and gym environment was a new
experience for participants compared to the routine aerobic exercises.
In conclusion, the intervention groups improved on most scales of QoL of SF-36 compared to
control. RT group had significant improvements in physical and emotional components leading
to improvements in functionality. The aerobic group improved the general and social wellbeing
considerably. The study showed the total beneficial effect of supervised progressive exercise
compared to a group who received standard care without exercise with regard to well-being. This
would be an important consideration to clinicians and policy makers for future management of
T2DM in Sri Lanka.
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Chapter 5:
Study 2: Qualitative study- Barriers and facilitators to engage in the exercise
program/intervention
5.1. Introduction
Exercise training is integral in the prevention and management of T2DM and other chronic
lifestyle-related diseases [183, 184]. However, despite a strong evidence base, adoption of
appropriate lifestyle practices and, in particular, failure to adhere to physical activity and
exercise in the long-term is a challenging problem for health professionals and staff working in
the health and fitness industry [22, 185]. There is a common tendency for non-adherence to
exercise programs and many individuals returning to their former lower levels of physical
activity after discharge from a rehabilitation program [184]. The strategies to maximise
adherence, starting from the commencement of an exercise program, are fundamental to the
longer-term success of exercise interventions [184].
Among the multitude of exercise interventions carried out to-date on T2DM, the qualitative
information evaluating their success remains limited. Recently in 2013, Tulloch et al. published
qualitative data [187] on T2DM patients’ perspectives of adherence to exercise in a RCT [90].
They concluded peer support, supervision and support from family as facilitators. It is important
to identify further qualitative data generally and contextually for long and short term
improvements of compliance to exercise, which is continuously being debated. But it is incorrect
to assume that the factors can be same for different cultures and countries. In that context,
identifying the qualitative data on South Asian Sri Lankan context will add new information to
the evidence base.
To the best of our knowledge there are no studies conducted to date where the effectiveness of a
RCT (study 1) with regard to participant qualitative experience is assessed. This component
allowed a triangulation approach to the incorporation of quantitative and qualitative data at the
stage of results interpretation which will give contribute to a more applicable outcome.
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5.2 Primary outcome
To identify the barriers/facilitators experienced by participants for compliance/adherence to
different modes of exercise programs. This was the primary objective No: 4 of the main
objectives mentioned in Chapter 3: General Methodology.
5.3 Methodology
1. Critical literature review was conducted to understand the reasons for exercise adoption
and adherence. Most widely used evidence based cognitive behavioural approaches were
reviewed. These behavioural theories were selected based upon their scientific evidence
demonstrating efficacy. The themes to be discussed in the in-depth interviews were selected
from these behavioural theories (Table 5.1).
(A conceptual model was developed (FITTSBALL) combining these behavioral theories to
the leading technical approach (FITT) to exercise prescription (Appendix 6). The objective
was to describe the exercise supervision process.
2. Qualitative study was conducted to assess the response of the participants who adhered to
exercise behaviour and completed the program. In-depth interviews (IDIs) were conducted
to identify the barriers/facilitators experienced by participants for compliance/ adherence to
different modes of exercises. Documented data from recruitment and drop out registries
were used during analysis.
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5.3.1 Critical literature review
The themes to be discussed during in-depth interviews were selected from the behavioural
theories reviewed here, and the results are summarised in Table 5.1.
The Technical Domain
To achieve the desired outcomes, exercise should be prescribed and performed according to a
number of recognised principles, including adequate dose. Exercise dose is typically described in
relation to the type of exercise undertaken (for example, aerobic and/or resistance), how often
(frequency per week) and how long (time or duration) at a given intensity (commonly in relation
to multiples of resting energy expenditure or heart rate). This has been described as the ‘FITT’
principle of prescribing exercise [208].
F - Frequency
I - Intensity
T - Time
T – Type
Using aerobic training as an example, the volume of exercise may be quantified by:
1) “Frequency” as the number of days the routine performed per week;
2) “Intensity” determined by the a percentage of maximal aerobic capacity or heart rate;
3) “Time” as the minutes the aerobic activity or activities are performed per session; and
4) “Type” as the specific mode of aerobic exercise (i.e., treadmill, cycle ergometer, walking,
etc.).
Using resistance training as an example, the volume of exercise may be quantified by:
1) “Frequency” the number of days the routine performed per week;
2) “Intensity” determined by the repetitions performed as a function of the percentage of an
individual’s one repetition maximum (% 1RM - percentage of maximum amount of force that
can be generated in one maximal contraction) for the exercises completed;
3) “Time” as the number of repetitions and sets each session; and
4) “Type” as the specific resistance manoeuvres performed and equipment used [209].
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When an adequate dose is prescribed, a major challenge is associated with the client adhering to
the exercise to achieve the desired short- /long-term benefits [22]. Oversight of the exercise
prescribed is critical as the so-called ‘adequate dose’ may be more exhaustive to some clients
and result in non-adherence [210].
A critical and often overlooked component - Cognitive Behavioural Domain (CBD)
Exercise is a health-related human behaviour influenced by cognition [211]. Incorporation of
physical activity and exercise into the day-to-day lifestyle of an individual who is inexperienced
in the area requires significant behaviour change [212]. A range of cognitive and behavioural
theories have been posited to describe approaches to encourage behaviour change and support
adherence to such changes. Many such approaches have been widely studied over recent decades
using interventional trials [184, 213]. Evidence suggests that the strongest interventions
incorporate a number of theories [184], although others have proposed that a new behavioural
theory should be developed [214] to suit the wider context of current exercise behaviour
interventions.
Considering the current state of the field, it is timely that the CBD and technical domains are
addressed concurrently with the ultimate goal of facilitating a more holistic understanding of
exercise adoption and adherence.
To provide a context for the CBD and identify the themes to be discussed in the IDIs, central
elements of five of the most commonly used theoretical models of health behaviour change were
reviewed [214].
The Trans Theoretical Model (TTM)
The TTM is widely used in behaviour change interventions, was originally developed by
Prochaska (1979) and later improved upon [215, 216]. The thesis of TTM is “that intentional
behaviour change is a process occurring in a series of stages, rather than a single event…” An
individual moves through these stages making decisions regarding the pros and cons of the
behaviour (i.e., decisional balance), developing confidence in maintaining it (i.e., self-efficacy),
while explaining how those changes occur (i.e., processes of change)[217]. Understanding the
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current stage of an individual (i.e., pre-contemplation, contemplation, action, maintenance or
relapse) will necessitate modification of the approach taken by the clinician to support the
desired change. If the person is in the pre-contemplation stage it is unlikely they will adopt the
new behaviour [218].If the person is in maintenance of the exercise identifying the stage would
facilitate to support the long adherence to the behaviour. Identifying the stage of change will
enable the clinician to facilitate the adoption or adherence process.
Social Cognitive Behavioural Theory (SCBT)/ Theory of Self-efficacy
Self-efficacy is the main construct of SCBT proposed by Bandura in 1977 [219]. Self-efficacy is
an individual’s confidence in his or her ability to perform a given task. This is a product of
individual perception of ability to achieve a specific level of performance (i.e., efficacy
expectations) and evaluation of the probable consequences of the specific behaviour (i.e.,
outcome expectations) [211]. Enhancing self-efficacy is one of the main driving forces impacting
the maintenance of adherence to exercise [185]. Self-efficacy may be enhanced via four
different sources: 1) Performance mastery (i.e., primary experience of the person regarding the
effectiveness of the exercise behaviour); 2) vicarious experience (i.e., secondary experience from
others influencing exercise); 3) verbal persuasion/motivation by the trainer, family; and 4)
emotional arousal (e.g., psychological states such as happiness, and physiological states like
feeling of pain) [212, 220]. Self-efficacy is also described in TTM [217] as the construct that
develops confidence and the maintenance of change from one stage to another (e.g.,
contemplation to action). It is recognised as the main factor to impact on the maintenance of
change where it will acts as a facilitator.
Self-determination Theory (SDT)
Self-determination theory considers the interaction and optimisation of patients/clients’
experiences in autonomy, competence and relatedness during behaviour change [221, 222]. By
optimising these constructs, the expected exercise behaviour is more likely to be internalized and
better maintained.
Patient autonomy is a key ethical concern [223], involving and enabling patients to make their
own decisions about health care interventions they may or may not receive [224]. In SDT,
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‘autonomous regulation’ is more effective when one personally endorses the value of a
behaviour (identified regulation) and aligns it with other central values and lifestyle patterns
(integrated regulation) [222]. This process is explained in TTM when an individual changes
from one stage to the next (decisional balance) [216]. This intrinsic motivation of the client is
reinforced when the prescriber/practitioner gives priority to client concerns, supports and allows
a meaningful rationale for change, without applying external controls and pressures
(controlled/extrinsic motivation). People who are autonomously self-regulated tend to display
higher satisfaction, confidence, enjoyment, and trust [225].
Along with a sense of autonomy, internalization requires that a person experience the confidence
and competence to change. Perceived competence is a closely related, but more general variable
of individual aptitude and capacity than self-efficacy [220]. SDT predicts that competence alone
is not sufficient to ensure adherence; it must be accompanied by volition or autonomy.
The third factor described in SDT is relatedness or belongingness perceived by the client, a basic
human need [226]. The process of behaviour adoption and adherence is enhanced with the sense
of being respected, understood and cared for by the practitioner. This form of positive prescriber-
client relationship allows trust and accountability to develop which optimises internalization of
the desired behaviour [227].
Theory of Planned Behaviour (TPB)
The theory of planned behaviour explains that an individual’s intention is the most proximal
predictor of his or her behaviour [228, 229]. This is mediated by the effect of three conceptually
independent determinants: attitudes, subjective norm and perceived behavioural control (PBC)
[229].Attitudes are a person’s overall positive or negative evaluation of the target behaviour, and
subjective norm is a social factor that refers to the perceived social pressure to perform or not
perform the behaviour. Perceived behavioural control refers to the overall judgment of the ability
and the resources available to engage in the target behaviour and is assumed to reflect past
experiences as well as anticipated obstacles. The present view of PBC, is most compatible with
Bandura’s (1977, 1982) concept of “perceived self-efficacy” [219] and also the “competence”
explained in SDT [225]. Self-determined motives or internalised motivation described in SDT
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are hypothesized to be distal predictors of attitudes and PBC, which form intentions. Intentions
are used directly to influence future health-related behaviour change.
Health Belief Model (HBM)
The HBM was one of the first theories of health behaviour change and used widely in long-term
exercise adherence interventions in clinical populations [230]. The HBM theorizes that people’s
beliefs about the risk of getting a disease, and their perceptions of the benefits of taking action to
avoid it, will influence readiness to change their present behaviour. The perceived severity and
susceptibility to the disease, perceived benefits of exercise, arising cues to action (e.g. presence
of disease symptoms), and self-efficacy form core constructs of HBM [214, 230]. A
modification of HBM is the “Exercise Behaviour Model”, which suggests that exercise
behaviour is specifically influenced by the subjective belief towards exercise [231] and explained
via four factors: 1) self-concept; 2) attitudes towards exercise; 3) values related to exercise; and
4) perceived control over the behaviour.
Limitations
Even if attitude and self-efficacy/PBC are optimised, and the patient has moved from pre-
contemplation to contemplation to action; limitations can hinder the ongoing process of action
and maintenance (TTM).It is important that the patient and prescriber are aware of limitations, to
be proactive and to manage them positively. Further, if there are facilitators, for these to be
reinforced. Main limitations to exercise adherence detailed in the literature are as follows.
Health status - including a risk assessment and clearance to initiate an exercise program as
well as identify contraindications (e.g., in the case of heart failure, uncontrolled
hypertension) [232].
Culture - cultural background of the person may be a barrier to adherence to the prescribed
behaviour due to subjective and social norms. For example, Islamic females would not like to
exercise in the open and in the vicinity of the opposite gender [233].
Time - perceived lack of time to engage in the activity is a major barrier. Activities to change
the perception and make exercise a priority is the challenge and is referenced in the ‘Life
satisfaction’ construct [232, 234].
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Accessibility - reduced accessibility to the specialist prescriber due to lack of finance,
transport and infrastructure is beyond the control of the prescriber [232] and is explained in
the “Ecological model” regarding how the environment influences behaviour [235]. When
the environment can be optimised along with the individual training prescription referenced
in this paper, more long-lasting changes can be achieved [236].
Complexity and intensity of exercise prescription - exercise prescription should be easily
understood and adapted to individual capacity. Use of lower intensity, more routine, and easy
forms of exercise have shown increased adherence [210].
Life satisfaction – ‘quality of life’
Life satisfaction and enjoyment is the main driving force in the adoption of any behaviour [214].
The exercise should be enjoyable to compete with other life style behaviours like watching TV,
socialising with friends, engaging in social media, etc. [234]. Secondly, exercise should be
relevant to day-to-day activities and the needs of a person. For example, a young person may be
more body image conscious and want to reduce weight, while an elderly person may like to
improve activities of daily living including improvement of balance and reduction of muscular
discomfort and pain. Personal importance and relatedness will allow the individual to explore
avenues to incorporate exercise into their lifestyle [236].
The themes to be discussed with the participants in the IDIs were selected using the above 2
domains and theories (Table 5.1)
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Table 5.1: Themes discussed in the IDIs
Component Questions Probes
Knowledge What do you understand by
being active?
Should people with diabetes
be active?
a) What is being physically active? What is
exercising?
b) Is it beneficial/not beneficial to be active? And
why?
c) Recommendations of physical activity for
healthy living or diabetes?
Exercise adoption What were the reasons to
start this program?
a) Why did you start?
b) Were you thinking of exercising? Not thinking
of exercising? Already exercising? (Stage of
change when starting the program)
Exercise adherence
(Barriers or
facilitators)
What helped you to
participate in the exercise
program continuously?
a) Beliefs: About exercise, about disease state and
about the person/institution who delivers
b) Self-efficacy : Competence in adhering to the
program, perceived ability, arousal
c) Motivation: internal, external
d) Autonomy (ability to make your own decisions
about the program/exercises)
e) Belongingness (relationship with research staff
instructors, peers)
f) The exercise program (how delivered, by
whom, complexity, enjoyment, benefits)
g) Time constrains? (not enough, enough, not
relevant)
h) Accessibility, Travel
i) Support: friends, family, research staff, work
place.
j) Satisfaction and enjoyment
k) Any other limitations (health status, culture, just
don’t like)
What were the barriers
which did not help you to
participate in the exercise
program?
Suggestions/
Recommendations
How do you think we can
improve this program
further?
a) Setting
b) Exercise program
c) Personnel
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5.3.2 In-depth interviews (IDIs)
The qualitative study was conducted to assess the barriers and facilitators to adoption and
adherence of the exercise programs by conducting In-depth interviews (IDIs). Participants who
only participated in the exercise intervention were invited after completing the exercise program
(study 1). This was carried out within one week after the last session (session 24) of the
intervention.
5.3.2.1 Data collection
Thirty one (31) IDIs (IDI1-IDI31) were conducted by the principal investigator assisted by a
trained research assistant. Face to face interviews were conducted maintaining privacy using a
set of pre-determined semi-structured open ended questions based on the concepts derived from
behavioral change models. The themes were regarding; the stage of behavioral change they are
in, knowledge of exercise, individual’s beliefs, perceived ability, limitations/barriers and
facilitators experienced during the prescribed exercise programs. How they individually
managed/not managed them, and feedback regarding improvements (Table 5.1).
Duration of each IDI was 15-30 minutes. The facilitator provided guidance, maintained focus,
stimulated constructive expression, regulated the flow of discussion and ensured time adherence,
while maintaining a neutral stance on contents of discussion. Adequate time was allowed to all
respondents to fully explain their own opinions, perceptions and experiences. During the
interviews written notes were taken and the responses from participants were audio recorded.
Emotional responses were also recorded. Consent was obtained from the participants for this
process. When data saturation occurred, interview was stopped. The point of data saturation
occurred when participants start mentioning the same facts and ideas they mentioned before.
The number of interviews (N=31) conducted were determined by data saturation which was
revealed during concurrent analysis.
The reasons for non-consent to the intervention and drop out from it were extracted from the
recruitment and drop out registries and were used during analysis of data (Table 5.2).
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5.3.2.2 Data analysis
Directed content analysis of qualitative data was conducted with the assistance of NVIVO v10.0
(QSR International, Southport, UK). The topics/themes were selected prior to the analysis and
participants’ responses were grouped under these topics/themes. The facilitator and two
observers were entrusted with the task of providing an analysis of verbal and non-verbal
responses of participants in each IDI within twenty-four hours of conclusion. The facilitator and
two observers analyzed their respective IDI using their notes and the tape-recorded data
collectively immediately after the conclusion of the IDI. Each interview produced one complete
document, and all documents were collectively analyzed by the research team.
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5.4 Results
Socio-demographic characteristics
All participants who completed the program were eligible to participate in the study where the
first 31 participants enrolled out of 56 who completed (55% of total sample).The interviews were
stopped at IDI31 as data saturation occurred with concurrent analysis. Mean age of participants
was 51.7 ±1 years, and 61.3% were females. The majority of the female participants were
housewives and males were professionals. Most participants were completers of AT program
AT/ RT: 17/14.
Participant responses
The information derived from the IDIs were analyzed according to the below five themes
(directed content analysis).
Theme 1: Knowledge
All patients were asked the whether they knew about the benefits of physical activity. All of
them said it was important. But none of them new the physical activity guidelines (type, intensity
or duration per day/ per week etc.). Most of them mentioned walking as the exercise. None of
them mentioned about resistance exercises to be used.
“Yes we should exercise, but I don’t know the details of how many minutes per day!”(55 years
Female, House wife)
“I had not known about such a long duration that I have to do. But I had known that the exercise
should be done. Yes, I had it in my mind, but didn't have time or opportunity to do…” (Male, 45
years, Nurse)
“I knew that walking must be done usually 45 minutes a day...” (Male, 36 years, Businessman)
When they were asked “did you know whether exercise is important for management of
diabetes?” Most of them said they did not know, but got to know the importance and its effect
after enrolling in the study. Most of them were very happy that they enrolled in the study. It
opened them to a new set of knowledge skills that they didn’t know prior.
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“I have known exercises are important to control obesity. But I didn't know it is important to
control sugar...” (Female, 35 years, Clerk)
“Doctor told me to exercise .But I did not know that it is this important (with surprise)! I thought
main thing to control sugar is to take drugs…” (Female, 45 years, Secretory)
Theme 2: Reasons for starting the program- Adoption
Stage of change
When the participants were asked why they consented and enrolled in the research program;
most of them mentioned that they were planning and thinking to start exercise after their
personal physician advised them. But there was no opportunity or place to start exercise. They
were not fond of walking in the streets or going to a park. Sometimes the park was too distant
and sometimes other important things came up. Even they wanted to start exercising, personal
commitments they had to attend came on the way. Some had started exercise but couldn’t
continue. Most of them were in the ‘contemplation’ phase of the stage of change.
“Yes, I had it in my mind, but didn't have time or opportunity No one motivated me for that”
(Male, 45years, nursing officer)
“There is no special service to do exercise. Even I think of going and walking in the park, it
never happens (laughing). But since I enrolled here I have a responsibility to come… So I tend to
adjust my schedule and attend…” (Female, 52 years, technical officer)
People who were in the ‘pre-contemplation’ stage were minimal in the group. The few who were
not planning or thinking in starting exercise, enrolled in the research out of curiosity, and try and
see what was being done. They though that it might be important when they were invited during
the clinic visit. Their physicians’ advice and the reason that it was conducted by qualified
professionals made them come. Sometimes the participants in the study motivated their families
and friends to attend.
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“I was contacted by you. I wanted to see this new way of managing diabetes, I was not afraid as
a doctor, you know the best… so I wanted to follow. My physician also said that I should
exercise...” (Male 47 years, accountant)
“The doctor at the clinic told me there is a new exercise program being conducted to reduce
blood sugar and control diabetes. As I spoke to you I thought of trying it out.”(Male, 55 years,
driver)
“I was not thinking of doing any exercise .But since Mrs. X is coming here she told me the
program is very good. So I also thought that I should come. But when I started I really liked it...”
(Female, 52 years, house wife)
Belief
The client’s subjective belief of own health status (severity of disease, susceptibility, and signs
and symptoms he/she has due to diabetes) and its relevance of exercise as a treatment have
motivated them to adopt exercise as a behaviour.
“My sugar was not getting controlled. I had to wake up in the night to go to the toilet and I was
losing weight, I wanted to control my sugar. My doctor told me that exercise would help. So I
came to the program...” (Male, 42 years, lecturer)
“I was recently diagnosed with diabetes. My wife was also worried. I wanted to some way get a
cure.”(Male, 35 years, bank clerk)
The qualifications of the exercise prescriber or the recognition of the institute where the
exercise program was conducted; as perceived by the participant, influenced the adoption and
maintenance of the program or the exercise behavior.
“...here, the people are knowledgeable about exercise and this program looked very methodical
when you explained it at our first meeting, so I had confidence...” (Female 55years, retired
teacher)
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“You know the best doctor. I just wanted to follow the routine you gave…” (Male, 50 years,
politician)
“...well it was a one of the main reasons. Because with you present, we have the confidence to
carry out the exercises, because you ensure we carry out the exercises properly”. (Female, 48
years, secretory)
They felt that they are in a well-planned scientific program and the risk is minimal. They were
afraid to go for a normal gyms available outside because they were not sure about safety and
possible risk of injury. The pre and post measurement and the detail care given to individuals
made them very much attached to the exercise program.
“…near my home we have a gym. But I am afraid to go there. I am a patient …I don’t know that
instructors have a good knowledge or not…” (Male, 48 years, draftsman)
Some people believed that exercise is good for them. But they could not initiate it before. The
program was an opportunity for them to engage in exercise.
“..with exercise I can keep my body fit and smart. Normally ladies like to take care of their
body... I had to reduce my tummy (laughing)”. (Female, 48 years, company executive)
Some explained that less complexity and intensity of exercise they did, make them easy to follow
the program. As intensity was geared according to their pace they did not feel much exhaustion
and pain. Even there is a popular belief that you have to feel “pain to gain”, this population liked
the slow progression, being methodical and not becoming exhausted quickly.
“Earlier. I couldn’t lift my legs or shoulder. After sometime I found it very simple. Slowly,
methodically when you do anything that's very easy…” (Female, 52 years, house wife)
“Once I worked with a trainer to do the exercise. I felt it very hard. So I stopped…here she
guided me in the process gradually, so I could continue” (Female, 45years, house wife)
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Reasons for continuous adherence to the program
Improved Ability- Self -efficacy, Perceived Control
Patients were asked why they continued the program for minimum 3 months without dropping
withdrawing (At the initial entry to the program they were informed that they can leave at any
moment if they feel so). Most of them reported that they felt better after few sessions. They were
feeling energetic and the body felt light and relaxed (physical and emotional arousal). They
could move easily, so they wanted to continue.
“At the beginning I felt tired. After that I didn’t feel tired. Body felt very light. Sugar levels
decreased. I could avoid the lethargic type of behavior. Always I had a pain in the body now it is
not there…” (Female, 35 years, computer programmer)
“…really I can't say what the difference was. I felt little bit of difference after doing this, both
physically and mentally. Yes, after doing this stress was reduced. I had a good sleep so I thought
of continuing…” (Male, 45years, nursing officer)
Participants improved perceived ability to perform the prescribed exercise via improvement in
self-efficacy/ competence/ perceived behavioural control (PBC). The sense of performance
mastery (experience of the person regarding the effectiveness of the exercise behavior); was a
facilitator to adherence. Participants mentioned indirect benefits they got while coming to do
exercises which were facilitators to adherence.
“I understood that exercise is very important within the first few days of attending. It grew
interest and I thought of doing in my full capacity…I noticed the change in my body and my
ability after few days.” (Male, 45 years, lecturer)
“I’m very happy to come here, because during the exercise I felt that I can do things I couldn’t
do before.” (Female 48 years, technician)
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Secondary experience and motivation from others further improved self-efficacy.
“…. family members responded in a pleasant way and I was encouraged. A change in my
appearance and I felt like reduction of 20 years in the span of life. This is a reason for
continuing the program.”(Male, 42 years, business man)
Motivation, Support
Peer support
Influence by peers was important when adoption and continuation of behavior. During
contemplation it helped to change into action and maintenance. During action stage the positive
influence from the peers and the sense of doing the right thing made them adhere to the program.
“…that lady who had joined before me told that because of exercise her sugar levels came down.
Because of that I thought of continuing the exercise…” (Female, 48 years, house wife)
Support from the research team
The support they got from the research team and the exercise instructors influenced continuing
exercises adherence. Most of them mentioned the friendliness and welcoming nature of the
research team. It has made them to come for an unfamiliar environment like a gym (Most of
them had not visited a gym before). The motivation provided by the principal investigator and
the team was very encouraging for most of them.
“…environment was very good and the staff were very helpful. It was pleasant to come here…
but I had a small problem (smiling) …the wash room should be cleaner, and those who come to
exercise in the gym should also be responsible for that.” (Male, 50 years, businessman)
“…methodically she taught me how to do exercise, "do like this", “do like that” so because of
that I didn't feel any pain. After exercise I had some muscle pain. But I realize that it is good and
nothing to worry about as she assured me”. (Female, 55 years, ECG technician)
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Belongingness, relatedness and life satisfaction
Some participants valued the social relationships and network they build during the intervention
within the group and with the research team. The mutual collaboration was an incentive for them
to come. The social interaction of being in a group and sense of belongingness made them feel to
adhere with the program. They also felt sense of responsibility and commitment to continue and
finish the research.
“..She (research assistant) was in the age of my daughter. And most of the group were in my age.
I feel like coming to this place just to be with them…but I like exercises too (laughing)”
(58 years, female, retired clerk)
“We are retied, we don’t have much to do at home. So we came here… it was good to keep doing
something rather than staying at home. And also its your research we have to support...”(60 and
55 years, husband/ bank manager and wife/house wife)
Support from family
Most of the participants had family commitments. Some were dependent on transport by their
spouses. Some had to take care of their children and their education. Some had their
grandchildren to take care of .It was very crucial that the family supported them.
“I like to come here, husband also support me to come and he accompanies me. His support was
very important, if I did not get my husband’s support I could not continue.”(Female, 58 years,
house wife)
“I look after my granddaughter. But my daughter wanted me to go to exercise. She took off from
work to look after the little one” (Female, 62 years, retired teacher)
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Barriers for continuing the program
Work commitments
The common reason of “lack of time” was not mentioned by most people. This reason is
normally given by the people who have not initiated exercise. Most responded that they want to
attend sessions but other commitments came on their way, especially the work commitments of
the employed. This was due to the timing of the intervention, which was mainly during the office
hours. Some made extra effort to reschedule their work commitments or arrangements to get
leave from work. They got letters from the research team and the doctor concerned to get leave
from their workplaces.
“It was difficult for me to get leave, as the exercise sessions are from 0830am to 6.30 pm.
Sometimes it was difficult for me to leave the office and come at 4 pm. If I do not come at 4 pm, I
will be late to finish and won’t be able to catch the transport to go home before late. But the
letter provided by the doctor helped me to get some time off for the 3 months when I will be in
this program”. (Female, 55 years, company secretory)
“If we had the sessions in the mornings or evenings outside of office hours, it would have been
easy for me... But for un-employed it was ok...” (Male, 36 years, civil engineer)
“It was difficult to get time off work, other than that, no problems”. (Male, 42 years, clerk).
Family commitments
Main reason for missing sessions by the people who were housewives or retried were that they
had to look after their children or grandchildren. Some had to look into education of their
children and attend to tuition classes with them. They gave priority to that compared to coming
for exercise.
Most grandparents were looking after their grandchildren when their parents were away on
work. This extended family structure exists in Sri Lanka where families are supported by the
extended family. Sometimes when the extra support needed from the family was not available, it
acted as a barrier to the participants.
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“My sons’ afterschool classes fall on Tuesdays and Thursdays where we have the exercise
sessions. I have to be there. Sometime I missed sessions because of that. But later I arranged my
timing accordingly”. (Female, 38 years, house wife)
“I have to look after my grandson. I pick him up from the preschool as my daughter can’t come.
I like it, it’s a priority…but I thought my daughter also should make some arrangements as I
have to look in to my health too.”(Female, 63 years, retired executive)
Accessibility
The commute and distance to come to the gymnasium was a problem. But all attended despite it.
Most mentioned that if they had the gymnasium closer to where they live or work it would have
been easy, and suggested to have these type of services everywhere where people have access to.
At the same time they felt that it would affect the research if they do not attend which they felt
responsible.
“I have to travel about one hour to come here. It’s a problem... but I somehow managed. It
would affect your research if I miss sessions. But after the program I need to go to a closer
gym.”(Male, 48 years, contractor)
“We should have this type of services everywhere…” (Male, 52 years, technical officer)
Lack of enjoyment and autonomy
After informed consent, the SLDARTS participants were randomly selected to either aerobic or
resistance exercise programs where they did not have the chance to change unless they dropped
out. They were trained in each of the exercise programs after this was explained. Some
mentioned that they were bored with some exercise routines (E.g. Stepping of the aerobic
program).Since they were in the program they did not want to change. Some people in the
resistance exercise program wanted to try out different exercises which they thought that would
be helpful. It showed that participant personal desires can act as facilitators or barriers. At the
same time some did not want to change anything in the routines, as they believed what the
research group has prescribed is the best for them.
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“I did not want to do the stepping routine for 25 minutes. It’s boring…but as you said we can
change after 3 months I continued...” (Female, 55 years, company secretory)
“I wanted to do the exercise to my chest rather than the exercise to the shoulder which was bit
difficult. It would have been very enjoyable if you have added that in the strengthening program”
(Male, 37 years, lecturer)
“No, I am happy with it. I know you have planned the best program for us. I want to continue
this after the research too. But I don’t know where.” (Female, 58 years, house wife)
Table 5.2: Data from Recruitment and Drop-out registries
Order of
priority
Reason for non-consent at
recruitment
Reason for drop-out during exercise
intervention
1 Not sure whether will able to continue
the program without drop out
Work commitments (Increased work
load, needed to meet the deadlines)
2 Work commitments Family commitments
3 The timing of exercise sessions within
office hours
Medical problems (Having viral fever,
hospital admissions)
4 Can exercise at home Funeral of a close relative
5 Not interested Had to travel abroad
6 - Meeting up with an accident
7 - Continues workload
8 - Travel distance
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5.5 Discussion
The participants of this qualitative study were the ones who completed the exercise intervention
of SL-DARTS which spanned for about 3-4 months. Since they were previously sedentary, it
was an adoption and adherence to a new behavior. As they consented to take part, most of them
were committed to the research which was conducted. The following discussion which analyze
the barriers and facilitators to exercise adoption and adherence of adults with T2DM in Sri Lanka
should be interpreted in such a background.
The provision of information and knowledge about importance of exercise; with regard to
management of diabetes is a primary approach taken towards patients to follow exercise if they
have a chronic disease. The health care system and providers constantly give information
verbally, or via print and visual media. This population who were an educated group; followed
up by a physician for T2DM, for the last 6-7 years did not seem to know much about exercise. It
showed a gap in the delivery and absorption of information or whether these information were
not of concern to the patients. According to the responses it seems that an availability of a
structured service/program allowed them to get engaged.
The personal (doctors and physiotherapists) and the institution (Faculty of Medicine University
of Colombo) who delivered the program was a major concern to most of the participants. The
thrust they have for qualified professionals to do deliver a scientifically backed-up program,
made them adopt it without hesitation. Most of the people who were contemplating to do
exercise (after their family physicians’ advice) immediately initiated the change (Action). The
other group who were pre-contemplators (who were not considering exercise even they were
asked to); made a conscious decision to get involved as it was provided via a recognized
institution and medical professionals. The belief they have towards the ‘prescriber’ made a
significant impact on adoption and later the adherence. The other crucial factor to consider on
adoption was the ‘stage of change’ they were in. It was unlikely for people to adopt exercise if
they were not in contemplation (as most of the participants were in that stage). The limited
participants who were in pre-contemplation stage traveled faster from pre-contemplation to
contemplation and action due to the prescriber/ institution.
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The ‘belief’ regarding the exercise program; the structured scientific nature of it, gradual
progression and continuous supervision helped them to adopt and maintain the behavior. The
limited exhaustion felt during exercise was considered as a positive factor by this group who
were mainly between 50-65 years. This has been reported previously that less exhaustive
exercise has supported long term adherence. Depending on the age and nature of the participants
the belief they had towards exercise was as such. This was observed differently in the younger
participants who wanted to achieve more with the progression of the program.
The main reason the participants mentioned as a facilitator for adherence was the positive
physical and emotional feedback (arousal) they got from attending the sessions. Even they were
reluctant in the first couple of sessions, they felt happy, relaxed and “feeling good” thereafter. In
the mid-way of the program they felt ‘light’ and were moving quickly. The resistance group felt
strong and the aerobic mainly could move faster; both groups said they became more flexible.
They reduced the ‘aches and pains’ they normally had. All these physical and emotional factors
made them continue the program with excitement. There is evidence that emotional and physical
arousal causes increased adherence to the exercise behavior. Whereas, if it was a negative
arousal (like feeling tired, meeting with an injury, pain), it would cause non-adherence; which
participant did not complain in this study.
With exercise, the participants witnessed their blood sugar levels getting reduced and more
controlled. This was praised by their family physicians which made them further motivated. The
friends and family complimented positively about looking ‘alive” and ‘fresh’. These verbal
persuasions mentioned by the participants had improved their self-efficacy.
The performance mastery developed within the person acted as another facilitator for adherence.
The participants could do better in their routine exercises with the progression of the intervention
(gaining of strength, mastery of technique) which motivated them further. The sense of
achievement made them adhere. All above factors which is mentioned in the theory of Self-
efficacy proposed by Bandura in 1977, collectively supported the participants to adhere to the
exercise intervention.
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Support provided to each individual in various ways to maintain the Action phase of stage of
change, was the other important factor which was seen in this intervention. The various
limitations and barriers which came on the way were managed by appropriate support. Previous
research have identified that these supporting mechanisms have made the person keep adhered to
the desired behavior. The support from the spouse, family, friends, prescriber, and workplace
were identified as sources of support. The husbands who provided transport them to the gym, the
sons who motivated them to go and accompanied them, daughters who released them from their
family commitments are some examples. The people who were employed were feeling more
committed to the exercise when their workplace supported them to this activity by giving leave.
They felt gratitude to the workplace for providing opportunity. At the same time when these
sources of support failed that acted as barriers and limitations to adherence.
The mutual collaboration and connections made with the research group was valued by the
participants which motivated them to continue the exercise program. They were grateful for
providing such service to them. The feeling of belongingness, being respected and equal
opportunity provided were appreciated by the participants. The behavioral constructs like
autonomy, belongingness, relatedness acted as the sources of facilitators to exercise. The
research team was continually in contact with participants. If they missed two consecutive
sessions they called and asked the reason. This type of monitoring and relationships helped in the
process.
There were few barriers for adherence to the program.Even when they were in the Maintenance
stage of the behavior, the family events and work commitments were unavoidable. Some
participants missed sessions and they had to make special effort and arrangements to not to miss
further. Sometimes these adjustments were re-arranging their daily schedule, asking for help
from workplace and the family members. It showed when a person is committed to the behavior
(maintenance stage), he/she make a conscious effort to prioritize the adherence to the behavior.
In contrast, if they were in pre-contemplation or contemplation phase, this conscious effort to
continue or adopt would been minimal.
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The accessibility was another barriers described by the participants. Some had to travel a
distance to attend which was not feasible .They suggested an option to have this type of service
in the nearby city in the future or to engage in the program in a nearby gym.
Difficulty in incorporating exercise to own daily routine was another concern participants
expressed. The SLDARTS had the exercise sessions during the office hours due to feasibility.
This was a barrier to people who were employed, but not for the unemployed. It should be a
factor to be considered in long term exercise interventions which will improve adherence.
The concepts of self-satisfaction and autonomy which acted as facilitators became barriers in
different contexts. The participants were happy with the self-efficacy they were achieving but
they did not like some parts of the exercise programs due to personal reasons; like boredom.
Some valued their autonomy with regard to the programs, where they were comfortable if the
exercise routines were changed according to their desire. In contrast, some were comfortable
with the program where they gave full responsibility to the prescriber to decide on the routines.
We have discussed the barriers and facilitators for adherence to exercise, of a group of adults
who have adopted and completed an exercise intervention. The group who did not consent
during the recruitment (as derived from the recruitment register), did not adopt exercise. Their
main concern was the work priorities and they were not thinking about exercise as an option at
that point. They were not committed, and were not sure whether they were able to continue the
behavior. Main reasons for drop-out from the program (Relapse of stage of change) was the work
commitments and the time constrains they had. In addition, other most expressed reasons were
the family commitments and medical reasons.
All the barriers and facilitators were common to participants from both aerobic and resistance
training groups. The only factor which participants mentioned specific to type of exercise was
the personal liking of different exercises and the boredom of doing routines they don’t like. But
it didn’t show any significant impact on the exercise adherence of the current study. Sine this is a
short term intervention the effect would be minimal for participants to adhere to the best type of
exercise they like.
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In conclusion, the constructs derived from the behavioral theories influenced the adoption and
adherence of the exercise behavior in different magnitudes depending on each specific context
and the background of the person. In general, the stage of change of the person , the factors
which improve their self-efficacy, environmental influences on their believes, the support they
get when faced with challengers, and limitations (work, family) they had, acted as barriers and
facilitators to the adoption and adherence to the supervised exercise intervention which spanned
for 3-4 months.
This evidence suggests that customizing the discussed constructs according to the person and
addressing them, will strengthen their behavior adherence. It will focus how the health care
providers can make informed decisions to their respective programs to improve the quality of the
individual exercise prescriptions.
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Chapter 6: General discussion, future directions and conclusions
Sri Lanka Diabetes Aerobic and Resistance Training Study or SL-DARTS was conducted from
May 2016 to July 2017. SL-DARTS contributed to new knowledge with regard to effects of
exercise in the biomedical and qualitative parameters in T2DM adults from Sri Lanka.
Study Outcome
The research questions developed in the literature review were answered by conducting the 2
studies of SL-DARTS; the main study randomized controlled trial (RCT) (Study 1) to compare
the effects of a supervised progressive resistance exercise program and aerobic exercise program
on behavioral, anthropometric, physical fitness, food preference and biochemical parameters in
Sri Lankan adults with T2DM.Then the Qualitative study (study 2) to assess the barriers and
facilitators for compliance/adherence to the program.
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Table 6.0 Hypotheses and actual outcomes
Hypothesis Variable/parameter Hypotheses Results
Primary
Reduction of Glycosylated Hemoglobin
(HbA1c) RT>AT RT<AT
Reduction of % Body fat RT>AT RT<AT
Barriers and facilitators experienced by
participants RT≠AT RT≠AT
Secondary Hedonic food preference for high-fat
sweet foods:
Reduction of Explicit liking
Reduction of Explicit wanting
Reduction of Implicit wanting
RT>AT
RT>AT
RT>AT
RT≠AT
RT>AT
RT>AT
Reduction of Fasting blood sugar
Reduction of Fasting insulin
RT>AT
RT>AT
RT<AT
RT≠AT (NC)
Lipid profile:
Reduction of TC
Reduction of TG
Reduction of LDL
Increase of HDL
RT>AT
RT>AT
AT>RT
AT>RT
RT<AT (NC)
RT>AT (NC)
AT>RT (NC)
RT>AT
Liver profile:
Reduction of AST
Reduction of ALT
RT>AT
RT>AT
RT>AT (NC)
AT>RT (NC)
Reduction of Highly sensitive CRP RT>AT AT>RT
Increase of Muscle strength RT>AT RT>AT
Increase of Cardiovascular Endurance AT>RT RT>AT (NC)
Reduction of Blood pressure AT>RT RT>AT
Increase of Quality of Life RT>AT RT≠AT
Red: Changes different to initial hypothesis, NC: Not conclusive
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Glycaemia (HbA1c, FBS, FI, HOMA-IR)
The primary objective of the RCT was to determine the effect of a supervised RT and AT
compared to control group on glycosylated hemoglobin (HbA1c) and total body fat percentage in
Sri Lankan adults with T2DM.
This group of centrally obese, sedentary, adults underwent a short duration moderate intensity
aerobic and resistance training program with moderate to low energy expenditure balanced with
time (duration per week).The total exercise dose was approximately 650-700 MET/min per week
for the AT and 560-600 MET/min per week for the RT [203].They were urban/sub-urban
residents who were comparatively at a higher socio economic strata in education, occupation and
income. They were mostly around the age of 50-60 years, on regular treatment for T2DM
diagnosed within the last 6-7 years. Being a high risk population; they were screened and
completed the program with minimal adverse effects.
HbA1c was the primary outcome measure which determined the chronic glycemic status of the
participants and the first hypothesis was that supervised RT is more effective in improving
HbA1c levels compared to supervised AT and control, in Sri Lankan adults with T2DM (table
6.1). The effects of AT and RT on HbA1c were greater compared to the control (AT>RT>CN;
0.7%, 0.6%, 0.5%) which was compatible with most studies conducted in Caucasians. The
subgroup analysis in higher HbA1c levels (>7.5%, poorly controlled) showed that the effect of
RT was high (RT > AT > CN; 1.3%, 1.08%, 0.7%), which was similar to the Asian studies
conducted with similar baseline values. Since participants in this study had a higher baseline
HbA1c value for CN, the total group analysis for the changes between groups was masked. The
initial hypothesis was not supported for the whole group, but was confirmed for the poorly
controlled T2DM group even with fewer participants.
Secondary outcome measures were conducted to describe pathophysiology and etiology of
hyperglycemia; fasting blood sugar levels determined the glycemic control, fasting insulin (FI)
and HOMA-IR provided information about the hepatic insulin resistance during the fasting basal
sate. FI tends not be measured in South Asian exercise studies. Progression of developing hepatic
insulin resistance was less in intervention groups compared to controls which was a clinically
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important finding. It was interesting to see a reduction in FI and HOMA-IR, in poorly controlled
T2DM with AT and in contrast, tightly controlled (HbA1c <7.5%) with RT. The mechanisms
which could be proposed are: in AT due to increased energy expenditure and reduction of fat
mass, the high glycemic individuals indirectly increased hepatic insulin sensitivity. Whereas in
the fairly controlled in low glycemic load, RT induced direct muscular contractions could have
effected increasing muscular insulin sensitivity and improved insulin signaling pathways. These
mechanisms should be further explored in future research.
It is hypothesized that RT can be more beneficial for reducing chronic hyperglycemia in poorly
controlled compared to tightly controlled T2DM. Also RT reduces insulin resistance in the
tightly controlled which prevents further development of the T2DM. The AT can be more
beneficial in reducing overall glycaemia and more beneficial in improving IR in the poorly
controlled T2DM.
Despite the volume and duration of exercise programs being similar to guidelines (130-150
minutes per week), they were delivered in longer duration sessions in short frequency (65-75
minutes per session and 2/sessions /week) compared to traditional prescription (45-60 minutes, 3
sessions /week), which required a lower duration commitment which made it more achievable.
This model is relevant to maintain exercise adherence, as during qualitative study interviews this
was expressed as one of the main barriers for adherence to the exercise program. In particular,
work commitments prevented some participants meeting the prescription requirements.
Body weight
Body weight or BMI did not change. It can be assumed that energy intake did not change. It is
unlikely that measuring dietary intake would have added any value to the study. Indeed, the extra
burden could have reduced adherence.
Body composition
The second part of the first primary hypothesis was, supervised RT is more effective in
improving % body fat compared to supervised AT and control, in Sri Lankan adults with T2DM.
Change in % body fat (by DXA scan and skin fold measurements) refuted this hypothesis.
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Despite no significant changes in body weight and BMI, participants lost more body fat in
aerobic training and maintained more FFM in RT. Body composition measured via skin fold
values and DXA showed more loss of % total body fat in AT compared to RT. It is postulated
that RT would exert a greater reduction in fat mass because of the high baseline % body fat and
low lean mass in South Asians. The energy expenditure induced by the exercise intervention was
not sufficient to achieve substantial changes in body weight.
A variety of measures performed to determine anthropometry measurements (e.g., waist, hip,
mid-arm, mid-thigh) provided information regarding the effects of the different types of exercise
interventions. Body circumferences and subcutaneous thicknesses were reduced in the exercise
groups which were regionally different. Both exercise groups reduced mid-arm circumference
(AT > RT) and mid-thigh circumference (RT > AT) and similarly subcutaneous fat layer in arm
(AT > RT) and thigh (RT > AT). These changes were likely to be due to the type of exercise, the
region of the body/muscles the exercise primarily focused on, and the morphological, neural
changes occurred in muscle and the subcutaneous fat. A significantly greater reduction of waist
circumference (WC) was seen in RT compared to AT, which was clinically relevant as it
correlates with reduction in visceral adiposity. The short term changes in body muscle tension
which occurs after RT can cause temporary reduction in WC. Further, molecular level studies
which would provide simultaneous data on muscle and subcutaneous fat are needed to explain
the etiology of these changes in detail. In addition, the changes occurred in muscle and body fat
will have influenced the reduction in glycaemia and improved insulin resistance which was the
primary objective of SL-DARTS.
A number of secondary objectives were met during SL-DARTS which were; to study the post
intervention changes in blood lipid and liver enzymes, inflammatory biomarkers (highly
sensitive CRP- hs CRP), physical fitness (cardiovascular endurance, muscular strength), liking
and wanting for food and quality of life where hypothesis and the results are summarized in
Table 6.1.
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Blood Lipids
Exercise is recommended for lowering blood lipid profile/atherogenic index in adults. The
results of this study add to the body of knowledge of the changes of lipid profile to moderate
intensity AT and RT. The RT increased HDL levels significantly compared to control which was
clinically significant where the normal documented trend of improvement in HDL was observed
in the AT. There was no conclusive evidence to support that the exercise interventions exerted
changes in lipid parameters and liver enzymes. Previous studies examining the effects of exercise
intensity on lipids and lipoproteins have reported conflicting findings where majority of our data
also did not describe a definitive outcome. The results were also different to the changes in lipid
parameters in studies conducted by Misra et al. and Shenoy et al in India. This could be
explained by the relatively low intensity and duration of exercise programs that were insufficient
to induce detectable changes. SL-DARTS exercise volumes and intensities were similar to the
current ACSM, ESSA recommendations and were mainly directed at reductions in the main
outcomes, HbA1C and % BF. It is apparent that for changes in certain parameters the general
recommendations may not suffice and might not be appropriate for South Asians. It is important
to note that it was difficult to achieve higher intensities and volumes in individuals who have
limited exercise capacity or other risk factors; like the population of SL-DARTS.
Liver enzymes
As expected the baseline liver enzymes were high (specifically ALT > AST levels) which directs
towards possible Nonalcoholic fatty liver disease (NAFLD) in this population with high
glycaemia, obesity and adiposity. The effects of AT and RT on liver enzymes were inconsistent.
The only significant finding was the marked reduction in AST levels (which is not specific for
liver) observed in the RT group compared to control. The AT group experienced a reduction in
the lever enzymes. The reduction was lower than in the control group, who experienced a
reduction in liver enzymes, without a reduction in fat mas or the glycemic levels.
Inflammatory marker hs-CRP
Baseline hs-CRP levels of the participants were indicative of high risk for cardiovascular disease
(CVD) owing to the sedentary nature, obesity and T2DM disease status which are all risk factors
for CVD. The important clinically relevant finding was the intervention groups improved hs-
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CRP, showing the additive nature of reduction in these risk factors (glycaemia, fat mass, etc)
with progressive exercise. These data are novel because it is the first time that this inflammatory
marker is investigated in the people with T2DM in the South Asian ethnicity with regard to
exercise.
Cardiovascular endurance
Exercise ECG administered with using the Bruce protocol was completed by all participants as a
submaximal test via walking on a treadmill up to 6- 9 minutes. In contrast, the 3 minute step test
(3MST) was physically demanding for some of the participants, with some of them refusing to
participate and only 45% completing the test. This confirmed that the 3MST is not an appropriate
test to measure cardiovascular endurance in this population.
Liking and Wanting for food
The Leeds Food Preference Questionnaire (LFPQ), which is a computer-based questionnaire
used to measure liking and wanting for food (hedonic food preference), was used for the first
time in Sri Lankans. In general, the participants did not rate the foods highly compared to
previously reported Caucasian healthy populations. This might be due to the social pressures
associated with being diabetic. As they tend to be asked by the clinicians to reduce energy intake
and control surgery diet, which in turn could affect. The intervention groups generally reduced
their hedonic response to food, whereas the control group increased, which is an important
clinical implication. All intervention groups specifically reduced their liking for sweet foods
which is important in glycemic control. The effect of RT was significant compared to CN which
is important when considering which exercise mode to select for T2DM. The increased explicit
liking and wanting of the AT, and the increased explicit and implicit wanting of RT to high fat
non sweet (HFNS) food, could suggest that with exercise there is an increased compensatory
preference for high protein foods.
Quality of Life
SL-DARTS aimed to evaluate the effects of exercise from a comprehensive array of parameters
which would help to describe and manage the T2DM patient from multidisciplinary aspects. The
assessment of the changes in QoL of T2DM was very important to patients, even though it tends
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to be neglected by the clinicians during the management of diabetes. The intervention groups
experienced an improvement in all 8 scales of QoL of SF-36 compared to the control group. The
RT group experienced significant improvements in physical and emotional components leading
to improvements in functionality. The aerobic group improved their general and social wellbeing
considerably. The study showed the total beneficial effect of supervised progressive exercise
compared to a group who received standard care without exercise with regard to well-being. This
would be an important consideration to clinicians and policy makers for future management of
T2DM in Sri Lanka.
Barriers and facilitators for exercise
The qualitative study was the novel addition to the SL-DARTS. It evaluated the efficacy of the
intervention and the barriers and facilitators for exercise adoption and adherence.
The constructs derived from the behavioral theories influenced the adoption and adherence of the
exercise behavior in different magnitudes depending on each specific context and the
background of the person. In general, the stage of change of the person, the factors which
improve their self-efficacy, environmental influences on their beliefs, the support they received
when faced with challenges and limitations (work, family), were important in the adoption and
adherence to the supervised exercise intervention.
This suggests that personalizing the constructs could improve adherence. It could focus on how
health care providers make informed decisions to their respective programs to improve the
quality of the individual exercise prescriptions.
It is important to cautiously note that the conclusions made in this study are specific to the
outcomes from participants involved in SL-DARTS. It would be unjust to make strong
conclusions about the results of this study, because generalizations to Sri Lankans or South
Asian populations require further studies.
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Parallel Developments
In the background of SL-DARTS and my PhD journey, parallel developments occurred. The
PhD was initiated with the joint/split PhD program between University of Colombo (UOC)
under University Grants Commission (UGC) Sri Lanka and QUT Australia in 2014, creating new
collaborations which strengthened with time. My supervisors visited Sri Lanka 2 times during
beginning and end of the study and met the UOC administration with regard to current and future
collaborations. My stay at QUT during the first 6 months of the PhD in 2015 enabled developing
the study, planning protocols and skills upgrade on clinical exercise physiology (which is a new
area of clinical specialty which does not exist in Sri Lanka). This new skill was practiced and
transferred to the local clinicians, physical training instructors and physiotherapists during the
study. This novel approach on patient care and my background in Sports Medicine directed my
Head of institution, Dean Faculty of Medicine University of Colombo inviting me to develop a
new post graduate diploma/masters program in sports and exercise physiology which is initiated
now.
SL-DARTS created a service arm on clinical exercise physiology for people with T2DM/non-
communicable diseases. Planning the sequence of procedures, equipment purchase, infrastructure
approvals, coordination with laboratories and institutions developed the background set up.
Collaboration with medical consultants (Endocrinologists, Cardiologists, Physicians and policy
makers like Director Non-Communicable Diseases Ministry of Health SL, Medical Director of
NHSL and Dean Faculty of Medicine) during recruitment, screening and intervention, enabled to
identify the need and feasibility of incorporating the service to current patient care. Collectively,
the experiences of doing my PhD will be important for transformation of knowledge and skills
acquired through SL-DARTS to the society and future delivery of sustainable service to the
public. These processes developed over time and positive patient responses prompted the
clinicians requesting to establish the service in the future, in the Sri Lankan health sector. The
policy makers at Ministry of Health Sri Lanka were contacted for possibility of incorporating the
service to the national health services. Investors who learned about SL-DARTS contacted me for
starting up new services in the private sector.
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Implications for Sri Lanka
Findings from this thesis will be presented to Ministry of Health Sri Lanka, as a proposal to
incorporate the clinical exercise physiology service within the national health sector. Private
sector involvement in an application of clinical exercise physiology will be initiated where
industry, research and academic institutions will be connected.
Further research will be conducted in this area with the network build during the PhD with my
supervisors and collaborators as an ongoing process.
Future analysis of data
It is intended that the data produced from this study will be used for more in-depth analyses for
the purposes of more exploration and preparing manuscripts. It is acknowledged that exploratory
analyses could reveal more (e.g. Baseline predictors (e.g., BMI) of changes in Hb1Ac). For the
purposes of this PhD thesis, the data analysis has focused on the specific research questions and
hypotheses.
Limitations
SL-DARTS was conducted during my PhD study period which was approximately 3-3.5 years.
Developing the protocols and executing the study in 13-15 months was a challenge due to time
constraints.
Adaptive covariate randomization was used to allocate participants into groups. A limitation of
this technique is that group assignments sometimes became predictable. A small number of
participants were initially randomly assigned from simple randomization, before the covariate
adaptive randomization technique was applied. Stratified sampling was not applied as
participants were recruited from a roll-in method. Stratified sampling needed all participants to
be identified before group assignment which was not possible because of the time constrains.
Habitual diet before or during the interventions was not measured, and there was no attempt to
control dietary intake. The energy intake did not appear to affect the outcomes, as there were no
changes in body weight or BMI over time.
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8.0 Appendix
1. Standard Operating Procedure – 1 Title: Participant Recruitment into the Sri Lanka Diabetes
Aerobic and Resistance Training Study (SL-DARTS)
2. Standard Operating Procedure – 2 Title: Sri Lanka Diabetes Aerobic and Resistance Training
Study (SL-DARTS) – Exercise Intervention
3. Standard Operating Procedure – 3 Title: Sri Lanka Diabetes Aerobic and Resistance Training
Study – Conclusion of Exercise Intervention and Post Intervention Investigations and
Examinations.
4. Standard Operating Procedure – 4 Title: Sri Lanka Diabetes Aerobic and Resistance Training
Study (SL-DARTs) – Qualitative Study
5. Publications Manuscript 1 :Chathuranga Ranasinghe; Andrew Hills; Godwin Constantine;
Graham Finlayson; Prasad Katulanda; Neil King. Study protocol: A randomized controlled
trial of supervised resistance training versus aerobic training in Sri Lankan adults with type 2
diabetes mellitus: SL-DART Study. BMC Public Health 2017: Accepted
6. Publications Manuscript 2: Chathuranga Ranasinghe, Neil A King, Ross Arena, Andrew P
Hills. FITTSBALL – a dynamic tool for supervision of clinical exercise prescription. Journal
Disability and Rehabilitation. Under Review
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Standard Operating Procedure – 1
Title: Participant Recruitment into the Sri Lanka Diabetes Aerobic and Resistance
Training Study (SL-DARTS)
Purpose
The following procedure provides a guideline on how participants are recruited into SL-DARTS.
This SOP will detail the preliminary screening, investigations, examinations and exercise testing
conducted to recruit the participants into the study, prior to commencing their exercise
intervention.
Scope
The following SOP is a guideline of the processes followed from when a participant is recruited
to SL-DARTS to the time they commence their exercise intervention.
Definitions
Aerobic Group SL-DARTS participants who are undertaking cardiorespiratory
fitness exercises as their intervention.
Resistance Group SL-DARTS participants who are undertaking muscle
strengthening exercises as their intervention.
DEXA Dual Energy X-ray Absorptiometry, is a radiological
investigation used to measure Body Composition and Bone
Densitometry.
Exercise/Stress
ECG
Stress Electrocardiogram is a test that is performed to detect
changes that occur in the heart as a response to exercise.
2D Echocardiogram A form of ultrasound scan used to monitor the structure and
function of the heart.
IPAQ International Physical Activity Questionnaire, is used to
determine participants’ level of physical activity.
SF-36 36-Item Short Form Health Survey, is administered to measure
participants’ quality of life.
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Abbreviations
IB – Information Booklet
Pre-I – Pre-intervention
Post-I – Post-intervention
Pt – Participant
IPAQ – International Physical Activity Questionnaire
SF-36 – 36-Item Short Form Health Survey
LFPQ – Leeds Food Preference Questionnaire
UoC – University of Colombo
PI – Principle Investigator (Dr DC Ranasinghe)
1. Participant recruitment and screening
1.1. Pts are invited and interviewed by PI, from the private and public health sector,
endocrine and diabetic clinics, according to the participant eligibility criteria of the
study.
1.2. Eligible Pts are invited to partake in SL-DARTS and are informed about the study and
what is required of them if they choose to partake, by PI. Informed written consent is
obtained. Information sheet is given to the Pt.
1.3. Willing and recruited participants then attend a session, at the University Gymnasium,
UoC.
2. First session
2.1. The first session or appointment is held at the University Gymnasium, UoC.
2.2. PI will obtain the Pts demographic and socioeconomic details and their consent to
partake in the study.
2.3. PI will obtain their medical history, and screen the Pt using the Physical Activity
Readiness Questionnaire (PAR-Q).
2.4. PI will also conduct a physical examination, which will cover the Pts’ general health,
cardiovascular system, respiratory system and musculoskeletal system. The screening is
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focused on identifying the fitness for the exercise intervention and exclude any
contraindications.
2.5. The eligible Pt will be randomly selected into one of the three groups: Aerobic,
Resistance or Control.
2.6. Then the Pt is required to answer the following questionnaires: IPAQ and SF-36.
2.6.1. The IPAQ is conducted as an interviewer administered questionnaire, either by PI
or by a trained research assistant. Record the Pts responses in their IB (pages 8-
11).
2.6.2. The SF-36 is given to the Pt. They can either complete it during the session, or
take home and return at the next session. Once returned, transcribe the
participants’ responses into the SF-36 (English version) found within their IB
(pages 12-13).
2.7. If Pt is selected into one of the exercise groups (refer to SOP-2) demonstrate warm up
exercises and the exercise routines relevant to their designated group and commence P1
(Practice session 1).
3. Examinations and Investigations
3.1. The following investigations and examinations must be performed to the Pt, prior to
commencing the exercise intervention. Ensure the following are completed within 1-2
weeks of the Pt joining the study (during which time the Pt will be completing their
practice sessions).
3.2. Examinations and investigations conducted at UoC:
3.2.1. The following examinations are conducted by PI, at the University Medical Officer
Health Centre, UoC. All of the following are carried out on the same day.
3.2.2. The participant is requested to arrive at the Health Centre by 8:30am, on the day of
testing, for blood collection, followed by anthropometry and body composition
measurements, and finishing with the LFPQ.
3.2.3. Biochemical Parameter – Blood test
3.2.3.1. Venous blood sample (10 ml) collection is performed by PI, and testing is
conducted at Nawaloka Metropolis Laboratories (private tertiary care
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laboratory which maintain at universal standards).The samples are
transported to the lab maintaining a cold chain by the PI/courier.
3.2.3.2. Pt must fast for 10 hours prior to blood collection. (Pt is asked to fast from
10.30pm, the night prior to blood collection).
3.2.3.3. Once results are received from the laboratory, record results in the Pts IB
(page 7), under the Pre-I section (refer to SOP-4).
3.2.3.4. Give a copy of the test results to the participant, for their records. PI will
explain the test results to the Pts.
3.2.4. Anthropometry
3.2.4.1. The following measurements need to be taken: weight, height, waist
circumference, hip circumference, mid-arm and mid-thigh circumference.
3.2.4.2. The measurements are taken by PI, as per standard criteria.
3.2.4.3. Record all measurements in the Pts IB (page 6), under the Pre-I section (refer
to SOP-4).
3.2.5. Body Composition
3.2.5.1. The skin fold thickness of the following sites must be measured: triceps,
chest, mid-axillary, subscapular, abdomen, supra iliac and mid-thigh.
3.2.5.2. The measurements are taken by PI, according to ISAK and ACSM criteria.
3.2.5.3. Record all measurements in the Pts IB (page 6), under the Pre-I section (refer
to SOP-4).
3.2.6. Leeds Food Preference Questionnaire
3.2.6.1. Before completing this questionnaire, request the Pts to have their breakfast.
3.2.6.2. This questionnaire is to be conducted as a computer quiz. Instruct the Pt on
what is required and how to complete the quiz. The Pt can then take the
practice quiz, prior to completing the real questionnaire.
3.2.6.3. The questionnaire takes about 20mins to complete, and once finished, save
the resulting data in a new file (classified by Pt number).
3.3. Investigations conducted at UoC External settings:
3.3.1. The following investigations are done at an external setting.
3.3.2. Stress ECG
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3.3.2.1. Conducted at the National Hospital, Colombo, by resident ECG technicians
and medical professionals.
3.3.2.2. Pt is given instructions for pre-preparation and is accompanied by PI.
3.3.3. Echocardiogram
3.3.3.1. Conducted at the National Hospital, Colombo, by a Consultant Cardiologist.
3.3.3.2. Pt is given instructions for pre-preparation and is accompanied by PI.
3.3.4. Body Composition – DEXA Scan
3.3.4.1. Conducted at Nawaloka Hospital, Colombo, by resident medical
professionals.
3.3.4.2. Pt is given a referral slip by PI and instructions for pre-preparation, and the
Pt is requested to go and get the scan done within 1 week of the blood
collection.
3.3.4.3. Once report is received from the Pt, record results in the Pts IB (page 7),
under the Pre-I section (refer to SOP-4).
3.3.4.4. Give a copy of the scan report to the participant, for their records. PI will
explain the test results to the Pts.
4. Exercise Testing
4.1. The following tests must be conducted within 1-2 weeks of the Pt joining the program,
prior to commencing intervention. The tests are conducted by PI or a pre-trained
research assistant.
4.2. All tests are done in the University Gymnasium, UoC, using the same equipment, setting
and environment to maintain consistency.
4.3. Strength test (1RM) 1
4.3.1. This test involves three exercises to test upper body and lower body strength
(biceps curl, shoulder press and leg press), and the goal is to determine the one
repetition maximum (1RM) that can be achieved by the Pt.
4.3.2. Biceps curl
4.3.2.1. Demonstrate and/or explain to Pt how the technique is performed.
1 American College of Sports Medicine (2010), ACSM’s Guidelines for Exercise Testing and Prescription, 8th
Edition, New York, Wolters Kluwer/Lippincott Williams & Wilkins
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4.3.2.2. Begin with the minimal dumbbell weight of 5lb, then increase incrementally
to the maximum weight the Pt can lift.
4.3.2.3. Record the maximum weight and the date in the Pts IB (page 6), under the
Pre-I section (refer to SOP-4).
4.3.3. Shoulder press & Leg Press
4.3.3.1. Demonstrate and/or explain to Pt how the technique is performed and correct
use of equipment.
4.3.3.2. Adjust the equipment to accommodate the Pt.
4.3.3.3. Begin with the minimal weight of 5kg and 11kg for shoulder press and leg
press, respectively, then increase incrementally to the maximum weight the
Pt can press.
4.3.3.4. Record the maximum weight and the date in the Pts IB (page 6), under the
Pre-I section (refer to SOP-4).
4.4. Step test2
4.4.1. Ensure the participant is fitted with the heart rate monitor prior to starting the test.
4.4.2. Determine the Pts resting heart rate and record in the IB (page 6), under the Pre-I
section.
4.4.3. Position the wooden step box
4.4.4. The participant must step at a fixed rate, which will be prompted by an audio beat
(96bpm) via a metronome.
4.4.5. The test is run for 3 minutes, unless the participant cannot complete the test for
some reason (e.g. exhaustion).Ask for any difficulty like chest pain, shortness of
breath etc. If complain difficulty stop the test and inform PI.
4.4.6. Monitor the Pts heartrate throughout the test and record the heart rate readings at
1min, 2min,3min and 4 min(during sitting after the test) in the Pts IB.
4.5. 6min Walk test (6MWT)3
4.5.1. Ensure the Pt is fitted with the heart rate monitor prior to beginning the test.
2,3 American College of Sports Medicine (2010), ACSM’s Guidelines for Exercise Testing and Prescription, 8 th
Edition, New York, Wolters Kluwer/Lippincott Williams & Wilkins
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4.5.2. Check the Pts resting heart rate and record in the Pts IB (page 7), under the Pre-I
section.
4.5.3. Place two markers 10m apart, to mark the path the Pt must walk.
4.5.4. The Pt must walk the marked circuit, for 6 minutes. Advice the Pt to walk briskly,
and maintain the pace for the duration of the walk, or for as long as possible.
4.5.5. Once the Pt begins, tally the amount of laps completed by the Pt. (no. of laps
multiplied by 20 will equate to the distance walked).
4.5.6. Once the walk is completed, measure the Pts heart rate. Record the heart rate, the
distance walked and the test date in the Pts IB (page 7).
5. Commencing the Intervention
5.1. Once all testing is complete, the participant may begin their intervention.
5.2. Refer to SOP-2 for details on the exercise intervention part of the study.
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Standard Operating Procedure – 2
Title: Sri Lanka Diabetes Aerobic and Resistance Training Study (SL-DARTS) – Exercise
Intervention
Purpose
The following procedure serves as a guideline for the exercise intervention part of SL-DARTS.
This SOP will specify the duration of the intervention and detail the training regimens to be
undertaken by the participants of the study.
Scope
The current SOP is a guideline of the processes to be followed for the duration of a participant’s
intervention, from the first practice session to the completion of the intervention.
Definitions
Aerobic Group SL-DARTS participants who are undertaking cardiorespiratory
fitness exercises as their intervention.
Resistance Group SL-DARTS participants who are undertaking muscle
strengthening exercises of their intervention.
Abbreviations
IB – Information Booklet
Pt – Participant
PI – Principle Investigator (Dr DC Ranasinghe)
1. Duration of the exercise intervention
1.1. The exercise intervention is carried out at the University Gymnasium, University of
Colombo.
1.2. The duration of the intervention is approximately 31
2 months. There are 2-4 practice
sessions, and 24 intervention sessions. Ideally, Pts attend 2 sessions a week, enabling
them to complete the program in about 14 weeks.
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1.3. The duration of the intervention will be prolonged if a Pt fails to attend any sessions, as
they must attend a total of 24 sessions, and any missed session will need to be
compensated for.
Practice Intervention
P1 P2 P3 P4 I1 I2 I3 I4 I5 I6 I7 I8 I9 I10 I11 I12 I13 I14 I15 I16 I17 I18 I19 I20 I21 I22 I23 I24
Wk 1 Wk 2 Wk 3 Wk 4 Wk 5 Wk 6 Wk 7 Wk 8 Wk 9 Wk 10 Wk 11 Wk 12 Wk 13 Wk 14
2. Practice sessions
2.1. Generally, there are 4 practice sessions. This may be shortened or extended depending
on the progress of the Pt.
2.2. The practice sessions are conducted in the same timeframe as when Pts are undergoing
the initial pre-intervention examinations and investigations (detailed in SOP-1).
2.3. These sessions are employed to gradually introduce the Pt into the exercise intervention;
allowing time to train the Pt in the correct techniques involved and for them to
physically adjust to regular exercise.
2.4. When commencing practice sessions with a new Pt, begin with low intensity and
minimal duration of exercises, and then gradually increase to the desired intensity and
duration.
2.5. Each Pt is given a water bottle and towel at the beginning of the intervention. Advice the
Pts to bring water to every session and drink a full bottle of water (or more) throughout
the session.
2.6. Advice the Pt of the ground rules of the gymnasium (e.g. Use of toilets, Use of spare pair
of sports shoes to be used etc.)
3. Exercise intervention - Aerobic group
3.1. Pts selected into the aerobic training group undertake a regime of three aerobic exercises
for the duration of the intervention: Cycling, Stepping and Brisk Walking.
3.2. Exercise administration:
3.2.1. The intervention sessions require the Pts to complete 25 mins of each exercise,
amounting to a total 75 mins of aerobic exercise.
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3.2.2. During the practice sessions, firstly, introduce the Pt to the aerobic regimen with a
minimal duration of 10 mins per exercise. Then, gradually increase the duration of
the exercises to the desired 25 mins. Once the Pt can complete 25 mins of each
exercise, without complaint, they may begin their intervention.
3.2.3. The intensity of the exercises is to be determined based upon the Pts heart rate;
monitor the Pts heart rate during exercise and ensure it is kept at ~60-70% of their
maximum heart rate (Heart Rate max) and/or 12-14 level of Borg Rating of
Perceived Exertion (RPE) scale.
3.3. If the treadmills are available, it is preferable the Pt commences the session with Brisk
Walking, as it serves as a good warm-up. If not, advice the Pt to walk briskly the length
of the gym, for 5 mins, prior to starting (with cycling or stepping).
3.4. Advice the Pts to take a break in between each exercise, and drink water as required.
3.5. Brisk Walking:
3.5.1. Instruct Pts on how to operate the treadmill and allow them time to familiarise with
the equipment. Teach safety measures of using the equipment.
3.5.2. Adjust speed and incline as required. At the beginning of the study, begin with
minimal speed and no incline, e.g. speed-3, and then gradually increase speed as
the Pts heart rate stabilises.
3.5.3. Walking speed on the treadmills are only increased to a maximum of speed-6, as
any speed beyond that would require the Pt to jog/run. Once a Pt reaches this
maximum speed and their heart rate has stabilised, the incline on the treadmill can
be increased for a fraction of the exercise.
3.5.4. Monitor the Pts heart rate. Record max heart rate, duration and speed in their IB.
3.6. Cycling:
3.6.1. Instruct the Pt on how to adjust the equipment. The Cycle should be adjusted so
that when the Pt is seated with their feet placed on the pedals, their extended leg is
positioned at a 15° flexion.
3.6.2. Adjust resistance to the required level. (At the start of the intervention, begin with
low resistance, e.g. resistance-2, and then gradually increase resistance as the Pts
heart rate stabilises.)
3.6.3. Instruct the Pt to maintain a momentum between 50-60 RPM (rotations per min).
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3.6.4. Record the duration, resistance and Pts max heart rate reached during cycling, in
their IB.
3.7. Stepping:
3.7.1. Prepare the ‘step’ necessary for this exercise by stacking the steppers on top of
each other. Generally, 3 stacked steppers, is the height of the step.
3.7.2. The Pt is required to step on and step off, by placing their dominant foot first, and
maintain a steady pace throughout the exercise.
3.7.3. Record the duration and Pts max heart rate reached (if measured), in their IB.
3.8. Warm down: after completing the exercise regimen, ensure the Pt completes a selection
of static stretches.
3.9. Throughout the intervention, during the exercise sessions, enquire regarding Pts general
wellbeing and quality of life. Record the Pts comments regarding these matters, as well
as any general feedback or complaints they may have regarding the exercise regimen.
4. Exercise intervention – Resistance group
4.1. Pts selected into the resistance training group undertake a regime of 7-8 different
resistance training exercises. This will include a combination of multi-joint and single-
joint exercises covering upper body, lower body and core.
4.2. The regimen involves the following exercises: Bicep curl, LP down, Shoulder Press, Leg
Press, Squat, Ab curl, Heel raise and Leg extension/curl. (Exercises may be excluded
depending on a Pts limitations).
4.3. Exercise administration:
4.3.1. The intensity of the techniques will vary with each Pt. However, the amount of
repetitions and sets are kept constant for all participants. All Pts must complete 8
repetitions and 3 sets of each technique, with the exception of Ab curl and Heel
raise, where the Pts are required to complete 10 repetitions and 3 sets.
4.3.2. At the start of the intervention, during the practice sessions, the Pt is not required
to complete all 3 sets. They may start by completing 1-2 sets. Once they are
comfortable completing all 3 sets, and have learned the correct technique with
each exercise, they may commence their intervention sessions.
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4.3.3. When completing 3 sets for each exercise, ensure the Pt rests for at least 1-2
minutes between each set.
4.3.4. Initially, the intensity of the exercises administered should be about 40-50% of the
Pts’ 1RM (1 repetition maximum), or an intensity that they can manage for 8
repetitions. Then, the intensity should be gradually increased, at an approximate
rate of 10% per every two weeks, as the Pts’ endurance and strength increases.
4.4. Prior to commencing the resistance training techniques, ensure the Pt completes warmup
exercises (5-10 mins on the treadmill) and dynamic stretches, to stretch their legs, arms
and torso.
4.5. For each of the resistance techniques, demonstrate and/or explain to Pt how the
technique is performed and the correct use of equipment (if equipment is required).
4.6. Advice Pts to take ample rest between each technique and to drink water throughout the
session.
4.7. For each technique completed by a Pt, record the intensity, repetitions and sets in their
IB.
4.8. Warm down: after completing the exercise regimen, ensure the Pt completes a selection
of static stretches.
4.9. Throughout the intervention, during the exercise sessions, enquire regarding the Pts
general wellbeing and quality of life. Record the Pts comments regarding these matters,
as well as any general feedback or complaints they may have regarding the exercise
regimen.
5. Mid-intervention investigations
5.1. Throughout the duration of the intervention, there are a number of investigations that are
carried out, in excess of the pre-intervention examinations and investigations detailed in
SOP-1.
5.2. At certain intervals during the intervention, a Pts blood pressure (BP), blood glucose
level (BGL) and daily step count will be monitored.
5.3. Blood Pressure
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5.3.1. Commonly, a Pts’ pre and post blood pressure is monitored in their initial couple
of sessions, and then during beginning of each session throughout their
intervention.
5.3.2. However, with Pts who suffer from hypertension or show an increased BP reading
during their first session, their BP (pre and post) will be checked on a regular
basis.
5.3.3. The BP will be monitored by PI.
5.3.4. Record the measured BP reading in the Pts IB, under the appropriate session.
5.4. Blood Glucose Level (BGL)
5.4.1. The participants’ pre and post BGL is monitored in the middle (Session I12) and at
the end (Session I24) of the intervention.
5.4.2. BGL is monitored using a blood glucose monitor, and is done by PI or a trained
research assistant.
5.5. Daily Step Count
5.5.1. This is monitored during the middle of the intervention, continuously for 7 days.
5.5.2. Upon reaching session I12 or I13, the Pt is given a pedometer (Yamax Digi-
Walker-SW-700) and a chart to record the data in.
5.5.3. Explain to the Pt how to operate the pedometer and what needs to be recorded in
the chart. The Pt must record the date, time of waking, time when retiring to bed,
and their total step count for the day in the chart provided.
5.5.4. The Pt must wear the pedometer for 7 days and record their total daily step count.
On these days, the pedometer must be worn by the Pt at all times except at bath
and the time spent at exercise sessions.
5.5.5. Once all 7 days are completed, the chart and pedometer needs to be returned.
6. Completion of the intervention
6.1. When a Pt has attended 24 sessions in total (excluding practice sessions), their exercise
intervention is complete.
6.2. When completed, the Pt needs to undergo, all the investigations, examinations and
exercise testing they completed prior to commencing the intervention. The Pts also need
to complete the IPAQ and SF-36 questionnaires, as well as the LFPQ. (Refer to SOP-3).
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Standard Operating Procedure – 3
Title: Sri Lanka Diabetes Aerobic and Resistance Training Study – Conclusion of Exercise
Intervention and Post Intervention Investigations and Examinations.
Purpose
The following procedure details the standard processes followed upon completion of the
exercise intervention. This will outline the final investigations, examinations and exercise
testing to be completed by participants.
Scope
This SOP is a guideline for the investigator and research assistants of SL-DARTS, detailing
the processes carried out once a participant has completed their exercise intervention.
Definitions
IPAQ International Physical Activity Questionnaire, is used to
determine participants’ level of activity.
SF-36 36-Item Short Form Health Survey, is administered to measure
participants’ quality of life.
Abbreviations
Pt – Participant
IB – Information Booklet
Post-I – Post Intervention
1. Post Intervention Testing
1.1. Once a Pt reaches the end of the exercise intervention, they must complete a series of
tests. All the preliminary testing they completed prior to commencing the intervention
(detailed in SOP-1), must be completed again.
1.2. All testing and procedures remain unchanged, only differing factor is that now they are
undertaken following completion of the intervention. These will follow the same
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procedures as detailed in SOP-1, therefore, the step-by-step procedures will not be
repeated in the present SOP.
1.3. Each of the tests described under section 3, SOP-1, will need to be completed again. The
2D-Echocardiogram is excluded, it is only required at the beginning of the intervention.
1.4. The following examinations, investigations and exercise testing need to be completed:
1.4.1. Examinations and investigations done at UoC:
1.4.1.1. Biochemical Parameters – Blood investigations to be sent to external
laboratory
1.4.1.2. Anthropometry
1.4.1.3. Body Composition- Skin fold thickness measures
1.4.2. External investigations:
1.4.2.1. Stress ECG
1.4.2.2. Body Composition – DEXA Scan
1.4.3. Exercise testing:
1.4.3.1. Strength test
1.4.3.2. Step test
1.4.3.3. 6-Minute Walk test
1.5. Conduct testing as per procedure outlined in SOP-1 (Section 3 & 4). All resulting data
and measurements are to be recorded in the Pts IB, as mentioned in SOP-1, but under the
Post-I section.
2. Questionnaires
2.1. Upon completion of the exercise intervention, Pts are required to complete the SF-36,
IPAQ and LFPQ questionnaires.
2.2. SF-36 – 36-Item Short Form Health Survey
2.2.1. Mark questionnaire as ‘Post-Int’ and fill in Pt number in top right hand corner.
Give to Pt to complete.
2.2.2. Pt may complete the questionnaire during the session, or take it home and return
once completed.
2.3. IPAQ – International Physical Activity Questionnaire
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2.3.1. This questionnaire is conducted as an interview, by Dr DC Ranasinghe or a trained
research assistant. Mark questionnaire as ‘Post-Int’ and fill in Pt number in top
right hand corner.
2.3.2. Record the Pts responses on the questionnaire.
2.4. LFPQ – Leeds Food Preference Questionnaire
2.4.1. This questionnaire is to be conducted as a computer quiz. Instruct the Pt on what is
required and how to complete the quiz. The Pt can then take the practice quiz,
prior to completing the real questionnaire.
2.4.2. The questionnaire takes about 20mins to complete, and once finished, save the
resulting data in a new file (classified by Pt number).
3. Qualitative Study
3.1. A qualitative study must be carried out at the end of the intervention. This is to be
conducted as an in-depth interview with the Pt, who have recently completed the
exercise intervention.
3.2. This procedure is detailed in a separate SOP, please refer to SOP-4.
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Standard Operating Procedure – 4
Title: Sri Lanka Diabetes Aerobic and Resistance Training Study (SL-DARTs) –
Qualitative Study
Purpose
This SOP will detail the procedures followed when conducting the qualitative study component
of SL-DARTs. The interviews to be conducted and necessary qualitative data collection and
processing will be outlined.
Scope
This SOP is a guide for the principal investigator and the research assistants of SL-DARTs on
the procedures to be followed when conducting the Qualitative Study.
Abbreviations
Pts – Patients
IDI – In-depth interview
FGD – Focus group discussion
1. Interview/Group Discussions
1.1. A qualitative study must be carried out at the end of the intervention. This is to be
conducted as an IDI with one Pt, who have recently completed the exercise intervention.
1.2. The interview is conducted by the principle investigator (Dr DC Ranasinghe), and aims
to discuss the Pts knowledge, perception and barriers to partaking in the exercise
program.
1.3. Record the date, time, place and names of the participating Pts.
1.4. The interview needs to be audio recorded. Notify Pts prior to conducting the interview
that their responses will be recorded and ensure their permission is obtained before
proceeding.
1.5. The ‘Guide to Focus Group Discussion-In Depth Interviews’ (Annexure 1) should be
used as a guide to prompt the interview.
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1.6. The IDI will aim to discuss three major components: knowledge of physical activity and
exercise, barriers or facilitators to being active and suggestions/recommendations
regarding the completed intervention.
1.7. Length of the interview is kept between 30-60mins.
2. Transcription and Translation of Interview
2.1. The IDI is analysed using notes (verbal and non-verbal responses of participants) and the
tape-recorded data collectively immediately or within twenty-four hours after the
conclusion.
2.2. The audio recorded interviews must be transcribed verbatim by hand and documented.
One document should be prepared for each IDI
2.3. The transcribed interviews should then be translated to English and typed as a word
document. During translation, it is essential to ensure integrity to the original opinions
and emotions conveyed by the Pt.
2.4. Once the transcribed copy and the translated copy are complete, ensure all components
are documented together. Attach the filled in ‘Guide to Group Discussion-In depth
Interviews’ as the front page of the assembled document.
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Annexure 1
Guide to Focus Group Discussions-In depth Interviews
(for the investigators)
The study on effects of progressive resistance and aerobic exercise training on behavioral, anthropometry, physical fitness, appetite and biochemical
parameters in Sri Lankan adults with type 2 diabetes mellitus.
(Sri Lanka Diabetes Aerobic and Resistance Training (SL-DART) Study)
QUT Ethics Approval Number XXXXXX
Introduction
Thank you for providing us your valuable time by participating in this discussion. Today we will be
discussing about knowledge, perception and barriers to engage in the exercise program we conducted in
the past 3 months. Understanding these information and barriers will be useful to implement
appropriate interventions for you and other participants with T2DM.
We want to hear your opinions, and remember that there are no right or wrong answers. You are free to
answer to the questions in any way you feel comfortable. You can refuse answering if you do not want
to answer at all. If there is any unclear question do not hesitate to clarify and make us to explain more
on it. We are planning to keep a tape record of this conversation to enable us to clarify unclear areas of
this discussion later; we hope that you will consent to this. We guarantee that what is said will be kept
strictly confidential.
Be comfortable – we hope you will find the session interesting and enjoyable.
Respondent register
Date:
Time:
Place:
Name of the note taker:
Names of the observers:
No Name Age Gender Education level Profession
1
2
3
4
5
6
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Theme – Perception and knowledge physical activity and exercise
Component – Knowledge
Question 1: What do you understand by a being active?
Probes
a. What is being physically active? What is exercising?
b. What do you know about recommendations of physical activity for healthy living?
c. Do you think is beneficial to be active? and why? (Health related, social, economic etc)
d. Do you think it is not beneficial to be active and why? (getting tired, getting thin, waste of time)
Component – Barriers or facilitators to being active/participate in exercise
Question 2: What helps /do not help to participate in physical activity/exercise in your leisure time
before the exercise program?
Question 3: What helps /do not help to participate in the recently concluded exercise program?
Probes
a. Why did you start?
b. What is your stage of change when starting the program? (Thinking of exercising, not thinking of
exercising.)
c. What are your beliefs? And how does that effect the exercise adherence? ( about exercise,
about disease state and about the person who delivers)
d. Does Autonomy( ability to make your own decisions about the program) Your competence in
adhering to the program improve adherence
e. Does belonginess improved adherence
f. What were the limitations
o Lack of time?(why time not enough, what is your daily routine like)
o Lack of facilities? - reasons, suggestions,
o Accessibility, Travel
g. Lack of Motivation?-What motivates you ,lack of energy , studies, culture ,skills
h. Do you think support is important –(friends, family, society, institution)
i. Any Personal reasons Other (do not want to get tired, hurt, pain, sun, figure, just don’t like)
Component –Suggestions/ Recommendations
Question 4: How do you think we can improve physical activity among patients with DM and the
public?
Probes
a. In the workplace, study set up
b. During transport
c. At home
d. During leisure time
