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MODULE 3: NUTRITIONAL CONSIDERATIONS FOR EXERCISING INDIVIDUALS / ATHLETES
COMPONENTS OF ENERGY EXPENDITURE
What is metabolism?
Total amount of energy required for each of our physiological actions.
Difference between RMR and BMR?
BMR requires extreme fasting conditions, extended periods of rest, tight environmental control.
70% of energy we expend each day goes toward non movement related physiological activity.
Thermic effect of food
TEF is used for digestion, absorption and assimilation of ingested food/nutrients.
Act of eating increases metabolism BUT IT DEPENDS ON WHICH MACRONUTRIENTS we ingest.
Protein has highest TEF , Fat has lowest.
PHYSICAL ACTIVITY
High variable
sedentary - 10 to 15%
Highly active - 30 %
ESTIMATION OF ENERGY NEEDS
Measuring oxygen consumption can help measure energy cost
Direct mathematical relationship between amount of oxygen we breathe in and amount of energy required by the body
Burning of fuel mixture (CHO + Fat) provides 4.82 calories per litre of Oxygen.
Putting it into perspective....At rest, we burn 3.5 ml of oxygen / kg body weight /
minute
Person = 70 kg
Oxygen consumption per hour --- 3.5 x 70 x 60 = 14.7
Oxygen consumption per hour --- 14.7 x 24 = 352Therefore, Calories burnt = 3.52 x 4.82 = 1700 kcal
When exercise is added : breathing harder and faster ---- more oxygen --- therefore more calories burnt.
Oxygen consumption and energy expenditure are closely related!
ESTIMATION OF ENERGY EXPENDITURE
Indirect calorimetry
Estimation of EE via measurement of oxygen consumption and carbon dioxide production.
Direct calorimetry
Direct mesurement of heat output by the body, used as index of energy expenditure.
Double labeled waterThe Doubly Labelled Water (DLW) method uses the natural
occurring stable isotopes of water (D2O and H218O) to assess energy expenditure
The DLW method is entirely safe and non-restrictive, requires only periodic sampling of body fluids and is well suited for measurement of energy expenditure in free-living or hospitalized patients.
The basis of the DLW method is to follow the decline in enrichment of the stable isotopes of oxygen (oxygen-18, 18O) and hydrogen (deuterium, 2H) in body water after initial labeling of the body water pool.
As oxygen-18 is lost from the body in the form of water and carbon dioxide (CO2), whereas deuterium is lost only as water, the difference in loss from the body reflects the CO2 production during the period. Because CO2 production is the result of fat, carbohydrate and protein oxidation, it is an index of energy expenditure.
Bioelectrical impedance analysis
• This procedure involves sending a very small current through the body—800 mA at 50 kHz, which is unable to be felt—and measuring its resistance.
• The underlying theory to this procedure is :Lean tissue offers less resistance to a current as it contains more water and electrolytes than adipose tissue
• This is an affordable and non-invasive method. Another advantage of this procedure is that no special training or skill is required
Several factors may influence its results such as It quickly estimates the REE based on its estimation
hydration state of the subject, prandial/fasting state, exercises, diuretics use, menstrual period,
PREDICTIVE EQUATIONS
Mifflin-St Jeor (1990) in kcal/day
Male: (10 x W) + (6,25 x H) – (5 x A) + 5Female: (10 x W) + (6,25 x H) – (5 x A) – 161
W = Weight in KgH = Height in cmA = Age in years
Owen Equation
MenRMR (kcal/day) = 879 +10.2 (weight in kg)
Women:RMR (kcal/day) = 795 + 7.2 (weight in kg)
Harris and Benedict (1919) in kcal/day
Male 66.4730 + 13.7516(W) + 5.0033(H) – 6.7550(A)
Female 655.0955 + 9.5634(W) + 1.8496(H) – 4.6756(A)
Physical activities records:Low cost method that estimates EE from an extremely detailed registry off all physical activity studies is limited due to various existing codesperform daily
Dietary questionnaires
ENERGY AVAILABILTY
A new concept that is being promoted is that of energy availability—that is, the energy that is left for body functions once the energy cost of training is taken into account
There is evidence that the body can tolerate a certain level of reduction in energy intake, but energy availability lower than 30 kcal (126 kJ) per of lean body mass is associated with impairments of metabolic, hormonal, and reproductive function.
Definition of energy availability Total energy intake—energy cost of training
Example of low energy availabilityAthlete = 50 kg, distance runner, 10% body fatTraining programme = 1000 kcal/dayEnergy intake = 2250 kcal
Calculations: Body fat = 10% or 5 kgLean body mass (LBM) = 45 kgEnergy availability = 2250 -1000 = 1250 kcal= 1250/45 kg
= 28 kcal/kg LBM
Example of adequate energy availabilityAthlete = 60 kg distance runner, 10% body fatTraining program = 1000 kcal/dayEnergy intake = 3250 kcal
Calculations: Body fat = 10% or 6 kgLean body mass (LBM) = 54 kgEnergy availability = 3250 -1000 = 2250 kcal= 2250/54 kg
= 42 kcal/kg LBM
• POWER EVENTS OF HIGHER WEIGHT CATEGORY (80 KG AND ABOVE)
• ENDURANCE EVENTS
• TEAM EVENTS, ATHLETICS AND POWER EVENTS OF MIDDLE WEIGHT CATEGORY (65KG)
• EVENTS OF LIGHT WEIGHT CATEGORY
• SKILL GAMES
ACTIVITY - Categorize different sports according to the groupshttp://www.ilsi-india.org/PDF/Conf.%20recommendations/Nutrition/Nutrition%20&%20Hyd.%20Guidelines%20for
%20Athletes%20Final%20report.pdf
MARATHON, LONG DISTANCE RUNNING,
WALKING, HOCKEY, WEIGHT LIFTING,
WRESTLING, JUDO, ROAD CYCLING,
ROWING , SWIMMING, FOOT BALL, THROWING EVENTS
BASKETBALL, GYMNASTICS, TABLE TENNIS,
YATCHING, BOXING, VOLLEY BALL, SKILL
GAMES SHOOTING, ARCHERY , EQUESTRAIN,
Functions of macronutrients- in brief
MICRONUTRIENTS
• Micronutrients include vitamins and minerals.
• They do not provide energy.
• They are needed in small quantities.
• Deficiencies and excesses of the micronutrients can affect health
Functions of micronutrients- (brief)
VITAMIN METABOLIC ROLE
A Antioxidant function
Thiamin Carbohydrate metabolism
Riboflavin Mitochondrial electron transport
Niacin Multiple metabolic pathways
Pyridoxine Amino Acid synthesis
Folate Red blood cell synthesis
Cyanocobalamin Red blood cell synthesis
Ascorbic Acid Antioxidant, Tissue repair
D Calcium homeostasis, Immunity
MINERALS PROPOSED BENEFITSUMMARY OF RESEARCH FINDINGS
Calcium Important for forming bone and teeth, clotting blood, and transmitting nerve impulses.
Zinc Associated with immunity
Selenium Antioxidant.
Iron Helps to transport oxygen around the body