53
Dr Javier Gonzalez Department for Health, University of Bath, UK. [email protected] @Gonzalez_JT SHEDDING NEW LIGHT ON CARBOHYDRATES AND EXERCISE
Dr Javier Gonzalez
Department for Health,
University of Bath, UK.
j.t.go
nza
lez@
ba
th.a
c.u
k
@G
on
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lez_
JT
SHEDDING NEW LIGHT ON
CARBOHYDRATES AND EXERCISE
Energy Stores
FAT: >100,000 kcal
Van Loon (2012)
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Energy Stores
CHO: <3,200 kcal FAT: >100,000 kcal
Van Loon (2012)
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Res
t40 55 75
0
25
50
75
100
Exercise intensity(% Wmax)
Oxid
atio
n ra
te (kJ/m
in)
Muscle glycogen
(& plasma lactate)
Plasma glucose
Plasma NEFA
Other lipid sources
Fuels for Exercise
van Loon et al. (2001) J Physiol; Bosch et al. (1994) J Appl Physiol 76(6)
Jeukendrup et al. (1999) Am J Phyiol 276(4); Jeukendrup et al. (1999) J Physiol 515(2)
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0 100 200 3000
1
2
3
4
5
Muscle glycogen (mmol/kg ww)
Tim
e to
fa
tig
ue
(h
ou
rs) Low CHO
Mixed
High CHO
Muscle Glycogen & Endurance
Bergstrom et al. (1967) Acta Physiol Scand 71: 140
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0 100 200 3000
1
2
3
4
5
Muscle glycogen (mmol/kg ww)
Tim
e to
fa
tig
ue
(h
ou
rs) Low CHO
Mixed
High CHO
Muscle Glycogen & Endurance
Bergstrom et al. (1967) Acta Physiol Scand 71: 140
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0 100 200 3000
1
2
3
4
5
Muscle glycogen (mmol/kg ww)
Tim
e to
fa
tig
ue
(h
ou
rs) Low CHO
Mixed
High CHO
Muscle Glycogen & Endurance
Bergstrom et al. (1967) Acta Physiol Scand 71: 140
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What about the Liver?
Gonzalez et al. (2016) Am J Physiol 311: E543
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Carbohydrate Ingestion
Coyle et al. (1986) J Appl Physiol 61: 165
Liver
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Liver Glycogen & Endurance
Casey et al. (2000) Am J Physiol Endocrinol Metab 287:E65x
-60 -40 -20 0 20 40 6020
40
60
80
100
Delta liver glycogen content (g)
Tim
e to
fa
tig
ue
(m
in) r = 0.53
p < 0.05
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Nutrition for performance
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Glucose
SGLT1
GLUT2
Glucose
BLOODSTREAM
INTESTINAL LUMEN
INTESTINAL CELLS
Types of Carbohydrate
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Glucose
SGLT1
GLUT2
Glucose
BLOODSTREAM
INTESTINAL LUMEN
INTESTINAL CELLS
Glucose
Glucose Glucose
Glucose Glucose
Maximum rate ~60 g/h (~1 g/min)
Types of Carbohydrate
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Glucose
SGLT1 GLUT5
Fructose
GLUT2 GLUT2
Glucose Fructose
BLOODSTREAM
INTESTINAL LUMEN
INTESTINAL CELLS
Maximum rate ~105 g/h (~1.75 g/min)
Types of Carbohydrate
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Maximizing Carbohydrate Delivery
Jeukendrup (2010) Curr Opin Clin Nutr Metab Care 13(4)
Gray & Ingelfinger (1966) J Clin Invest 45(3)
Wallis & Wittekind (2013) Int J Sport Nutr Exerc Metab 23(6)
GLU + FRU
1.75 g/min
GLU
~1 g/min
GLU
+
FRU
Maximal exogenous
CHO oxidation:
Liver SUC =
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But isn’t fructose toxic?
Egli et al. (2013) Diabetes 62: 2259
<5%E
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But isn’t fructose toxic?
Egli et al. (2013) Diabetes 62: 2259
<5%E 30%E
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Egli et al. (2013) Diabetes 62: 2259
But isn’t fructose toxic?
<5%E 30%E 30%E
208 g/d (41 tsp)
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Participants
Age: 25 ± 1 y
VO2peak: 58 ± 1 mL/min/kg
Wpeak: 330 ± 9 W
Training volume: 12 ± 2 h/week
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Study Design
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MRS Scan
Liver Glycogen
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Muscle Glycogen
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0 30 90 60 120 150
Time (min)
180
MRS Scan
MRS Scan
150 ml 600 ml
Study Design
= Douglas bag sample
GLU or SUC or WAT (1.8 g/min)
Gonzalez et al. (2015)
Am J Physiol Endocrinol Metab 309(12):E1032
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Muscle Glycogen
WAT(n = 4)
GLU(n = 14)
SUC(n = 14)
0
50
100
150
Mu
scle
gly
co
ge
n
co
nce
ntra
tio
n (m
mo
l/L)
** *
Pre
Post
Gonzalez et al. (2015)
Am J Physiol Endocrinol Metab 309(12):E1032
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Muscle Glycogen
WAT(n = 4)
GLU(n = 14)
SUC(n = 14)
0
50
100
150
Mu
scle
gly
co
ge
n
co
nce
ntra
tio
n (m
mo
l/L)
** *
Pre
Post
Gonzalez et al. (2015)
Am J Physiol Endocrinol Metab 309(12):E1032
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Muscle Glycogen
WAT(n = 4)
GLU(n = 14)
SUC(n = 14)
0
50
100
150
Mu
scle
gly
co
ge
n
co
nce
ntra
tio
n (m
mo
l/L)
** *
Pre
Post
Gonzalez et al. (2015)
Am J Physiol Endocrinol Metab 309(12):E1032
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Liver Glycogen
WAT(n = 4)
GLU(n = 14)
SUC(n = 14)
0
100
200
300
400
500
Liv
er g
lyco
ge
n
co
nce
ntra
tio
n (m
mo
l/L
)
*
Pre
Post
Gonzalez et al. (2015)
Am J Physiol Endocrinol Metab 309(12):E1032
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Liver Glycogen
WAT(n = 4)
GLU(n = 14)
SUC(n = 14)
0
100
200
300
400
500
Liv
er g
lyco
ge
n
co
nce
ntra
tio
n (m
mo
l/L
)
*
Pre
Post
Gonzalez et al. (2015)
Am J Physiol Endocrinol Metab 309(12):E1032
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Liver Glycogen
WAT(n = 4)
GLU(n = 14)
SUC(n = 14)
0
100
200
300
400
500
Liv
er g
lyco
ge
n
co
nce
ntra
tio
n (m
mo
l/L
)
*
Pre
Post
Gonzalez et al. (2015)
Am J Physiol Endocrinol Metab 309(12):E1032
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Intramyocellular Lipid
WAT(n = 4)
GLU(n = 14)
SUC(n = 14)
0
5
10
Intra
myo
ce
llu
lar lip
id
co
nce
ntra
tio
n (
mm
ol/g
)
Pre
Post
Gonzalez et al. (2015)
Am J Physiol Endocrinol Metab 309(12):E1032
No difference in net carbohydrate or fat
utilisation…in muscle
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Blood Lactate
0 30 60 90 120 150 1800.0
0.5
1.0
1.5
2.0
2.5
Time (min)
Blo
od
la
cta
te
co
nce
ntra
tio
n (m
mo
l/L
)
GLU
SUC* *
* *
Gonzalez et al. (2015)
Am J Physiol Endocrinol Metab 309(12):E1032
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Plasma NEFA
0 30 60 90 120 150 1800.0
0.2
0.4
0.6
0.8
Time (min)
Pla
sm
a N
EF
A
co
nce
ntra
tio
n (m
mo
l/L
)
*
*GLU
SUC
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0
2500
5000
7500
10000
Trial
Ne
t su
bstra
te
utiliza
tion
(kJ)
P = 0.02
P = 0.01
GLU SUC
FATFAT
CHOCHO
Whole-body Substrate Utilization
Gonzalez et al. (2015)
Am J Physiol Endocrinol Metab 309(12):E1032
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Gut Discomfort 0 30 60 90 120 150 1806
8
10
12
14
16
18
20
RP
E
GLU
SUC
**
Time P < 0.0001Trial NSInteraction P < 0.05
0 30 60 90 120 150 1801
2
3
4
5
Time (min)
Gu
t dis
co
mfo
rt
GLU
SUC*
Time P < 0.0001Trial NSInteraction P < 0.01
Sucrose reduces gut
discomfort and RPE
Gonzalez et al. (2015)
Am J Physiol Endocrinol Metab 309(12):E1032
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Carbohydrates During Exercise
Carbohydrate ingestion prevents liver glycogen
depletion during endurance exercise
Sucrose ingestion increases whole-body
carbohydrate utilization during endurance exercise,
compared to glucose ingestion
When ample CHO (>1 g/min) is provided:
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PLAG
LU
GLU
+ F
RU
210
225
240
255
270
285
Trial
Po
we
r o
utp
ut (
W)
a
a
b
What about Performance?
Currell & Jeukendrup (2008) Med Sci Sports Exerc
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PLAG
LU
GLU
+ F
RU
210
225
240
255
270
285
Trial
Po
we
r o
utp
ut (
W)
a
a
b
Currell & Jeukendrup (2008) Med Sci Sports Exerc
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What about Performance?
PLAG
LU
GLU
+ F
RU
210
225
240
255
270
285
Trial
Po
we
r o
utp
ut (
W)
a
a
b
Currell & Jeukendrup (2008) Med Sci Sports Exerc
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What about Performance?
CHO during recovery @G
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Muscle Glycogen Repletion
Betts & Williams (2010) Sports Med 40(11):941.
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Liver Glycogen Repletion
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0
25
50
75
100
125
150
175
Glucose
Sucrose
0 120 300
**
Time (min)
Muscle
gly
cogen c
oncentration
(mm
ol/L)
Muscle Glycogen Recovery
Fuchs et al. (2016) J Appl Physiol
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0
25
50
75
100
125
150
175
Glucose
Sucrose
0 120 300
**
Time (min)
Muscle
gly
cogen c
oncentration
(mm
ol/L)
Muscle Glycogen Recovery
Fuchs et al. (2016) J Appl Physiol
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0
25
50
75
100
125
150
175
Glucose
Sucrose
0 120 300
**
Time (min)
Muscle
gly
cogen c
oncentration
(mm
ol/L)
Muscle Glycogen Recovery
Fuchs et al. (2016) J Appl Physiol
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Liver Glycogen Recovery
0 120 3000
25
50
75
100
Glucose
Sucrose
*
*
#
Time (min)
Liv
er gly
cogen c
onte
nt
(g)
#
Fuchs et al. (2016) J Appl Physiol
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Liver Glycogen Recovery
0 120 3000
25
50
75
100
Glucose
Sucrose
*
*
#
Time (min)
Liv
er gly
cogen c
onte
nt
(g)
#
Fuchs et al. (2016) J Appl Physiol
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Liver Glycogen Recovery
0 120 3000
25
50
75
100
Glucose
Sucrose
*
*
#
Time (min)
Liv
er gly
cogen c
onte
nt
(g)
#
Fuchs et al. (2016) J Appl Physiol
0
10
20
30
40
50
60
70
#
#Sucrose
Glucose
Time (min)
30027024021018030 9060 120
Nausea
(AU
)
Nausea @G
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Fuchs et al. (2016) J Appl Physiol
Carbohydrates for Recovery
Glucose-fructose mixtures result in less gut
discomfort than glucose ingestion only
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When ample CHO (>1.2 g/kgBM/h) is provided:
Glucose-fructose mixtures accelerate liver, but not
muscle glycogen repletion rates compared to
glucose ingestion only
Unresolved questions @G
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Gonzalez et al. (2016) Am J Physiol 311: E543
What is the minimum amount of carbohydrate
required to prevent liver glycogen depletion
during exercise?
What is the optimum amount and type of
nutrition for post-exercise liver glycogen
recovery?
Summary
Carbohydrate ingestion prevents liver glycogen
depletion, maintains blood glucose concentration
and carbohydrate oxidation
Glucose-fructose mixtures increase carbohydrate
availability and alleviate gut discomfort during
exercise
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Glucose-fructose mixtures double liver glycogen
repletion rates, relative to glucose only, with lower
gut discomfort
Take Home Messages @G
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To maintain optimal endurance performance during
prolonged, endurance-type exercise, consider
ingesting a mixture of glucose + fructose (sucrose)
at a rate of 30-90 g/h.
To accelerate acute post-exercise recovery
consider ingesting a mixture of glucose + fructose
(sucrose) at a rate of 1.2 g/kgBM/h.
Acknowledgements @G
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