The importance of Carbohydrates explained.

1. Carbohydrates
in
Exercise
and
Recovery
Rookie
version

2. Outline
I.
Carbohydrates:
Defini7ons,
diges7on,
absorp7on
A.
Carbohydrates
in
the
diet
B.
Diges7on
and
absorp7on
of
carbohydrates
C.
Carbohydrate
metabolism
D.
Glycogen—storage
of
carbohydrates
in
the
body
II.
Proper7es
of
carbohydrates:
Considera7ons
for
sports
performance
A.
Glycemic
index
B.
Glycemic
load
C.
High-­‐fructose
corn
syrup
III.
Training
A.
Carbohydrates
before
exercise
B.
Carbohydrates
during
exercise
C.
Recovery
D.
Meal
planning
IV.
Compe77on
A.
Carbohydrate
loading
B.
Pre-­‐compe77on
meals
C.
Carbohydrates
during
compe77on

3. I.
Carbohydrates:
Defini7ons,
Diges7on,
Absorp7on,
and
Storage

4. Carbohydrates
in
Sports
Nutri=on
§ Carbohydrates
(CHOs)
are
a
major
fuel
source
for
exercising
muscle,
especially
in
high-­‐intensity
or
long-­‐dura7on
ac7vi7es
§ Carbohydrates
can
influence
fluid
absorp7on
from
the
intes7ne
(hydra7on)
§ Some
CHOs
can
cause
gastrointes7nal
intolerance
and
thereby
impair
exercise
performance
§ Types
of
CHOs
– Exogenous:
CHO
intake
from
the
diet
– Endogenous:
CHO
stored
in
the
body
(ie,
glycogen)
that
can
be
used
for
energy
needs
§ Glycogen
is
stored
glucose
in
the
body
– It
is
a
network
of
glucose
molecules
connected
together,
similar
to
starch
United
States
An7-­‐doping
Agency.
Op7mal
dietary
intake
guide.
Available
at:
hTp://www.usada.org/diet/?gclid=COOM-­‐Ky95aYCFQTNKgodzVQL2w.
Accessed
January
31,
2011.

5. Carbohydrates
in
Diet
Carbohydrates
are
found
in
the
diet
as
1.
Free
monosaccharides
(1
sugar
unit)
• Glucose
(aka
dextrose,
from
corn
and
other
plants)
• Fructose
(from
fruit)
• Galactose
(from
milk)
2.
Di-­‐,
tri-­‐,
oligo-­‐
(4
to
10
units),
or
polysaccharides
(chain
of
11+
monosaccharides)
• Sucrose
(disaccharide
of
glucose
+
fructose)
• Lactose
(disaccharide
of
glucose
+
galactose)
• Maltose
(disaccharide
of
2
glucose
molecules)
• Trehalose
(disaccharide
of
2
glucose
molecules,
with
a
different
linkage
between
the
two)
• Starch
(polysaccharide
of
glucose)
Berg
JM,
et
al.
Biochemistry.
5th
ed.
New
York,
NY:
WH
Freeman
and
Co;
2002.

6. Carbohydrate
Diges=on
§ Carbohydrates
are
absorbed
as
monosaccharides
§ Enzymes
must
digest
di-­‐,
tri-­‐,
oligo-­‐,
and
polysaccharides
into
individual
monosaccharides
– Enzymes
exist
in
the
saliva,
stomach,
and
small
intes7ne
to
break
the
different
linkages
between
the
various
sugars
§ There
are
special
transporters
in
the
cell
membranes
of
intes7nal
cells
that
selec7vely
absorb
monosaccharides
– Monosaccharides
are
then
transported
into
the
blood
stream,
where
they
are
distributed
throughout
the
body
§ Carbohydrates
that
escape
diges7on
and
absorp7on
make
their
way
to
the
colon
(with
variable
degrees
of
bacterial
fermenta7on)
Holmes
R.
J
Clin
Pathol.
1971;5(suppl):10-­‐13.

7. Why
Is
Carbohydrate
Absorp=on
Important
in
Sports
Nutri=on?
§ The
ability
of
the
intes7ne
to
absorb
a
carbohydrate
can
be
the
rate-­‐limi7ng
step
for
its
delivery
to
muscle
cells
for
fuel
use
§ Enzyme
systems
in
the
intes7ne
may
be
insufficient
to
digest
some
carbohydrates
(eg,
lactose
intolerance)
§ Intes7nal
sugar
transporters
can
become
saturated,
resul7ng
in
malabsorp7on
of
a
carbohydrate
§ There
are
mul7ple
transporters
for
carbohydrates
– Ingest
a
blend
of
sugars
that
require
different
intes7nal
transporter
systems
(ie,
glucose
and
fructose)
• Avoids
satura7on
of
any
one
transporter
– May
increase
carbohydrate
absorp7on
rela7ve
to
using
just
a
single
sugar

8. Progress
Check—Defini=ons,
Diges=on,
Absorp=on,
and
Storage
1. Carbohydrates
are
absorbed
in
the
intes7ne
as
which
of
the
following?
A. Monosaccharides
B. Disaccharides
C. Polysaccharides
D. All
of
the
above
2. Carbohydrates
can
influence
fluid
absorp7on
from
the
intes7ne
(hydra7on).
A. True
B. False
3. Which
carbohydrate
statement
is
NOT
true?
A. Carbohydrate
absorp7on
can
be
a
rate-­‐limi7ng
step
in
delivering
fuel
to
muscles
B. Carbohydrates
can
be
digested
by
enzymes
in
the
saliva,
stomach,
and
small
intes7nes
C. All
sugars
are
all
absorbed
from
the
intes7nes
by
a
single
type
of
transporter
D. Carbohydrates
can
be
a
cause
of
gastrointes7nal
intolerance
that
can
nega7vely
affect
exercise
performance
8

9. Progress
Check—Defini=ons,
Diges=on,
Absorp=on,
and
Storage
1. Carbohydrates
are
absorbed
in
the
intes7ne
as
which
of
the
following?
A. Monosaccharides
Correct,
carbohydrates
are
absorbed
as
monosaccharides.
B. Disaccharides
Incorrect,
please
review
slide
Carbohydrate
Diges:on
to
be;er
understand
carbohydrate
absorp:on.
C. Polysaccharides
Incorrect,
please
review
slide
Carbohydrate
Diges:on
to
be;er
understand
carbohydrate
absorp:on.
D. All
of
the
above
Incorrect,
please
review
slide
Carbohydrate
Diges:on
to
be;er
understand
carbohydrate
absorp:on.
9

û
û
û

10. Progress
Check—Defini=ons,
Diges=on,
Absorp=on,
and
Storage
2. Carbohydrates
can
influence
fluid
absorp7on
from
the
intes7ne
(hydra7on).
A. True
Correct,
carbohydrates
can
influence
hydra:on.
B. False
Incorrect,
please
review
slide
Carbohydrates
in
Sports
Nutri:on
to
be;er
understand
the
effects
of
carbohydrates
on
the
intes:nes.
10
û


11. Progress
Check—Defini=ons,
Diges=on,
Absorp=on,
and
Storage
3. Which
carbohydrate
statement
is
NOT
true?
A. Carbohydrate
absorp7on
can
be
a
rate-­‐limi7ng
step
in
delivering
fuel
to
muscles
Incorrect,
please
review
slide
Why
Is
Carbohydrate
Absorp:on
Important
in
Sports
Nutri:on?
to
be;er
understand
the
roles
that
carbohydrates
have
in
the
body.
B. Carbohydrates
can
be
digested
by
enzymes
in
the
saliva,
stomach,
and
small
intes7nes
Incorrect,
please
review
slide
Carbohydrate
Diges:on
to
be;er
understand
carbohydrate
diges:on.
C. All
sugars
are
all
absorbed
from
the
intes7nes
by
a
single
type
of
transporter
Correct,
only
a
single
type
of
transporter
can
absorb
carbohydrates
in
the
intes:ne.
D. Carbohydrates
can
be
a
cause
of
gastrointes7nal
intolerance
that
can
nega7vely
affect
exercise
performance
Incorrect,
please
review
slide
Why
Is
Carbohydrate
Absorp:on
Important
in
Sports
Nutri:on?
to
be;er
understand
the
roles
that
carbohydrates
have
in
the
body.
11

û
û
û

12. Carbohydrate
Metabolism
Electron
transport
chain
Glucose
CO2
Pyruvate oxidation
Krebs cycle
(aka tricarboxylic acid
or TCA cycle)
ATP
energy
Galactose
Fructose
Glycolysis
GlycogenGlucose
intermediate
Berg
JM,
et
al.
Biochemistry
.5th
ed.
New
York,
NY:
WH
Freeman
and
Co.;
2002.

13. Storage
of
Carbohydrate
in
the
Body
§ If
glucose
is
absorbed,
but
not
needed
right
away,
the
body
stores
a
small
amount
as
glycogen
– Glycogen
is
a
fluctua7ng
storage
pool
for
glucose
– The
structure
of
glycogen
is
similar
to
starch
– Found
in
the
liver
and
skeletal
muscles
• Glycogen
in
liver
is
a
reserve
glucose
supply
to
the
brain
• Glycogen
in
muscles
is
an
energy
source
for
exercise
– Glucose
from
glycogen
breakdown
does
not
leave
the
muscles
Berg
JM,
et
al.
Biochemistry
.5th
ed.
New
York,
NY:
WH
Freeman
and
Co.;
2002.

14. Glycogen
During
Exercise
§ During
exercise,
glycogen
is
broken
down
and
glucose
molecules
enter
glycolysis
(ie,
energy
metabolism)
§ Vitamin
B6
is
a
structural
part
of
the
enzyme
that
breaks
down
glycogen
– Shows
one
of
the
many
roles
of
B-­‐vitamins
in
energy
metabolism
§ Glycogen
can
supply
the
body
with
only
a
limited
amount
of
energy
– Exogenous
carbohydrates
are
important
for
high-­‐intensity
and
long-­‐
dura7on
exercise
§ Eat
carbohydrates
immediately
aper
exercise
for
most
rapid
glycogen
replenishment
(recovery)
– Inges7on
of
50
grams
of
carbohydrate
every
2
hours
can
result
in
up
to
5%
glycogen
replacement
per
hour
• Therefore,
total
replacement
would
take
20
hours
Hui
YH.
Handbook
of
Food
Science,
Technology,
and
Engineering.
Volume
1.
Boca
Raton,
FL:
CRC
Press;
2006:10-­‐12.
United
States
An7-­‐doping
Agency.
Op7mal
dietary
intake
guide.
Available
at:
hTp://www.usada.org/diet/?gclid=COOM-­‐Ky95aYCFQTNKgodzVQL2w.
Accessed
January
31,
2011.
Tardie
G.
The
Sports
Journal.
Available
at:
hTp://www.thesportjournal.org/ar7cle/glycogen-­‐replenishment-­‐aper-­‐exhaus7ve-­‐exercise.
Accessed
February
17,
2011.

15. Progress
Check—Defini=ons,
Diges=on,
Absorp=on,
and
Storage
1. Which
of
the
following
is
referred
to
as
“animal
starch”?
A. Glycose
B. Glycogen
C. Trehalose
D. Galactose
2. Muscle
glycogen
levels
can
be
broken
down
to
supply
glucose
for
the
bloodstream
when
blood
glucose
is
low.
A. True
B. False
15

16. Progress
Check—Defini=ons,
Diges=on,
Absorp=on,
and
Storage
1. Which
of
the
following
is
referred
to
as
“animal
starch”?
A. Glycose
Incorrect,
please
review
slide
Storage
of
Carbohydrate
in
the
Body
to
be;er
understand
carbohydrate
storage.
B. Glycogen
Correct,
the
structure
of
glycogen
is
similar
to
starch
in
plants.
C. Trehalose
Incorrect,
please
review
slide
Storage
of
Carbohydrate
in
the
Body
to
be;er
understand
carbohydrate
storage.
D. Galactose
Incorrect,
please
review
slide
Storage
of
Carbohydrate
in
the
Body
to
be;er
understand
carbohydrate
storage.
16

û
û
û

17. Progress
Check—Defini=ons,
Diges=on,
Absorp=on,
and
Storage
2. Muscle
glycogen
levels
can
be
broken
down
to
supply
glucose
for
the
bloodstream
when
blood
glucose
is
low.
A. True
Incorrect,
please
review
slide
Glycogen
During
Exercise
to
be;er
understand
the
use
of
glycogen
in
the
body.
B. False
Correct,
glucose
from
muscle
glycogen
breakdown
does
not
leave
the
muscles.
17
û


18. II.
Proper=es
of
Carbohydrates:
Considera7ons
for
Sports
Performance

19. Glycemic
Response
to
Carbohydrates
in
Sports
Nutri=on
§ Inges7on
of
carbohydrates
affects
both
blood
glucose
levels
and
insulin
response
(glycemic
response)1
– Can
influence
energy
sources
during
exercise
§ One
measure
of
glycemic
response
is
the
glycemic
index
(GI)2,3
§ Glycemic
load
is
a
rela7vely
new
measure
for
glycemic
response4
– Based
on
the
concept
that
exercise
performance
may
be
determined
by
both
carbohydrate
inges7on
and
the
glycemic
response
of
the
overall
diet
19
1.
Mondazzi
L
and
Arcelli
E.
J
Am
Coll
Nutr.
2009;28:455S-­‐463S.
2.
Burke
LM,
et
al.
Int
J
Sport
Nutr.
1998;8:401-­‐415.
3.
Donaldson
CM,
et
al.
Int
J
Sport
Nutr
Exerc
Metab.
2010;20:154-­‐165.
4.
O’Reilly
J,
et
al.
Sports
Med.
2010;40:27-­‐39.

20. What
Is
the
Glycemic
Index?
§ System
of
ranking
foods
according
to
how
much
they
raise
blood
glucose
rela7ve
to
a
reference
food
– Developed
by
Jenkins
DJ,
et
al.
Am
J
Clin
Nutr.
1981;34(3):362-­‐366.
§ Rapidly
digested
or
absorbed
carbohydrates
=
high
GI
§ Slowly
digested
or
absorbed
carbohydrates
=
low
GI
§ References
on
GI
– Brand-­‐Miller
J,
et
al.
The
New
Glucose
RevoluJon.
3rd
ed.
New
York,
NY:
Marlowe
&
Co.;
2006
• WriTen
by
experts
on
GI
– Atkinson,
et
al.
Diabetes
Care.
2008;31(12):2281-­‐2283
• Most
comprehensive
table
of
the
glycemic
index
of
foods
that
has
been
assembled
to
date
Abbrevia7ons:
GI,
glycemic
index.
Figure
from
hTp://www.glycemicindex.com/aboutGI.htm.

21. What
Does
the
Glycemic
Index
Value
Mean?
§ The
glycemic
index
(GI)
is
expressed
as
a
ra7o
comparing
the
blood
glucose
increase
caused
by
a
test
food
to
that
of
a
reference
food
(usually
glucose,
historically
white
bread)
for
2
hours
following
inges7on:
§ GI
values:
Split
peas
=
25
±
6
Golden
delicious
apples
=
39
±
3
Oatmeal
=
51
±
8
Raisin
bran
flake
type
of
cereal
=
61
±
5
White
bread
=
75
±
2
Long-­‐grain
white
rice
=
76
±
7
Corn
flake
type
of
cereal
=
81
±
3
Atkinson
FS,
et
al.
Diabetes
Care.
2008;31(12):2281-­‐2283.
Area
Under
the
Curve
for
Test
Food
Area
Under
the
Curve
for
Reference
Food
×
100
=
GI

22. Slow
and
Fully
Digested
CHOs
(Low
GI)
§ Isomaltulose1
– Glucose
and
fructose
– More
steady
and
sustained
release
of
glucose
into
the
blood
compared
with
sucrose
– Occurs
naturally
in
honey,
but
can
be
synthesized
from
sucrose
§ Sucromalt2
– Produced
by
enzyma7c
conversion
of
sucrose
and
maltose
into
a
fructose
and
oligosaccharide
syrup
• ~40%
fructose,
~50%
oligosaccharides,
and
~10%
other
mono-­‐
and
disaccharides
– Diges7on
profile
similar
to
isomaltulose
§ Gamma-­‐cyclodextrin
(γ-­‐CD)3
– Ring
of
8
glucose
molecules
+
Abbrevia7ons:
CHO,
carbohydrate;
GI,
glycemic
index.
1.
Lina
BA,
et
al.
Food
Chem
Toxicol.
2002;40(10):1375-­‐1381.
2.
Xtend™
Sucromalt.
Cargill,
Inc.
Available
at:
hTp://www.cargill.com/food/na/en/products/sweeteners/specialty-­‐sweeteners/xtend-­‐sucromalt/index.jsp.
Accessed
February
24,
2011.
3.
Munro
IC,
et
al.
Regul
Toxicol
Pharmacol.
2004;39:S3-­‐13.

23. What
Is
the
Glycemic
Load?
§ Takes
into
account
the
amount
of
carbohydrate
in
a
common
serving
in
addi7on
to
its
glycemic
index
§ Example
– Carrots
(peeled,
boiled)
have
a
GI
of
47
and
5
g
CHO
per
serving
The
GL
of
carrots
is:
(47
×
5)
÷
100
=
2.4
GL
=
(GI
of
CHO
×
gram
CHO
per
serving)
÷
100
Abbrevia7ons:
CHO,
carbohydrate;
GL,
glycemic
load;
GI,
glycemic
index.
Atkinson
FS,
et
al.
Diabetes
Care.
2008;31(12):2281-­‐2283.

24. Glycemic
Index
and
Load
Standards
for
Foods
§
GI
(based
on
glucose
reference)
– Low
GI
0-­‐55
– Intermediate
GI
56-­‐69
– High
GI
≥
70
§ GL
– Low
GL
0-­‐10
– Intermediate
GL
11-­‐19
– High
GL
≥
20
Abbrevia7ons:
GI,
glycemic
index;
GL,
glycemic
load.
Brand-­‐Miller
J,
et
al.
The
New
Glucose
RevoluJon:
The
AuthoritaJve
Guide
to
the
Glycemic
Index-­‐The
Dietary
SoluJon
for
Lifelong
Health.
3rd
ed.
New
York,
NY:
Marlowe
and
Co.;
2006.
Brand-­‐Miller
JC,
et
al.
Am
J
Clin
Nutr.
2003;77(4):993-­‐995.

25. Limita=ons
of
Glycemic
Index
During
Exercise
§ Clinical
data
have
been
mixed
regarding
the
role
of
the
glycemic
index
(GI)
in
food
choice
before
exercise
– Results
suggest
that
inges7on
of
foods
with
a
low
GI
before
exercise
may
• ATenuate
the
glycemic
response
• Maintain
carbohydrate
availability
during
exercise
§ Clinical
results
also
suggest
that
moderate
to
high
GI
foods
may
aid
in
carbohydrate
availability
when
ingested
during
exercise
§ Differen7al
inges7on
of
low
vs
high
GI
foods
before
or
during
exercise
has
not
yet
translated
into
clear
performance
benefits
25
Burke
LM,
et
al.
Int
J
Sport
Nutr.
1998;8:401-­‐415.
Donaldson
CM,
et
al.
Int
J
Sport
Nutr
Exerc
Metab.
2010;20:154-­‐165.

26. What
Is
High-­‐Fructose
Corn
Syrup?
§ Cornstarch
is
converted
to
corn
syrup
that
is
essen7ally
100%
glucose
§ Enzymes
and
processing
techniques
convert
some
of
the
glucose
to
fructose
to
achieve
corn
syrup
that
is
55%
fructose
(HFCS-­‐55)
§ HFCS-­‐55
is
the
type
of
corn
syrup
used
mainly
in
the
beverage
industry
– Syrup
is
55%
fructose,
45%
glucose
– Similar
to
sucrose
(table
sugar;
50%
fructose,
50%
glucose)
§ The
term
“high-­‐fructose
corn
syrup”
is
a
liTle
misleading
– Because
corn
syrup
is
100%
glucose,
any
presence
of
fructose
typically
results
in
it
being
labeled
“high-­‐fructose
corn
syrup”
Soenen
S,
et
al.
Am
J
Clin
Nutr.
2007;86(6):1586-­‐1594.
Smith
JS,
et
al.
Food
Processing:
Principles
and
ApplicaJons.
Ames,
IA:
Blackwell
Publishing;
2004:212-­‐214.

27. The
Truth
About
High-­‐Fructose
Corn
Syrup
§ Too
much
sugar,
of
any
kind,
in
beverages
is
not
recommended
– It
is
easy
to
consume
too
much
energy,
leading
to
weight
gain
– Most
sugar-­‐sweetened
beverages
provide
liTle
to
no
vitamins,
minerals,
or
other
essen7al
nutrients
§ However,
there
are
no
differences
in
metabolic
responses
to
high-­‐fructose
corn
syrup
vs
sucrose
in
humans
– No
differences
in
circula7ng
hormones
– No
differences
in
appe7te
or
sa7ety-­‐related
variables
(fullness)
DiMeglio
DP,
et
al.
Int
J
Obesity.
2000;24:794-­‐800.
Melanson
KJ,
et
al.
NutriJon.
2007;23(2):103-­‐112.
Stanhope
KL,
et
al.
Am
J
Clin
Nutr.
2008;87(5):1194-­‐1203.
Soenen
S,
et
al.
Am
J
Clin
Nutr.
2007;86(6):1586-­‐1594.

28. Progress
Check—Considera=ons
for
Sports
Performance
1. Inges7on
of
low
versus
high
glycemic
index
foods
before
or
during
exercise
has
clear
performance
benefits.
A. True
B. False
2. Glycemic
load
is
based
on
which
of
the
following
concepts?
A. Only
carbohydrate
inges7on
determines
exercise
performance
B. Only
the
glycemic
response
of
the
overall
diet
determines
exercise
performance
C. Both
the
amount
of
carbohydrate
per
serving
and
the
glycemic
index
of
that
carbohydrate
influence
the
blood
glucose
response
D. Stored
glycogen
in
muscles
determines
exercise
performance
3. In
humans,
metabolic
responses
to
high-­‐fructose
corn
syrup
are
similar
to
which
of
the
following?
A. Glucose
B. Glycogen
C. Fructose
D. Sucrose
28

29. Progress
Check—Considera=ons
for
Sports
Performance
1. Inges7on
of
low
versus
high
glycemic
index
foods
before
or
during
exercise
has
clear
performance
benefits.
A. True
Incorrect,
please
review
slide
Limita:ons
of
Glycemic
Index
During
Exercise
to
be;er
understand
the
effects
of
glycemic
index
foods
on
performance
during
exercise.
B. False
Correct,
intake
of
low
versus
high
glycemic
index
foods
before
or
during
exercise
has
not
shown
clear
performance
benefits.
29
û


30. Progress
Check—Considera=ons
for
Sports
Performance
2. Glycemic
load
is
based
on
which
of
the
following
concepts?
A. Only
carbohydrate
inges7on
determines
exercise
performance
Incorrect,
please
review
slide
What
Is
the
Glycemic
Load?
to
be;er
understand
the
calcula:on
and
defini:on
of
glycemic
load.
B. Only
the
glycemic
response
of
the
overall
diet
determines
exercise
performance
Incorrect,
please
review
slide
What
Is
the
Glycemic
Load?
to
be;er
understand
the
calcula:on
and
defini:on
of
glycemic
load.
C. Both
the
amount
of
carbohydrate
per
serving
and
the
glycemic
index
of
that
carbohydrate
influence
the
blood
glucose
response
Correct,
both
amount
and
glycemic
index
of
carbohydrates
influence
glucose
response.
D. Stored
glycogen
in
muscles
determines
exercise
performance
Incorrect,
please
review
slide
What
Is
the
Glycemic
Load?
to
be;er
understand
the
calcula:on
and
defini:on
of
glycemic
load.
30

û
û
û

31. Progress
Check—Considera=ons
for
Sports
Performance
3. In
humans,
metabolic
responses
to
high-­‐fructose
corn
syrup
are
similar
to
which
of
the
following?
A. Glucose
Incorrect,
please
review
slide
The
Truth
About
High-­‐Fructose
Corn
Syrup
to
be;er
understand
the
body’s
response
to
high-­‐fructose
corn
syrup.
B. Glycogen
Incorrect,
please
review
slide
The
Truth
About
High-­‐Fructose
Corn
Syrup
to
be;er
understand
the
body’s
response
to
high-­‐fructose
corn
syrup.
C. Fructose
Incorrect,
please
review
slide
The
Truth
About
High-­‐Fructose
Corn
Syrup
to
be;er
understand
the
body’s
response
to
high-­‐fructose
corn
syrup.
D. Sucrose
Correct,
the
body
metabolizes
high-­‐fructose
corn
syrup
similarly
to
sucrose.
31

û
û
û

32. III.
Training

33. Carbohydrates
and
Sports
Nutri=on
§ Important
for
maximizing
muscle
glycogen
stores
– Depleted
muscle
glycogen—“Hi}ng
the
wall”
– Depleted
liver
glycogen—“Bonking”
– Both
phenomena
are
experienced
as
a
precipitous
loss
of
energy
as
a
result
of
low
blood
sugar
§ Training
and
high
carbohydrate
diets
maximize
glycogen
stores
United
States
An7-­‐doping
Agency.
Op7mal
dietary
intake
guide.
Available
at:
hTp://www.usada.org/diet/?gclid=COOM-­‐Ky95aYCFQTNKgodzVQL2w.
Accessed
January
31,
2011.
Ensminger
A.
Foods
and
NutriJon
Encyclopedia
2nd
EdiJon
Volume
1.
Boca
Raton,
FL:
CRC
Press
LLC;
1994.
Pages
1202-­‐1203.
Burke
L.
PracJcal
Sports
NutriJon.
Champaign,
IL:
Human
Kine7cs;
2007.
Page
124.
Clark
N.
Sports
NutriJon
Guidebook
4th
EdiJon.
Champaign,
IL:
Human
Kine7cs;
2008.
Page
119.

34. Carbohydrate
and
Fat
Use
at
Different
Exercise
Intensi=es
§ As
the
intensity
of
exercise
increases,
muscle
glycogen
cons7tutes
a
greater
por7on
of
the
energy
source
Abbrevia7ons
FFA,
free
faTy
acid.
Romijn
JA,
et
al.
Am
J
Physiol.
1993;265(Part
1):E380-­‐E391.
(Weightlifting,
sprinting, etc)
(Leisurely walking,
slow cycling)
(Soccer,
dancing, etc) Muscle
glycogen
Muscle
triglyceride
Plasma
FFA
Plasma
glucose
300
200
100
0
Energy
Expended,
cal/kg/min
25
65
85
Maximal
Oxygen
Consump=on,
%

35. Carbohydrates
in
the
Days
Before
Exercise
§ High
glycogen
stores
are
very
important
to
prolong
endurance
– Related
to
diet
and
exercise
in
the
days
and
hours
before
exercising/
compe7ng
– Endogenous
carbohydrate
oxida7on
occurs
at
high
intensity
– Especially
important
for
events
longer
than
90-­‐120
minutes
(eg,
marathons
and
cycling
events)
United
States
An7-­‐doping
Agency.
Op7mal
dietary
intake
guide.
Available
at:
hTp://www.usada.org/diet/?gclid=COOM-­‐Ky95aYCFQTNKgodzVQL2w.
Accessed
January
31,
2011.
LaTa
S.
Marathon
&
Beyond.
2003;7(5).

36. Carbohydrates
1
to
2
Hours
Before
Exercise
§ Low
glycemic
index
foods
and
beverages
– Especially
important
for
endurance
exercise
§ Carbohydrates
that
are
also
low
in
fiber
may
be
beneficial
due
to
varied
gastrointes7nal
sensi7vity
among
individuals
– Examples
• Fruit
juices
• Bagels
• Breakfast
cereals
with
<
3
g
fiber/serving
• Potatoes
§ Carbohydrate
amounts
vary
among
individuals,
sport
type,
and
sport
intensity
United
States
An7-­‐doping
Agency.
Op7mal
dietary
intake
guide.
Available
at:
hTp://www.usada.org/diet/?gclid=COOM-­‐Ky95aYCFQTNKgodzVQL2w.
Accessed
January
31,
2011.
Wu
CL
and
Williams
C.
Int
J
Sport
Nutr
Exerc
Metab.
2006;16(5):510-­‐527.

37. Carbohydrates
During
Exercise
Are
Also
Important
§ Jeukendrup
(2004)
reviewed
mul7ple
studies
(n
=
22)
of
walking,
running,
and
cycling
in
which
carbohydrates
were
given
during
exercise
– 23
of
36
observa7ons
within
these
studies
showed
a
posi7ve
effect
of
carbohydrate
on
endurance
– Effec7ve
dose
• Minimum,
16
to
22
g
carbohydrate/hour
• Maximum,
75
g
carbohydrate/hour
– No
studies
showed
an
adverse,
or
ergoly7c,
effect
of
carbohydrate
on
performance
– Form
of
carbohydrate
(solid
or
liquid)
was
of
liTle
significance,
although
the
vast
majority
of
the
studies
used
a
beverage
§ Sports
beverages
that
include
different
types
of
sugars
will
be
absorbed
via
different
sugar
transporters
in
the
gut
– Increase
exogenous
carbohydrate
oxida7on
during
exercise
from
1.0
g/min
to
1.2
to
1.5
g/min
Jeukendrup
AE.
NutriJon.
2004;20(7-­‐8):669-­‐677.

38. Carbohydrates
Afer
Exercise
§ Carbohydrates
that
are
quickly
digested
and
absorbed
are
recommended
postexercise
to
restore
muscle
glycogen
levels
as
fast
as
possible
– Glucose
– Maltose
– Maltodextrin
§ Protein
+
carbohydrates
postexercise
maximizes
the
rate
of
glycogen
synthesis
§ When
intervals
between
exercise
sessions
are
<
8
hours,
consume
carbohydrates
as
soon
as
prac7cal
postexercise
for
fastest
recovery
Ivy
JL,
et
al.
J
Appl
Physiol.
2002;93:1337-­‐1344.

39. Recommenda=ons
for
Carbohydrate
Intake
During
Recovery
§ Carbohydrate
intakes
are
expressed
per
kga
not
%
of
energy
– For
immediate
recovery
aper
exercise
(0
to
4
hours)
• 1.2
g/kg/hr
consumed
at
frequent
intervals
– For
daily
recovery
• Moderate
dura7on/low
intensity
exercise
– 5
to
7
g/kg/day
• Moderate
to
heavy
endurance
training
– 7
to
12
g/kg/day
• Extreme
exercise
program
(≥
4
to
6
hours/day)
– 10
to
12+
g/kg/day
aMul7ply
the
numbers
by
0.45
to
get
carbohydrate
intake
in
grams
per
pound
of
body
weight.
Burke
LM,
et
al.
J
Sport
Sci.
2004;22(1):15-­‐30.

40. Pugng
Together
a
Meal
Plan
§ Example:
– 70-­‐kg
athlete
requiring
4000
kcal/day
and
exercising
120
min/day
4
to
6
7mes/week
§ Macronutrient
Target
Recommenda7ons
– Grams/kg
(body
weight)/day
• Carbohydrate
7
to
10
g/kg/day
(490
to
700
g/day)
• Protein
1.5
to
2.0
g/kg/day
(105
to
140
g/day)
• Fat
Typically
use
percentage
of
energy
as
method
– Percentage
of
energy
• Carbohydrate
55%
to
65%
of
energy
(550
to
650
g/day)
• Protein
10%
to
15%
of
energy
(100
to
150
g/day)
• Fat
20%
to
30%
of
energy
(88
to
133
g/day)
– Target
recommenda7ons
for
this
athlete
• Carbohydrate
600
g
(60%
of
energy)
• Protein
130
g
(13%
of
energy)
• Fat
120
g
(27%
of
energy)

41. A
Poten=al
Distribu=on
of
Macronutrients
Over
the
Course
of
6
Meals/Day
Meal Time Carbohydrate,
g Protein,
g Fat,
g
Breakfast 7:00
AM 90 15 15
Mid-­‐AM
snack 10:00
AM 25 10 5
Lunch Noon 75 20 20
Pre-­‐Ex
meal 1:30
-­‐
2:00
PM 90 10 5
During
Ex 3:00
-­‐
5:00
PM 100 0 0
Post-­‐Ex
meal 5:00
PM 75 30 25
Dinner 6:30
PM 120 30 35
PM
snack 9:00
PM 25 15 15
TOTALS 600 130 120

42. Foods
Containing
Approximately
25
to
30
g
Carbohydrate
§ 1
cup
of
juice
or
1
large
piece
of
fruit
§ 1
bagel
or
2
slices
of
bread
§ 1
cup
of
most
cereals
§ 1
large
baked
potato
§ 2
cups
of
milk
§ ⅔
cup
of
dried
beans
§ 1
cup
of
rice
or
corn
§ 1
cup
of
squash
(other
non-­‐starchy
vegetables
have
less
carbohydrate)
§ 2
cups
of
commercial
sports/electrolyte
replacement
drink
§ ½
to
1
energy
bar
(1
bar
≅
25
to
45
g
carbohydrate)
§ 1
pack
of
energy
gel
(≅
25
g
carbohydrate)
Atkinson
FS,
et
al.
Diabetes
Care.
2009;31(12):2281-­‐2283.

43. Examples
of
Postexercise
Meals
§ Op7on
1
– 1
regular
bagel
– 2
Tablespoons
peanut
buTer
– 8
fl
oz
skim
milk
– 1
medium
banana
§ Meal
provides
562
kcal,
77
g
carbohydrate,
23
g
protein,
and
18
g
fat
§ Op7on
2
– 17-­‐oz
commercial
nutri7on
shake
§ Provides
300
to
420
kcal,
17
to
70
g
carbohydrate,
32
to
42
g
protein,
and
2
to
16
g
fat

44. Progress
Check—Training
1. Carbohydrate
consump7on
during
extended
(greater
than
45
minutes)
exercise
usually
improves
performance.
A. True
B. False
2. Which
of
the
following
carbohydrate
intakes
would
be
most
appropriate
for
a
training
endurance
athlete
(exercising
4-­‐5
hours/day)
who
requires
daily
recovery?
A. 1
g
per
pound
body
weight
per
day
B. 10-­‐12+
g/kg
body
weight
per
day
C. 1500
g/day
D. All
of
the
above
intakes
are
too
low
3. Maximal
glycogen
stores
are
important
for
endurance.
A. True
B. False
44

45. Progress
Check—Training
1. Carbohydrate
consump7on
during
extended
(greater
than
45
minutes)
exercise
usually
improves
performance.
A. True
Correct,
carbohydrate
consump:on
during
long
exercise
periods
can
improve
performance.
B. False
Incorrect,
please
review
slide
Carbohydrates
During
Exercise
Are
Also
Important
to
be;er
understand
the
effects
of
carbohydrate
consump:on
on
performance
during
exercise.
45
û


46. Progress
Check—Training
2. Which
of
the
following
carbohydrate
intakes
would
be
most
appropriate
for
a
training
endurance
athlete
(exercising
4-­‐5
hours/day)
who
requires
daily
recovery?
A. 1
g
per
pound
body
weight
per
day
Incorrect,
please
review
slide
Recommenda:ons
for
Carbohydrate
Intake
During
Recovery
to
be;er
understand
the
various
carbohydrate
intake
recommenda:ons
for
recovery.
B. 10-­‐12+
g/kg
body
weight
per
day
Correct,
an
extreme
exercise
regimen
needs
this
amount
of
carbohydrate
intake
for
daily
recovery.
C. 1500
g/day
Incorrect,
please
review
slide
Recommenda:ons
for
Carbohydrate
Intake
During
Recovery
to
be;er
understand
the
various
carbohydrate
intake
recommenda:ons
for
recovery.
D. All
of
the
above
intakes
are
too
low
Incorrect,
please
review
slide
Recommenda:ons
for
Carbohydrate
Intake
During
Recovery
to
be;er
understand
the
various
carbohydrate
intake
recommenda:ons
for
recovery.
46

û
û
û

47. Progress
Check—Training
3. Maximal
glycogen
stores
are
important
for
endurance.
A. True
Correct,
glycogen
becomes
important
during
high
intensity
and
long
exercise
periods.
B. False
Incorrect,
please
review
slide
Carbohydrates
in
the
Days
Before
Exercise
to
be;er
understand
the
role
of
glycogen
in
exercise.
47

û

48. IV.
Compe==ons

49. Compe==on
§ Compe77ons
some7me
require
different
carbohydrate
intakes
than
prac7ce
– Endurance
may
be
required
for
a
longer
amount
of
7me
– Maximum
glycogen
levels
are
op7mal
for
best
performance
and
require
7me
to
build
(on
the
order
of
days;
not
possible
for
prac7ces)
§ Do
not
try
any
new
foods
in
compe77on
before
you
try
it
at
least
once
at
prac7ce

50. Carbohydrates
as
Energy
at
Different
Times
§ Carbohydrate
consumed
in
the
days
before
event
– Used
to
provide
adequate
glycogen
stores
in
muscle
• Prevent
“hi}ng
the
wall”
§ Carbohydrate
consumed
in
the
hours
before
the
event
– Used
to
preserve
liver
glycogen
stores,
which
can
deplete
aper
approximately
8
to
12
hours
of
fas7ng
§ Carbohydrate
consumed
during
event
– Used
to
maintain
blood
glucose,
especially
when
liver
glycogen
is
depleted
• Carbohydrate
in
the
hours
before
and
during
exercise
helps
to
prevent
“bonking”
United
States
An7-­‐doping
Agency.
Op7mal
dietary
intake
guide.
Available
at:
hTp://www.usada.org/diet/?gclid=COOM-­‐Ky95aYCFQTNKgodzVQL2w.
Accessed
January
31,
2011.
Ensminger
A.
Foods
and
NutriJon
Encyclopedia
2nd
EdiJon
Volume
1.
Boca
Raton,
FL:
CRC
Press
LLC;
1994.
Pages
1202-­‐1203.
Burke
L.
PracJcal
Sports
NutriJon.
Champaign,
IL:
Human
Kine7cs;
2007.
Page
124.
Clark
N.
Sports
NutriJon
Guidebook
4th
EdiJon.
Champaign,
IL:
Human
Kine7cs;
2008.
Page
119.

51. Carbohydrate
Loading
§ Tradi7onal
protocol
– Deple7on
of
glycogen
stores
(~
days
6
to
3
before
event)
• Low-­‐carbohydrate
diet
and
hard
exercise
– Supercompensa7on
of
muscle
glycogen
(~
day
3
before
event
to
day
of
event)
• Very
high-­‐carbohydrate
diet
(8
to
12
g/kg
body
weight/day)
and
tapering
of
exercise
§ Cons
– Deple7on
phase
is
hard
on
the
body
and
difficult
to
tolerate
in
training
• May
lead
to
headaches,
irritability,
and
increased
risk
of
injury

52. Pre-­‐Compe==on
Meal
§ One
of
the
most
variable
aspects
of
the
athlete’s
diet
– Depends
on
individual
tolerance
– Athletes
open
have
certain
beliefs
about
food’s
effect
on
performance
– Ranges
from
no
food
to
the
old
“steak
and
eggs”
breakfast
– Depends
on
the
sport
to
some
degree
§ Func7ons
of
the
pre-­‐event
meal
– Prevent
dehydra7on
– Maintain
adequate
muscle
and
liver
glycogen
levels
– Avoid
excess
hunger
feelings
– Confidence
in
prepara7on
for
the
event

53. Pre-­‐Compe==on
Meal
(con=nued)
§ Medium
amount
of
energy
– 300
to
500
kilocalories,
more
if
there
is
7me
to
digest
before
the
event
§ 2
to
3
hours
before
event
(perhaps
1
hour
with
liquid
meal)
– Inges7on
of
carbohydrate
1
hour
before
exercise
does
not
usually
impair
performance
– Depends
on
individual
tolerance
§ Liquid
meals
are
popular
for
gastrointes7nal
comfort
during
the
event
§ GI
of
pre-­‐event
carbohydrates
– Low
GI
is
recommended
for
endurance
or
high-­‐intensity
events
§ Include
1
to
2
cups
of
fluid
§ Avoid
foods
with
a
high
fat
content
and/or
excess
fiber
Abbrevia7ons:
GI,
glycemic
index.

54. 1.
Clark
N.
Sports
NutriJon
Guidebook.
Champaign,
IL:
Human
Kine7cs;
1989.
Food
Kcal
Carbohydrate,
g
Protein,
g
Fat,
g
Oatmeal,
instant
1
pkt
104
18
4
2
Skim
milk,
½
cup
43
6
4
0
Toast,
2
slices
146
24
4
2
Banana,
1
medium
105
27
0
1
Orange
juice,
6
oz
84
20
1
0
TOTAL
482
95
(80%)
13
(11%)
5
(9%)
Abbrevia=ons:
CHO,
carbohydrate;
pkt,
packet.
Examples
of
Pre-­‐Compe==on
Meals
§ Op7on
1,
liquid
meal
(blend
all
ingredients)1
– 1
cup
of
vanilla
yogurt
– 4
to
6
peach
halves,
canned
or
fresh
– 4
graham
cracker
squares
– Dash
nutmeg,
op7onal
§ Meal
provides
450
kcal,
75%
CHO,
15%
protein,
and
10%
fat
§ Op7on
2

55. Carbohydrates
During
Compe==on
§
Carbohydrate
intake
of
30
to
60
g/hour
during
endurance
exercise
– Consumed
at
10-­‐
to
30-­‐minute
intervals
– 1
cup
of
commercial
sports
drink
has
~14
g
(6%)
– Liquid
form
of
carbohydrate
(ie,
sports
drink)
also
helps
with
hydra7on
§
In
general,
do
not
exceed
– 60
to
90
g/hour
carbohydrate
intake
• 90
g/hour
should
consist
of
carbohydrates
that
use
mul7ple
transporters
– More
than
7%
to
8%
carbohydrates
in
beverages
• Due
to
poten7al
for
gastrointes7nal
distress
– Be
aware
of
sugar
alcohols
and
large
amounts
of
fructose
• A
maTer
of
individual
tolerance
– Find
your
op7mal
range
– Try
first
in
prac7ce,
not
compe77on
Jeukendrup
AE.
NutriJon.
2004;20(7-­‐8):669-­‐677.
Burke
LM,
et
al.
J
Sport
Sci.
2004;22(1):15-­‐30.

56. Progress
Check—Compe==ons
1. Which
of
the
following
nega7ve
effects
is
associated
with
the
deple7on
phase
of
the
carbohydrate
loading
protocol?
A. Kidney
stones
B. Headaches
C. Dehydra7on
D. Hyperglycemia
2. Which
of
the
following
is
a
benefit
of
a
pre-­‐compe77on
meal?
A. Improved
flexibility
B. Reduced
stress
C. Improved
immune
system
D. Improved
hydra7on
E. All
of
the
above
3. When
consuming
carbohydrates
during
endurance
exercise,
it
is
best
not
to
exceed
what
intake
level?
A. 10
to
19
g/hr
B. 20
to
39
g/hr
C. 40
to
59
g/hr
D. 60
to
90
g/hr
56

57. Progress
Check—Compe==ons
1. Which
of
the
following
nega7ve
effects
is
associated
with
the
deple7on
phase
of
the
carbohydrate
loading
protocol?
A. Kidney
stones
Incorrect,
please
review
slide
Carbohydrate
Loading
to
be;er
understand
the
pros
and
cons
of
carbohydrate
loading.
B. Headaches
Correct,
headaches,
irritability,
and
increased
risk
of
injury
may
occur
during
the
deple:on
phase
of
the
carbohydrate
loading
protocol.
C. Dehydra7on
Incorrect,
please
review
slide
Carbohydrate
Loading
to
be;er
understand
the
pros
and
cons
of
carbohydrate
loading.
D. Hyperglycemia
Incorrect,
please
review
slide
Carbohydrate
Loading
to
be;er
understand
the
pros
and
cons
of
carbohydrate
loading.
57
û

û
û

58. Progress
Check—Compe==ons
2. Which
of
the
following
is
a
benefit
of
a
pre-­‐compe77on
meal?
A. Improved
flexibility
Incorrect,
please
review
slide
Pre-­‐Compe::on
Meal
to
be;er
understand
the
benefits
of
a
pre-­‐compe::on
meal.
B. Reduced
stress
Incorrect,
please
review
slide
Pre-­‐Compe::on
Meal
to
be;er
understand
the
benefits
of
a
pre-­‐compe::on
meal.
C. Improved
immune
system
Incorrect,
please
review
slide
Pre-­‐Compe::on
Meal
to
be;er
understand
the
benefits
of
a
pre-­‐compe::on
meal.
D. Improved
hydra7on
Correct,
preven:ng
dehydra:on,
maintaining
adequate
muscle
and
liver
glycogen
levels,
and
avoiding
excess
hunger
feelings
are
all
benefits
of
a
pre-­‐compe::on
meal.
E. All
of
the
above
Incorrect,
please
review
slide
Pre-­‐Compe::on
Meal
to
be;er
understand
the
benefits
of
a
pre-­‐compe::on
meal.
58

û
û
û
û

59. Progress
Check—Compe==ons
3. When
consuming
carbohydrates
during
endurance
exercise,
it
is
best
not
to
exceed
what
intake
level?
A. 10
to
19
g/hr
Incorrect,
please
review
slide
Carbohydrates
During
Compe::on
to
be;er
understand
the
recommended
carbohydrate
intakes
during
exercise.
B. 20
to
39
g/hr
Incorrect,
please
review
slide
Carbohydrates
During
Compe::on
to
be;er
understand
the
recommended
carbohydrate
intakes
during
exercise.
C. 40
to
59
g/hr
Incorrect,
please
review
slide
Carbohydrates
During
Compe::on
to
be;er
understand
the
recommended
carbohydrate
intakes
during
exercise.
D. 60
to
90
g/hr
Correct,
it
is
recommended
to
not
exceed
a
carbohydrate
intake
of
90
g/hr.
59

û
û
û

60. Summary
of
Key
Messages
§ A
high-­‐carbohydrate
diet
helps
to
maximize
glycogen
stores
and
generally
increases
exercise
performance
§ Knowledge
of
the
glycemic
index
of
carbohydrates
can
be
helpful
in
choosing
the
right
carbohydrate
at
the
right
=me
§ Consuming
carbohydrate
during
exercise
also
generally
helps
performance
– Experiment
in
prac7ce
regarding
tolerated
levels
– Liquid
carbohydrates
also
help
with
hydra7on
§ Ea=ng
as
soon
as
possible
afer
exercise
promotes
the
most
rapid
recovery
of
muscle
glycogen
– Combina7on
of
carbohydrate
and
protein
may
facilitate
this
process
§ Frequent,
smaller
meals
can
help
athletes
with
high
energy
and
carbohydrate
requirements
get
in
the
required
amounts
of
nutrients

61. ©
2013
AbboT
Laboratories
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EAS
ACADEMY™
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