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Transcript
Maximizing Recovery
Lecture 18 Part II
Most of us will never get to this point... but we do
get tired from training on consecutive days.
Are there supplements that can help athletes
recover faster and allow them to train hard
consistently without risking the development of
chronic fatigue/overtraining syndrome/illness?
Intense Exercise Training
Depleted intramuscular energy stores,
accumulation of waste products, impaired
circulation, activation of proteases by calcium,
and release of lysosomal proteases that lead
to intracellular degradation.
Muscle soreness, weakness,
pain, signs of inflammation,
lack of energy
Intense Exercise Training
Muscle Glycogen
Depletion
Muscle Fiber
Damage
ACTH
Translocation of
GLUT4 to muscle cell
membrane, enzymes
for glycogen storage
are upregulated.
Cortisol
Suppresses
inflammation and
accelerates
breakdown of
muscle protein to
amino acids
Cortisol
• Adrenocorticotropic hormone (ACTH) is
released by the posterior pituitary gland in
response to fiber damage.
• ACTH causes release of cortisol to help
suppress inflammation and mobilize amino acids
from muscle protein degradation
• Cortisol in relation to recovery:
– Assists in fuel provision (amino acids via
gluconeogenesis)
– May delay recuperation after intense exercise
Intense Exercise Training
Muscle Glycogen
Depletion
Muscle Fiber
Damage
ACTH
Carbohydrate + Protein
Stimulates an ANABOLIC
environment
Cortisol
Suppresses
inflammation and
triggers
breakdown of
muscle to aa
Protein Supplements
• Meat and Vegetable
• Other “common” proteins that are found at
the GNC in power form:
– Whey Protein
– Casein
– Egg Protein
– Soy Protein
– Glutamine the “Magic Protein”
Whey Protein
• Derivative of milk production
• Amino acid profile closely related to aa
required by humans
– Contains a surplus of essential amino acids
• Also has immune-enhancing properties
– Contains high levels of cysteine, an amino
acid substrate for glutathione (an antioxidant
necessary for lymphocyte proliferation)
Casein
• Similar to whey-also a derivative of milk
production.
• Whey vs. casein:
– Casein induces a longer elevation of plasma
amino acids (likely due to slower gastric
emptying)
– Casein has been shown to inhibit whole-body
protein breakdown
– Whey protein increases protein synthesis
more than casein.
Egg Protein
• Kool-aid and Eggs in a blender...yummy.
• Egg protein substitutes:
– Egg protein powders are higher in sodium
(>300mg per serving)
– A good source of essential amino acids.
Cost: $31.25, 2lbs
Soy Protein
• Contains high amounts of glutamine and
arginine
– Glutamine: deficiencies have been related to intense
strenuous exercise, increased infection, suppressed
immunity and critical illness.
– Arginine: has a vital role in stimulating the release of
growth hormone and insulin growth factor-1 (IGF-1)
• Soy is low in the sulfur-containing amino acids,
methionine and cysteine
– Important in glutathione synthesis
Soy Cont’d
• Studies:
– Soy vs. beef/meat: no differences in nitrogen
balance or net protein use
– Soy vs. whey (1998 at Ohio State, 20 healthy
males involved in a heavy exercise program)
• Subjects fed soy had an increase in plasma
anti-oxidants while the whey group did not.
• Soy contains isoflavones which may oppose
free-radical production.
Protein Supplements
• Meat and Vegetable
• Other “common” proteins that are found at
the GNC:
– Whey Protein
– Casein
– Egg Protein
– Soy Protein
– Glutamine the “Magic Protein”
Glutamine
• Naturally occurring nonessential amino acid.
– Synthesized in the muscle.
• Most abundant free amino acid in muscle and in
plasma
– Serves as a metabolic fuel for lymphocytes,
macrophages and for cells lining the intestine.
– Means of nitrogen transport between tissues
• A metabolic link between muscle and the
immune system.
– Immune cell function is connected to the synthesis
and release of glutamine in the muscle.
Strenuous exercise affects immune
system:
- depressed lymphocyte count, impaired
function of natural killer and B cells...etc
(parts of the immune system that recognize
and destroy foreign invader cells)
O
R
D
E
R
I
N
F
O
R
M
A
T
I
O
N
Glutamine Hypothesis:
Exercise has immunosuppressive effects
(marathon running is associated with more upper respiratory infections in
the week or two following the event)
Glutamine is associated with immune function
Plasma glutamine levels are lowered by
intense endurance exercise.
Hypothesis: additional glutamine will enhance the
resistance to infection in athletes.
Evidence?
Glutamine manufactures claim:
• More rapid water absorption
• Improved fluid retention
• Nutritional support for immune function
and prevention of infection
• Stimulation of protein synthesis and
muscle tissue growth
• Stimulation of muscle glycogen resynthesis
• Reduction of muscle soreness and
improved muscle tissue repair
• Studies testing glutamine hypothesis:
ONE STUDY HAS SHOWN A POSITIVE EFFECT...
– Castell et al. looked at the effect of post-marathon
glutamine supplementation on the incidence of
respiratory infection in the week following the race.
• Marathon participants were given 5g of glutamine or placebo
within 2 hours of finishing the race and were monitored over the
next 7 days.
• Results: 20% of the athletes that consumed glutamine reported
an infection vs. 50% of the athletes that consumed a placebo
drink reported infection (p<0.001).
There is also a study done in rats that showed
glutamine helped preserve lymphocyte proliferation
after exercise (treadmill running).
• Let’s think about this from a basic science
standpoint.
– Does exercise decrease free glutamine
concentrations?
• Prolonged moderate exercise (50-70% VO2max) is
associated with 10-30% decrease in plasma
glutamine concentration.
• Intense exercise >90% VO2Max can also
decrease glutamine.
(May be the window of increased susceptibility for
infection in the hours following exercise.)
– Are free glutamine levels associated with
immune system function?
• Preventing a fall in plasma glutamine concentrations
(post-exercise dose at 0, 30, 60 and 90 minutes) did
not prevent a fall in lymphocyte activity.
• Maintaining plasma glutamine by consuming a drink
before during and after cycling did not prevent a fall
in immune factors like leukocyte trafficking,
neutrophil function, lymphocyte proliferation and
natural killer cell activity.
Can glutamine supplementation increase
plasma glutamine and affect factors that are
enhance the immune system?
• Evidence thus far does not support the
glutamine hypothesis. Maintaining plasma
glutamine levels has not been CLEARLY
shown to enhance immune system
function although anecdotally it is
prescribed widely by strength and
conditioning coaches to aid in recovery.
Intense Exercise Training
Muscle Glycogen
Depletion
Muscle Fiber
Damage
ACTH
Carbohydrate + Protein
Stimulates an ANABOLIC
environment
Cortisol
Suppresses
inflammation and
triggers
breakdown of
muscle to aa
PERFORMANCE=?
Side-note
• Glutamate is not glutamine... Many
manufacturers add glutamate to
supplements because it’s cheaper than
glutamine. Make sure you read the label.