Athletic Performance and Protein Intake

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Athletic Performance and Protein Intake
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Protein Basics

• Proteins are molecules have many enzymatic and
  structural functions related to the growth,
  maintenance and repair.
• The goal of dietary protein intake is to
  contribute the amino acids necessary to
  assimilate proteins for skeletal structures and
  hormones, function as cell membrane receptors and
  maintain fluid balance.

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Protein needs are estimated by measuring nitrogen
balance... Nitrogen balance in (protein
intake) out (sweat, urine and feces)
Protein Turnover 200g-400g daily Protein
Degradation catabolism Protein Synthesis
anabolism These two mechanisms employ different
pathways. Both pathways are always on. Nitrogen
balance reflects the net protein degradation or
synthesis at the whole body level.
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Protein Synthesis

• For athletes in training their goal is to
  maintain or increase lean body mass (FFM)
• An increase in muscle size and thus mass is
  caused by an increase in protein synthesis.
• Increased protein synthesis is reflected by an
  positive nitrogen balance... Anabolic
  environment.
• Muscle mass maintenance (endurance athletes) is
  sustained by discouraging protein degradation.
• Protein degradation is reflected in a negative
  nitrogen balance... Catabolic environment.

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Dietary Protein Requirements

• The RDA for protein in normal sedentary
  individuals is 0.8g/kgBW (1kg2.2lbs)
• For a 130lbs person(130/2.2)0.8 47g
• For a 180lbs person(180/2.2)0.8 65g
• Athletes have increased protein needs compared to
  sedentary people but there is some debate about
  how much protein athletes really need...

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Protein and Athletes

• General belief
• Endurance performance CHO intake
• Strength/Power performance protein intake
• But this is not true. All athletes have an
  increased need over sedentary people for dietary
  protein.
• Goal of endurance athletes provide amino acids
  for energy , maintain FFM
• Goal of resistance athletes gain/maintain FFM

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Protein Needs in Athletes

• Endurance Athletes
• Protein oxidation occurs as an energy source
• After prolonged or high intensity exercise a
  negative net protein balance is seen
• Training seems to have a protein sparing effect,
  protein oxidation during exercise decreases with
  training
• Recommendations, agreed upon by most researchers
• 1.2-1.8g/kgBW
• For 130lbs person (1.5g/kgBW) 88g
• For 180lbs person (1.5g/kgBW) 122g

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Meeting dietary protein needs in Athletes...

• Endurance
• Ex Tour de France. Athletes have difficulty
  maintaining energy balance but are in nitrogen
  balance. Research has shown a linear relationship
  between energy intake and protein intake. When
  they consumed 12 protein of 6500kcal, easily met
  requirements.
• When energy intake matches output in endurance
  exercise athletes dont need to supplement with
  extra protein.

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Protein Needs in Athletes

• Resistance Training/Strength Athletes numerous
  research studies but no clarity about how much
  extra protein a strength athlete needs.
• The goal of the resistance trained athlete is to
  increase FFM (must be in positive protein balance
  after exercise, promote muscle synthesis)
• The general consensus is that a general increase
  in dietary protein intake will promote muscle
  growth

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Strength Athletes

• Research has shown
• Tarnopolsky et al. recommended that athletes
  involved in high intensity sports resistance
  training consume 1.76g/kg/BW of protein to
  maintain a positive nitrogen balance.
• 130lb person 104g
• 180lb person 144g
• They also showed that 1.0g/kgBW maintained
  nitrogen balance while 2.77g/kgBW attained a
  positive balance that was twice that of the lower
  group.

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• Also evidence that body-builders require only
  0.82g/kgBW to maintain balance...
• Surprisingly one study found that athletes
  couldnt maintain nitrogen balance with an intake
  of 2.0g/kgBW.
• Conflicting results in dietary protein
• recommendations are due to problems with
• methods used and intensity of the training.

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• Lemon et al. adds to the body of literature
  suggesting that strength and power athletes need
  between 1.5-2.0g/kgBW
• Evidence has shown
• protein needs in strength athletes increase with
  changes in intensity and volume to their training
• This need for extra protein is negated after 12
  days of training. (temporary in response to a
  training stimulus)
• With further increases in training loads, protein
  requirements are also increasing to promote
  synthesis.

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Meeting dietary protein needs in Athletes...

• If athletes consume 15 of their calories as
  protein are they getting enough to promote an
  increase in FFM?
• Lets do the math for a male involved in a
  moderate intensity resistance training program
  (160lbs72.7kg)
• PROTEIN CONSUMED
• TDEE 3000kcal
• 15 of 3000kcal 450kcal/4kcal/gPRO 112g PRO
• 112/72.7 1.45 g/kg BW/day

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Meeting dietary protein needs in Athletes...

• What about 20?
• 3000kcal 20 569kcal/4kcal/gPRO140g
• PRO 1.9 g/kg/day
• Is simply increasing dietary protein intake
  sufficient to maintain or increase FFM?

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• After exercise the environment of the body is
  catabolic (favors protein breakdown).
• Feeding promotes protein synthesis
• Increases amino acid pool
• Elevated plasma insulin reduces protein breakdown
• What should I eat?
• A mixed meal is recommended with at least 1g of
  CHO/kg BW and 0.5g PRO/kg BW after an intense
  training session.
• 180lbs (81.8kg) 82g CHO and 41g PRO

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Protein Intake and Protein Synthesis

• Rasmussen et al. (2000)
• After a bout of resistance exercise subjects were
  fed 6g of a.a. plus 35g sucrose
• Plasma a.a. increased 3-fold, insulin increased
  10-fold
• Muscle protein synthesis was increased 3.5 fold.
  There was no increase in breakdown.
• Control condition saw a net protein breakdown.

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• The effect of timing...
• If feeding is delayed by 24hours net protein
  balance is negative and no muscle hypertrophy
  occurs.
• Order of CHO and protein in post-exercise
  meal...should CHO precede protein?
• Shifting environment to the fed state by
  ingesting CHO first may limit the oxidation of
  absorbed amino acids
• Trade-off is that the stimulatory effect of amino
  acids on protein synthesis is delayed with this
  tactic.
• CHO/PRO consumption during exercise...
• Insulin levels are very low at the end of
  exercise, consuming carbohydrate would maintain
  them and decrease protein oxidation.
• If athlete is using a muscle group and then moves
  on to another muscle group, significant time
  would pass until the post-exercise meal.

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Muscle growth, fat loss

• In order to promote muscle growth we need an
  anabolic environment and to be in both energy
  surplus and positive nitrogen balance.
• To minimize fat gain during an anabolic state of
  training, choose lean proteins (chicken/fish) vs.
  fatty ones (beef/lamb)
• Fat loss requires an energy deficit, but thats a
  catabolic state.
• To minimize muscle loss during an energy deficit,
  increasing protein intake gt20 would be suitable
  to maintain nitrogen balance.

Successfully increasing FFM is a delicate balance
between energy intake and expenditure that must
be carefully planned and closely monitored.
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Protein Sources

• 9 essential amino acids that must be obtained in
  the diet
• Protein Quality
• Complete protein
• have all amino acids, including the essential
  ones
• Ex meat, fish and dairy products
• Incomplete protein
• Have some of the amino acids, not all
• Ex nuts, grains, legumes
• (vegetarian athletes may need to supplement with
  synthesized pure amino acids)

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Protein Sources

• Beef (3oz) 28g
• Pork (30z) 28g
• Milk (1 cup) 8g
• Egg (1) 6g
• PB (1tbsp) 8g
• Apple (1) 2g

• Choose lean protein sources. Chicken has
  subcutaneous fat that can be peeled away but beef
  cuts have fat marbled throughout the skeletal
  muscle.

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Whey
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• Whey is derived from
• cows milk. As the
• schematic on the right
• shows, whole milk is 13
• stuff.
• That stuff is 27 protein
• The protein is 20 whey

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What is whey anyway?

• According to the Whey Protein Institute, whey is
  a pure, natural, high quality protein...it is a
  rich source of the essential amino acids needed
  on a daily basis by the body.
• In its purest form, as whey protein isolate, it
  contains little to no fat, lactose or
  cholesterol whey provides a number of benefits
  in areas including sports nutrition, weight
  management, immune support, bone health, and
  general wellness.
• A less biased description is cows milk protein

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Why could whey be better than other protein
sources?

• Whey protein also has a relatively high
  proportion of branched
• chain amino acids (BCAA)
• BCAA amino acids (leucine, isoleucine, valine)
  are not
• synthesized and therefore must come from the diet
• Leucine is an initiator of protein synthesis
• Whey protein is rapidly absorbed data are mixed
  on whether
• this affects protein synthesis
• Whey protein is a dairy protein and recent
  research suggests
• that calcium and other minerals in dairy may aid
  in weight loss

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Athletes have expensive urine...