Nutritional ergogenic aids

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Nutritional ergogenic aids
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Key factors to consider with any ergogenic aid
research

• Subject variables
• Measurement variables
• Study design
• Protocol supplementation
• Statistical procedure

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Definition

• Nutritional substances or phenomena that
  improves an athletes performance

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Potential ergogenic aids

• Creatine supplementation
• Bicarbonate loading
• Branched-chain amino acid supplementation

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Found naturally in coffee beans, tea leaves,
cocoa beans and therefore chocolate, Coca Cola
etc.
Endurance performance Significantly longer
exercise capacity after caffeine (Costill et
al., 1978). - Increased FFA metabolism, reduced
RER. - Reduced RPE
Intense aerobic exercise Significantly
reduced 1500m swim times (MacIntosh et al.,
1995).
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High intensity exercise No proven effect on
peak power or mean power of exercise lasting
upto 5 mins.
Strength 2 studies have found a small increase
with caffeine Lanigan et al. (1993) 3.8
Kalmar Cafarelli (1999) 3.5
Strength Endurance Time to fatigue at 50 MVC
increased by 25 (Kalmar Cafarelli, 1999)
with caffeine.
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Caffeine is a banned substance in competitive
sports with a threshold urinary concentration of
12mg/mL.
However less than 3 of caffeine appears in the
urine, and 500mg of caffeine is unlikely to
exceed this threshold.
With habitual caffeine users there may be a
reduced ergogenic effect.
Side-effects, particularly with large doses in
non-habituated caffeine individuals, can
includes headaches, insomnia, restlessness etc.
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Special Nutritional Adverse Event Monitoring
System

• Run by US -Food and Drug Administration
• http//vm.cfsan.fda.gov/dms/aems.html

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Sodium Bicarbonate
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Proposed ergogenic benefit

• Increased release of lactate and H from muscle
• Delayed onset of fatigue
• Improved high intensity exercise performance

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Muscle lactate transporter
Bonen et al. 1997
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Physiological effects of bicarbonate ingestion

• Increased plasma bicarbonate levels
• Results in increased increased buffering capacity
  of plasma

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Costill et al. (1984)
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• Blood pH is elevated at rest and during intense
  exercise

Costill et al. (1984)
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• Resting muscle pH is unchanged
• For the same work rate and duration, reduction in
  contracting muscle pH is attenuated

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Costill et al. (1984)
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• Elevated efflux of lactate from contracting
  muscle

Spriet et al. (1986)
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Is there an ergogenic effect?

• Greater than 40 studies published
• Study results are conflicting
• Meta-analysis (Matson and Tran 1993)
• Analysis used randomised, double blind studies
  which investigated performance and were published
  in English
• 29 studies with 285 subjects met criteria

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• Sodium bicarbonate has a positive effect on
  exercise performance (27 ? 20) increase in time
  to fatigue

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Factors to consider

• Benefits are most often observed with exercise
  duration between 1-7 min
• Dose needs to be 0.3 g/kg body weight
• Dose taken over 1-2 hr in 5 parts with 1-2 litres
  of water
• Side effects - GI discomfort - diarrhea, cramps,
  bloating

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NaHCO3 and 1 hr performance ride
McNaughton et al. (1999)