Nutrition and Athletic Performance – Which dietary supplements and ergogenic aids are effective?
From: Joint Position Statement of the American Dietetic Association and Dieticians of Canada.
- Rodriguez, N.R., Di Marco, N.M., Langley, S., 2009. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc 41, 709–731.
- A review of all identifiable studies with specific exclusions.
- The paper is a systematic review / meta analysis of all relevant trials.
- This means that the data from all similar trials has been grouped to form an overall outcome.
Although dietary supplements and nutritional ergogenic aids, such as nutritional products that enhance performance, are highly prevalent, the fact remains that very few improve performance.
Dietary supplements or ergogenic aids will never substitute for genetic makeup, years of training, and optimum nutrition.
Ergogenic aids that perform as claimed
Creatine has been shown to be effective in repeated short bursts of high-intensity activity in sports that derive energy primarily from the ATP-CP energy system such as sprinting and weight lifting but not for endurance sports such as distance running.
The most common adverse effects of creatine supplementation are weight (fluid) gain, cramping, nausea, and diarrhoea. Although widely debated, creatine is generally considered safe for healthy adults, despite anecdotal reports of dehydration, muscle strains/tears, and kidney damage.
The potential ergogenic effects of caffeine may be more closely related to its role as stimulant and the associated decreased perception of effort.
The use of high-energy drinks containing caffeine can be ergolytic and potentially dangerous when used in excess or in combination with stimulants or alcohol or other unregulated herbals and should be discouraged.
Sports drinks, gels, and bars are commonly used as convenient dietary supplements or ergogenic aids for busy athletes and active people. It is important that qualified nutrition professionals educate consumers about label reading, product composition, and appropriate use of these products (before, during, and after training and competition).
Sodium bicarbonate may be an effective ergogenic aid as a blood buffer (role in acid–base balance and prevention of fatigue), but its use is not without unpleasant adverse effects such as diarrhoea.
Current evidence indicates that protein and amino acid supplements are no more or no less effective than food when energy is adequate for gaining lean body mass.
Ergogenic aids that may perform as claimed but evidence is lacking
The ergogenic aids that have claims as health and performance enhancers include glutamine, A-hydroxyme- thylbutyrate, colostrum, and ribose.
Ergogenic aids that do not perform as claimed
The majority of ergogenic aids currently on the market are in this category. These include amino acids, bee pollen, branched chain amino acids, carnitine, chromium picolinate, cordyceps, coenzyme Q10, conjugated linoleic acid, cytochrome C, dihydroxyacetone, F-oryzanol, ginseng, inosine, medium-chain triglycerides, pyruvate, oxygenated water, and vanadium.
To date none of these products has been shown to enhance performance and many have adverse effects.
Ergogenic aids that are dangerous, banned, or illegal
The ergogenic aids in this category are banned by WADA. Examples are androstenedione, dehydroepiandrosterone, 19-norandrostenedione, 19-norandrostenediol, and other anabolic, androgenic steroids, Tribulus terrestris, ephedra, strychnine, and human growth hormone.
- As per the results above