Nutrition for Athletes - Commonwealth Games Federation

athletes’ medical informationSupplements and dopingAthletes who are liable for drug testing undernational or international programs should beespecially cautious about supplement use.Some supplements are prepared inunhygienic conditions and contain toxins thatmay cause gastrointestinal problems. Othersdo not contain some or all of the ingredients— especially the expensive ones — that arelisted on the label. Contamination of dietarysupplements with substances that may causean athlete to fail a doping test is widespread— some surveys have suggested that as manyas one in four supplements may result in apositive test. These prohibited compounds havenot been declared on the label, so there is noway for the athlete to know that they are present.Purchases through the Internet pose an evengreater risk, and extreme caution should betaken. A sports nutrition expert should beconsulted before taking any supplements.At present, there can be no guarantee of thepurity of any commercial supplement. The onlyway to be sure is to avoid supplementsaltogether, but many athletes are unwilling toaccept this advice. The sensible athlete willwant to see very good reasons for using asupplement and a very low risk of an adversetest before deciding to use it.There is no evidence that prohormones suchas Androstenedione and Norandrostenedioneare effective in enhancing muscle mass orstrength. These prohormones are promoted foruse by athletes and are readily available inshops and via the Internet, but they will resultin negative health consequences as well aspositive drug tests.Many herbal supplements are claimed toincrease testosterone levels and hence havean anabolic action. These include: TribulisTerrestris; Chrysin; Indole-3-Carbinol; SawPalmetto; Gamma-oryzanol; Yohimbine; Smilax;Mummio. All of these claims are based onstudies in test tubes and none has been shownto work in humans. Athletes are cautionedagainst the use of these supplements.Athletes must be aware of the strictliability principle that makes themresponsible for everything they eatand drink.Ignorance is not an acceptableexcuse for a positive doping result.Check all supplements with amedical officer or qualified sportsnutrition specialist. If there is anydoubt at all, don’t take it.29