Most accounts of adverse events associated with ergogenic supplement use have been reported as individual cases or small case series. Relatively little prospective data are available regarding the safety of most emerging ergogenic supplements. Studies of self-reported use show that 40 to 60 percent of young athletes have taken nutritional supplements to improve performance. A significant number of adolescents have also experimented with anabolic-androgenic steroid use. 6 Most of the information that young athletes receive regarding the effectiveness of these products comes from the lay press, anecdotal evidence or word of mouth.
Athletes are often reluctant to discuss ergogenic supplement use with their physicians.
The medical community is to blame for any mistrust between athletes and physicians in this arena. During the 1970s and 1980s, a credibility gap was established when physicians repeatedly told athletes that anabolic steroids did not improve strength or add muscle mass. While some supplements may be of some benefit to some individuals in some situations, there is little doubt that most products fail to meet purported claims of efficacy. Ahrendt 1 provides a useful table that summarizes the ergogenic claims of current supplements and the evidence for or against their effectiveness. The list of supplements banned by the International Olympic Committee is extensive.