Performance-enhancing supplements.

Abstract

Supplements that are marketed as ergogenic aids have achieved widespread use in the United States. In image-conscious society, these agents are not only being consumed by athletes, but also by those looking for a quick fix to enhance their appearance. Many assume that the performance claims made by the manufacturers are based on actual data, and that these agents must be safe because they are sold to the general public. Unfortunately, in most cases these assumptions are false. Creatine has become very popular, particularly among college and high school athletes. Studies within the last 5 years have shown that creatine does seem to have certain ergogenic benefits in a laboratory setting. It is not currently known whether these benefits actually can be transferred to the playing field. Although creatine has not consistently been shown to cause any major side effects, there is some question regarding creatine's effect on the kidneys, particularly with long-term use. Also, the safety of supplementation in children and adolescents has not been examined at all; its use in this population should be discouraged until there are more data. Androstenedione is an agent that has received a large amount of popular press in the last year, and this has led to an surge in its usage. It is believed to exert its ergogenic effects through conversion to testosterone. But what limited data are available suggest that at the recommended dosage, it does not cause any measurable change in testosterone levels, or provide any ergogenic benefit in inexperienced weight lifters. Also, it has yet to be determined whether androstenedione causes any of the side effects often attributed to use of the illegal anabolic steroids. Its mechanism of action suggests it has the potential to cause many of these negative effects. Studies are just beginning to appear in the literature, and certainly more data need to be gathered before androstenedione supplementation can be recommended for use as an ergogenic aid.