Content area
Full Text
Numerous ergogenic aids that claim to enhance sports performance are used by amateur and professional athletes. Approximately 50 percent of the general population have reported taking some form of dietary supplements, while 76 to 100 percent of athletes in some sports are reported to use them. Physicians can evaluate these products by examining four factors (method of action, available research, adverse effects, legality) that will help them counsel patients. Common ergogenic aids include anabolic steroids, which increase muscle mass. These illegal supplements are associated with a number of serious adverse effects, some irreversible. Creatine modestly improves athletic performance and appears to be relatively safe. Dehydroepiandrosterone and androstenedione do not improve athletic performance but apparently have similar adverse effects as testosterone and are also banned by some sports organizations. Caffeine has mild benefits and side effects and is banned above certain levels. Products that combine caffeine with other stimulants (e.g., ephedrine) have been linked to fatal events. Protein and carbohydrate supplementation provides modest benefits with no major adverse effects. (Am Fam Physician 2001;63:913-22.)
Ergogenic aids are substances or devices that enhance energy production, use or recovery and provide athletes with a competitive advantage.
Numerous products claim to bolster strength or endurance in sports. In 1996, approximately 50 percent of the general population reported some supplement use.1 Other surveys have shown that 76 percent of college athletes, and 100 percent of body builders take supplements.2 Americans spent $11.8 billion on supplements in 1997, with a predicted growth rate of 10 to 14 percent in 2000 (Table 1).3
New products with ergogenic claims appear on the market almost daily. Most are classified as supplements, which means the contents of the product and the claims on the label have not been evaluated by the U.S. Food and Drug Administration and may not have any scientific basis. The following questions will help the physician and patient determine whether a product is worth taking:
1. What is the physiologic basis or theory for this product's action?
2. Are there any scientific studies published in peer-reviewed journals that support or refute the claims that the product makes?
3. Are there any side effects, especially any potentially serious adverse effects?
4. Is the product legal?4
This article reviews some of the...