The Big Idea: The steroid DHEA (dehydroepiandrosterone) has been touted as a wonder pill that pumps up muscle mass, increases endurance, and amplifies one's sense of overall well-being. Sounds like something the FDA should be keeping a closer eye on, right? Turns out, Congress excluded DHEA from the list of supplements it banned in April 2005. Today, you can purchase the pills at your local health food store.

The Reality: If you're under 40, as I am, your body already produces ample DHEA. I tried a doctor-suggested five-milligram-a-day dose for a month and didn't feel a thing. After age 40, though, natural DHEA nose-dives, which is why the supplement has grown popular among mature triathletes. But according to Owen Anderson, Ph.D., editor of Running Research News, older athletes can reap the same benefits (greater strength, enhanced well-being) and avoid nasty side effects ("backne," anyone?) by simply improving their training: "Reach for higher-quality training, not the pill bottle."