Skip to content

Experts explain the tests athletes undergo to determine testosterone levels and other indications of performance-enhancing substances.

For Tour de France winner Floyd Landis, the results of his doping test mean the difference between glory and disgrace. For sports doctors, the issue may be a coldly scientific one: Can a night of drinking dramatically alter results of a steroid test? (And how accurate are these tests anyway?)

Meanwhile, fans watching from the sidelines have been left a bit confused by all the talk of testosterone ratios and what might affect them. WebMD went in search of some of the answers.

Question: What is testosterone?

Answer: Testosterone is the "male" hormone, accounting for strength and endurance. It occurs naturally in men and in smaller amounts in women. For every molecule of testosterone produced by the body, another molecule of a substance called epitestosterone, which does not enhance performance, is made.

In a normal male body, the ratio of testosterone to epitestosterone, the T/E ratio, is about 1:1. But variation can occur in individuals, and the World Anti-Doping Code has deemed 4:1 as the threshold for a positive test.

Question: What is synthetic testosterone?

Answer: This anabolic steroid is a form of testosterone usually produced from soy or yams in factories, not the human body. It can be introduced into the body by injection, with patches, or other means.

Question: What happens to the body when it is introduced?

Answer: Gary Wadler, MD, chairman of the Prohibited List and Methods Committee of the World Anti-Doping Agency (WADA), says this would be a deliberate attempt to increase muscle strength and mass, shorten recovery time from vigorous exercise, and keep muscle tissue from breaking down (catabolism) when pushed to the extreme.

Steroid Abuse

Question: How common is "doping" with anabolic steroids?

Answer: Of every 100,000 samples from athletes analyzed at 24 labs around the world for the International Olympic Committee, 1.6% come up positive -- 65% of those for anabolic steroids.

Question: Does synthetic testosterone kick right in and provide an immediate boost?

Answer: This has doctors puzzled in the Landis case. Apparently, the contender did poorly on one leg of the race, went out to drown his sorrows, and then had a miraculous recovery the next day to win. Wadler says this is not typical of how synthetic testosterone works. "Most effects surface after a few weeks," Hellman says, "not a few hours."

Healthy Recipe Finder

Browse our collection of healthy, delicious recipes, from WebMD and Eating Well magazine.

Top searches: Chicken, Chocolate, Salad, Desserts, Soup

Heart Rate Calculator

Ensure you're exercising hard enough to get a good workout, but not strain your heart.

While you are exercising, you should count between...