Hormones As Dope
Tuesday, August 8, 2006
After repeated testing of a sample of Tour de France winner Floyd Landis's urine revealed apparent doping with testosterone, one detail seemed to seal the case: The sample suggesting there were artificially high levels of the hormone in his body was collected immediately after his stunning come-from-behind performance on the 17th stage of the 20-part race.
Clearly, the speculation was he'd juiced up right before the big ride.
A lot isn't known yet about what Landis took and when he took it. But a lot is understood about testosterone, the naturally occurring hormone that makes males men. And none of it suggests that it would have helped Landis much if he had binged on a synthetic form of the man-juice right before his comeback ride.
Testosterone's abilities to enhance performance when taken at high doses accrue gradually, so athletes who abuse it usually do so over an extended period, experts say. This stuff is not Popeye's spinach.
The conventional wisdom is that "you need a while for it to work," says Linn Goldberg, an internist at the Oregon Health and Science University in Portland and a spokesman for the Endocrine Society.
"I'm not familiar with [testosterone] being used effectively the day of an event, because it takes time to have an impact," says Gary I. Wad-ler, an internist at the New York University School of Medicine and a consultant to the World Anti-Doping Agency.
When taken over time, testosterone can confer a number of athletic advantages: increased muscle strength and size, improved bone strength and a higher count of red blood cells, which transport oxygen to demanding tissues. Taking the hormone regularly can also reduce muscle soreness after workouts, cutting recovery time, Goldberg says.
He and other experts note, however, that artificially inflated levels of testosterone have serious side effects and risks, including infertility, dangerous enlargement of the heart, prostate enlargement, balding, and acne. By boosting red-cell count, it may also trigger strokes. The hormone can produce psychological effects such as aggressiveness that, while adverse in most contexts, could aid competitive athletes under pressure to perform, says Wadler. But it's not known whether these mental changes happen fast enough to help an athlete immediately before competition.
"There's not really been a good study to show an acute response to a single dose," says endocrinologist Richard J. Auchus of the University of Texas Southwestern Medical Center at Dallas. "You can see manic responses in some people in just a few days, but it's not uniform from person to person."
Let's Go to the Glands
Testosterone is made primarily in the testes, which is why it's the trademark male sex hormone. (Women make smaller amounts in their ovaries and adrenal glands, and usually have about 5 percent as much testosterone as men do.)
The testes release numerous pulses of testosterone every day, and men's blood concentrations generally rise during the night and decline during the day, Auchus says. The hormone's level in urine reflects average blood levels during the period the urine was made. In men, levels change little from day to day or week to week, although they decline with age.
As the body makes testosterone, it also generates a biologically inactive byproduct called epitestosterone. Most people have about equal amounts of those two hormones.