What Does It All Mean?!

Thursday, July 27th 2006
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Doping in professional cycling. Everyone let out a *gasp*.

Okay, so we don’t know anything officially yet. It could all be a big mistake. But, how exactly does testosterone help professional athletes? And just how plausible are Landis’ potential excuses?

Landis told SI.com that elevated levels of testosterone are a common problem among cyclists and that he is retaining the services of Spanish doctor Luis Hernandez to help prove his innocence. “In hundreds of cases, no one’s ever lost one,” Landis told the Web site.

Landis also told SI.com that he has been taking an oral dose of thyroid hormone to help a thyroid condition he’s been treating. He also suggested cortisone shots he’s been given for his hip might have contributed to the test result.

Testosterone and other androgens promote muscle growth and hematopoietic stem cell maturation (we all remember when Lance was accused of giving himself EPO, a drug specifically used to raise one’s red blood cell count and thus increase your oxygen delivering capacity).

As for Landis’ claims, they sound semi-plausible. I have no idea how one identifies testosterone in the lab, but increased levels of thyroid hormone could raise one’s testosterone levels. From what I understand increased levels of thyroid hormone increase the overall level of testosterone in your body, but also increases the levels of SHBG. Since most of your testosterone is bound to that, the level of free testosterone isn’t greatly affected by increases in thyroid hormone. If they’re measuring levels of free testosterone, I’m not sure how strong Landis’ argument is, but if the lab is deducing the levels from SHBG, then Landis might have somewhat of an argument.