Moreau and corticosteroids?

Speculation is rife about riders who have abandoned without obvious injury. Moreau comes to mind: French newspaper Le Monde has cast doubts over the former Tour de France stage winner. Confirming that Moreau's blood values did not present any anomalies prior to the Grande Boucle, the paper however alleged that Moreau was sent a letter from the French federation doctor after Paris-Nice this spring. In the letter, the rider was notified of his too low blood cortisol values and asked to stop competing for a while. Along with hematocrit, haemoglobin and reticulocytes, cortisol is part of the French "suivi longitudinal" anti-doping controls, a system similar to the UCI's blood passport, but that has been in place since 1999. Low cortisol in the blood is said to be directly related to the intake of corticoids, which block the natural production of cortisol. According to Le Monde, Moreau is the only French rider who was notified with a "counter-indication to the practice of cycling" in this way.

Yes, prolonged use of glucocorticosteroids will suppress natural cortisol levels, but what is the benefit? These drugs will definitely increase your anxiety and bring anger to the surface more readily, which may help you in a sprint... or not. I wouldn't want to be riding beside an angry or anxious sprinter myself ;-)

Alternatively a rider may seek to use these drugs to reduce muscle mass (they are catabolic, not anabolic steroids). Typically you get thinner skin, and lose both muscle and bone minerals. You may therefore get lighter, but they also cause you to retain water... so the benefit is hard to pin down.