Not making excuses for Zirbel, but the guy got popped for a very miniscule amount of DHEA, which has never proven to give any advantage whatsoever physically for performance.
Another useless banned substance...just throw anyting/everything on the list based off myth and fiction....then test everybody for everything.
Abstract
"Dehydroepiandrosterone (DHEA) is secreted by the zona reticularis of the adrenal cortex and is converted into potent sex steroids in peripheral target cells. As oral DHEA administration can lead to dose-dependent increases in circulating androgens, which may reach high supraphysiologic levels in women, it has been included in the list of prohibited substances by the World Anti-Doping Agency (WADA). However, evidence for an ergogenic activity of DHEA is still largely nonexistent. Randomized trials in elderly subjects with an age-dependent decrease in DHEA have provided little or no evidence for enhanced physical performance after long-term administration of DHEA, 50 mg/d, and smaller short-term studies in healthy male athletes using higher doses were completely negative. Thus the widely perceived performance-enhancing activity of DHEA is still more myth than reality. However, because studies in female athletes are still lacking, an ergogenic activity of high-dose DHEA in this population cannot be excluded but is expected to be associated with adverse events like hirsutism, acne, and alopecia."
http://www.ncbi.nlm.nih.gov/pubmed/20122454