Cause you dont take Drostanolone unless its a last minute thing. Chances are he was very close to fight time. And it being his biggest fight ever and the fact that it was his last fight he didnt want to mess it up. Maybe he even got injured late in to the training camp and he knew weight must be made.
Thats my guess anyway. Without more info on the subject its hard to say exactly. But weight cutting is weight cutting and i know many of your panties will get in bunches over it but i really still could care less.
Its cheating according to the commission.
That doesnt have to mean its cheating according to me.
If you dont see that then i dont know what to tell you.
Actually Drostanolone is very performance-enhancing.
It's not nearly as anabolic as say testosteron, but it's even more androgenic, wich means you get all the other effects even more, such as agression, endurance and all the properties that makes men into men other than the actual muscle-building capability.
The more androgenic the steroid, the more suited it would be for a sport where musclebuilding isn't the primary goal.
Ben Johnson was stripped of his gold medal in the 100 meter sprint at the 1988 Summer Olympics when he tested positive for stanozolol after winning the final, stanozolol is extremely similar to Drostanolone. Both are based on DHT.
It does indeed also help with the weight-cutting but it's far from it's only effect.
Fluoxymesterone would probably be one of the even better choices if pure agression, abilty to push the pace and just really being an animal in cage is the goal. But Drostanolone isn't a bad choice.
Now this is striclty speculation on my part but I think maybe Bonnar knew that the only way he would have a chance against Silva was to try and do what Sonnen did the first fight and overwhelm Anderson before he can settle in to his rythm. He figured he was even bigger than Sonnen and that in combination with pushing Silva like Sonnen did + his blackbelt in BJJ to not get subbed, might have him win that fight.
Didn't work out very well but it would explain why he would take Drostanolone, since for pure weightcutting purposes there are way better diuretics out there.
I'm not trying to be a smart-ass but I really have to explain that Drostanolone isn't just a diuretic.