The only guy I'mk not suspicious about is Donaire. Hopkins could be taking EPO, which increases the amount of oxygen carried by the blood and so massively boosts stamina. All the cyclists take it. It's undetectable one hour after injecting. He could also be taking |HGH which improves recovery time and helps with injuries. Also basically undetectable. There are other things as well. Even if he is taking stuff, and he probably is, he's still an amzing fighter and a freak of nature.