In UBs case it doesn't make sense for him to be on the juice. He took up atheletics at a relatively late age as a teenager and even at that stage was putting out times that would put him in an Olympic final. He is quite unusual for a sprinter in that he's obviously very quick, but also very tall, 6'5. Most big guys that tall, don't have a quick stride pattern and so can't cycle their legs quick enough. Most big guys in rugby are in the forwards, because they are big and strong, but also because they can't run quick. In the 100m UB used 41 strides and Tyson Gay used 44 strides. That's what makes UB so quick. Unless someone can match his number of strides then he will remain unbeatable. There is still a chance he's on the gear and I'm beyond shock now when people get busted in Athletics, but in his case I doubt it.