Stiverne was hospitalized for two nights at University Medical Center after dropping a unanimous decision to Wilder in a fight in which he was passive and didn't throw early enough punches. He was severely dehydrated and was diagnosed with rhabdomyolysis. Former UFC heavyweight champion Junior dos Santos suffered from rhabdomyolysis following his loss to Cain Velasquez at UFC 155 in 2012 in Las Vegas. Rhabdomyolysis is a condition in which the muscle fibers die and are released into the blood stream. One of the causes is extreme physical exertion. Stiverne was severely dehydrated even in the days leading up to his bout with Wilder, and after the fight, his urine was a brown color. "There were [doping control] agents there and I had to do my post-fight test, and I noticed that my urine was very dark," Stiverne said. "I thought it was blood. I called my manager [Camille Estephan] and [trainer Don] House over and told them. But when I got to the hospital, I found out it wasn't blood. It was from the muscle damage."
So he over exerted himself in the fight. Wilder wore him out. If he had Rhabdo BEFORE the fight it would have shown up in the pre fight medical
he was over exerted leading up to the fight in training it seems and having a tough 12 round fight makes it worse
Rhabdo is something that is noticable in any **** test(the muscle literally breaks down so much that it seeps into the urine. It makes your urine go a very dark colour). If he had it before the fight, it would have showed up in any medical, and unless he has complete idiots training him, he would have been taking it easy in his last week before a fight