Athletes Who Have Used It: Gilbert Arenas, Terrell Owens, Michael Phelps

What It's Supposed To Do: Hyperbaric oxygen chambers are designed to help more oxygen get into your bloodstream. The thought is that that additional oxygen can then be used to heal soft-tissue injuries more quickly than usual.

Athletes have actually been using hyperbaric oxygen chambers for years now. They've become more popular in recent years with more and more athletes buying them for their homes. But this Sports Illustrated article from all the way back in 1994 proves that athletes have been turning to them for more than two decades. And they swear by them. The problem: Athletes do need to be monitored while using them, because putting too much oxygen into the blood can cause things like brain seizures. But when used properly, they seem to be helpful.