Concern for InjuryA more pressing concern is the potential for injury. CrossFit WODs sometimes use Olympic lifts, like the snatch, for high repetitions when lifters are in a state of exhaustion. That worries almost everyone I interviewed.
"The problem has to do with fatigue and going to failure," says Stuart McGill, Ph.D., a professor of spine biomechanics at the University of Waterloo, Ontario. "Some exercises are conducive to this and others are not." McGill puts Olympic lifts in the "not" category.
"Repeating movements where form is compromised with fatigue really does not fit the philosophy of Olympic lifting to reduce injury risk and enhance performance."Then there's the issue of coaching. "You can learn the mechanics of an Olympic lift in 2 days, but you can't develop enough of a proficiency to teach others," Krahn says. "The guy who's teaching you a complex movement may have very little knowledge about it."
Rhabdomyolysis is another health concern that's become associated with CrossFit over the years. "Rhabdo" can occur when muscles are worked so hard that the fibers break down, releasing the protein myoglobin into the bloodstream. In extreme cases, it can lead to kidney damage or even kidney failure. It's commonly seen in people with crush injuries, such as those from auto accidents.
Former U.S. Navy information systems technician Makimba Mimms was awarded $300,000 in damages from his local gym, the CrossFit affiliate training company, and his trainer for injuries he sustained during a CrossFit workout in 2005. Those injuries included rhabdomyolysis.
Rather than refute the association with potentially fatal injury—or at least try to change the subject—CrossFit has used it as proof of its intensity. The WOD that nearly killed Mimms was renamed "Makimba" and recategorized as a children's workout.
The derision ignores not just the seriousness of Mimms's injuries but also the fact that no one is immune to rhabdo, including elite athletes. In January 2011, a local paper reported that 13 football players at the University of Iowa were hospitalized with rhabdo after a workout that included 100 squats with 50 percent of their 1-rep max. It wasn't a CrossFit workout, but it was in the same ballpark: a technically complex exercise performed for high repetitions under conditions of extreme fatigue.
http://health.yahoo.net/articles/fitness/inside-cult-crossfit?page=2