I have a mixed opinion. I spent many grueling days/years in a certain military unit and to get there you had to pass selection. I can recall staying in the pushup/flutter kick rotating positions for close to 8 hrs.Hit failure roll over, hit failure roll over and on and on. Yes all day and was so sore I couldn't even raise my arms. When you go days on end without out food/water sometimes and are pushed to the limit day after day one would think it would expose you to rhabdo. I can't recall anyone ever getting it. Only when crossfit come around did I hear and read about it. I have used crossfit and only crossfit for 4 years, straight. Don't anymore, but never had it. But then I am older, where we used to play ball all day in 100 plus temperatures, TV only had 3 channels so who wanted to watch it, no playstation/x box, all we did was run,jump,swim, play from daylight to dark. I think it can happen to anyone but it seems that most people don't have the same GPP that kids or adults used to have. Then I did see one case at FLETC where the kid stayed out all night, drank to much alcohol, chewed tobacco the first time and ended up in the hospital. My opinion was it was his ignorance that caused it although he blamed everyone but himself. I used crossfit programming on 1000 plus candidates a month for almost 3 years and never had one with rhabdo. But then I followed all of my students closely and stopped it short if I had to. Just my 2 cents and you know how that is, everyone has 2 cents.