It's been said that anybody can make you tired, or wreck you with a workout. These Iowa football players certainly know that.
Iowa players battling muscle disorder
These guys did a lower body workout including "lower-body workout that involved performing 100 squats in a certain amount of time and pulling a sled 100 yards" and there is a quote from a player saying they also did 100 bench presses. That's a lot of volume at a heavy weight.
The article quotes the school officials as saying the workout wasn't out of the norm, but rhabdomyolysis - basically the catastrophic breakdown of muscle tissue - is rare for a reason; you have to push very hard and very long to get it. I don't mean to cast any aspersions on the trainer at this school, but this seems like a bit much and the players are suffering for it.
Seriously, folks - don't push excessively beyond what you've done before. Ramp it up slowly. Injuries from going too hard too fast - or just plain too hard - are real. My philosophy is to work just hard enough to get the most effect you can from your training, and then stop.