Overexertion most likely caused the muscle condition that sent 13 University of Iowa football players to the hospital  last week. Sports medicine experts say that such severe cases are rare among intercollegiate athletes and are easily prevented by close monitoring of their training and exercise. And some advocates for college athletes say that the incident suggests a need to more closely monitor and regulate what coaches ask of athletes.
Exertional rhabdomyolysis, the condition with which the Iowa football players were diagnosed, is simply described as the muscle soreness one feels after exercise. Priscilla M. Clarkson, distinguished professor of kinesiology at the University of Massachusetts at Amherst and past president of the American College of Sports Medicine, said most people who complain of this soreness after a workout at the gym actually have a mild case of the condition. She explained that the normal process of building muscle involves the micro-tearing and repairing of muscle tissue.
In more serious cases, Clarkson said, a protein called myoglobin leaks out of the muscle and into the bloodstream. Too much myoglobin in the blood — more than the kidney can safely cleanse — can lead to renal failure. The primary warning signs are severe, lasting muscle pain and brown urine, she said.
Certain exercises are more apt to cause rhabdomyolysis, said Clarkson, pinpointing specific kinds of muscle contractions, such as those involved in doing squats or pull-ups. She also noted that the condition is exacerbated by three main causes: overexertion, dehydration or heat stress. Clarkson defined overexertion as “any exercise done in great excess of what is normally done.” For example, if one normally does 25 squats at a time, then doing 100 at a time would be considered excessive.
Clarkson said coaches can easily prevent the condition by “sensibly increasing the exercise gradually,” ensuring players are properly hydrated and keeping them from working out in hot environments.
Overexertion is the likely cause of the recent cases with the Iowa football players, Clarkson said. University of Iowa officials are still investigating  what caused these cases, but they have confirmed that the players were involved in grueling off-season workouts prior to their hospitalization.
Still, Clarkson said, cases severe enough to require hospitalization are rare. The last known major cases among intercollegiate athletes were those of seven University of South Carolina swimmers  in 2007.
“There are really isolated cases of this,” Clarkson said. “Renal failure is very rare. I mean, for anyone to die of this is really, really rare. I hear about a case of this from time to time. Other than what the NCAA says, I’m not sure there’s anything else that can be done. The coaches [at Iowa] probably did too much with these athletes, and they probably know that now and will never do it again.”
The most recent NCAA Sports Medicine Handbook , cited by Clarkson, does briefly discuss rhabdomyolysis. It states that there is “no valid reason” for the “intentional dehydration” of athletes, noting that “the use of laxatives, emetics and diuretics should be prohibited.” Similarly, it notes that “the use of excessive food and fluid restriction, self-induced vomiting, vapor-impermeable suits (e.g., rubber or rubberized nylon), hot rooms, hot boxes and steam rooms should be prohibited.” Finally, the handbook warns that the risk of severe exertional rhabdomyolysis is 200 times greater in athletes with sickle cell trait and that extra caution should be paid to these athletes during workouts to ensure they do not overexert themselves.
Some sports medicine experts caution that coaches can push their players too far during training. Rupert Galvez, a Denver-based doctor, wrote in a 2008 Clinical Journal of Sports Medicine article  that the seven South Carolina swimmers who had the condition likely "pushed themselves to a further physical tolerance and higher pain levels, possibly driven by self-motivation or peer/coach pressure, because there were no set limits on the maximum number of push-ups they were required to perform." He argued that coaches needed be made "aware of the need for sufficient rest periods after strenuous exercise during preseason conditioning."
In light of the recent cases of rhabdomyolysis in Iowa, NCAA officials are referring their member institutions to the best practices available in the association’s handbook, noting that it has had policies regarding this condition since the mid-1970s. They defend the association’s regulations limiting practice and workout time.
“NCAA legislation provides practice opportunities during which institutions can conduct workouts,” wrote David Klossner, NCAA health and safety director, via e-mail. “Determination of the content of those workouts are best handled by the local athletics staff to meet the individual needs of student-athletes. [An institution is] responsible for establishing a safe environment for its student-athletes to participate in its intercollegiate athletics program.”
Officials from the Big Ten Conference, of which Iowa is a member, noted that they do not limit practice and training any further than the maximums put in place by the NCAA. They had no further comment on rhabdomyolysis.
In spite of the recent cases and the perception that college athletes are being increasingly overworked, Clarkson does not believe there is an epidemic of the rare muscle condition in intercollegiate sports.
“There are always some people who overdo it,” Clarkson said. “That doesn’t mean it’s happening in every sport. I don’t think this is all over the country either. We’d know more about it if it was. I don’t think coaches are pushing athletes too much, on the whole, because if they did they wouldn’t be able to play them at all. Coaches are always walking a fine line to push kids to get trained. These coaches [at Iowa] obviously made a mistake and got these kids doing too much. But this condition is just very rare.”
Advocates for athletes, however, are more critical of what the recent cases suggest for student safety.
"It's a big red flag for 13 student-athletes to be hospitalized at the same time," said Ramogi Huma, president and founder of the National College Players Association. "Every program out there needs to re-evaluate their training regimen. I don't know if the [Iowa] coach was trying something new in the workout routine or what, but for players to be hospitalized because they were overworked says something."
Huma, who was a linebacker on the football team at the University of California at Los Angeles, said he had not heard of rhabdomyolysis prior to the Iowa cases last week. He said strength and conditioning coaches need to improve their communication with sports medicine officials to ensure that conditions like this do not become commonplace. Huma added that he believes the recent cases of rhabdomyolysis correlate with the recent string of heat-related deaths  of football players in recent years.
"The common thread in all of these cases is that the human body can only be pushed for so long," Huma said. "It doesn't seem like that line has been well-defined."