CrossFit Almost Definitely Won't Kill You
LAST DECEMBER, Outside Magazine pointedly raised a question that may have crossed the mind of many a curious exerciser: "Is CrossFit Killing Us?"
Translated from the language of over-the-top, misleading headlines to something normal, the query roughly meant, "Is CrossFit -- an exercise program that emphasizes a blend of high intensity interval training, weighted movements, and a 'push yourself to the limits' mindset -- more dangerous than more traditional modes of exercise?" To answer that, the article employed anecdotes, a single, small study, and an interview with a chiropractor. The response, returned by author Grant Davis -- could best be paraphrased as "Mmmm, potentially."
Just three months earlier, Eric Robertson, an assistant professor of physical therapy at Regis University exposed "CrossFit's Dirty Little Secret." Rhabdomyolysis, a disease in which overexertion prompts the body's muscles to break down rapidly, potentially causing kidney failure, is a common occurrence in CrossFit, he warned, and its everyday practitioners are "largely unaware" of the risk. Except among CrossFitters, rhabdomyolysis isn't a secret at all. In fact, as Robertson himself admitted, CrossFit's unofficial mascot is a clown suffering from the condition. Moreover, CrossFit has been warning its users about rhabdomyolysis since the company was founded back in 2000.
In fact, Robertson's accusations were based entirely on anecdotal evidence. But that didn't matter, because he had the power of foresight.
"My prediction: in a few years, the peer-reviewed scientific literature will be ripe with articles about CrossFit and rhabdomyolysis," he wrote.
WHAT DOES THE evidence really say on CrossFit's safety? A study published in the December 2013 issue of the Journal of Strength and Conditioning Research attempted to ascertain just that. The researchers submitted an online questionnaire to national and international CrossFit forums. To mask the survey's true purpose -- determining CrossFit's injury rates -- the researchers included general questions about training programs, demographics, and supplement use. 132 anonymous responses were collected, with 186 total injuries reported. That may sound like a lot, but the associated injury rate came out to 3.1 incidents for every 1,000 hours of activity. Moreover, no cases of rhabdomyolysis were reported. Mr. Robertson's crystal ball may need to be checked.
"Injury rates with CrossFit training are similar to that reported in the literature for sports such as Olympic weight-lifting, power-lifting and gymnastics and lower than competitive contact sports such as rugby union and rugby league," the researchers reported.
And that rate is positively puny compared to sports like soccer, skiing, and football. Even running may be more dangerous. A 2010 study followed recreational runners for eight weeks as they trained for a 4-mile race. 30.1 injuries were reported for every 1,000 hours of running.
The CrossFit injury study suffers from potentially crippling limitations. For one, it's based on recall, and human memory is notoriously fallible. Since it was posted to online forums and open for anybody to take, sampling bias is also an issue. It's highly unlikely that the study group is totally representative of the CrossFit population.
WHILE THE CURRENT study is by no means exemplary (frankly, it sucks), it is still far preferable to the anecdotal evidence rampant across the Internet. What's truly needed is a longitudinal study that tracks CrossFitters from various demographics and levels of experience over a long period of time -- at least six months.
"This should not be difficult to do, given the vast popularity of the sport," Strength and Conditioning Research's Chris Beardsley wrote.
While we wait for that, both CrossFit's opponents and proponents need to be more reasonable. CrossFit, like any form of exercise, is not without risk. But the benefits far, far outweigh them. CrossFit coaches and trainers need to look out for the health of their athletes, and take care not to push them beyond the bounds of what is safe. That means dialing back intensity, when necessary, and ensuring that participants always utilize proper lifting form. Dying for fitness just doesn't make much sense. Getting fit and living to one's fullest potential; now that does.