CrossFit vs. Science
For almost 15 years now, CrossFit has taken plenty of criticism. Some of it valid and some of it not. One of the biggest negative talking points is an alleged high risk of injury due to a "perfect storm" of exercise choice, training volume, intensity, fatigue, and technique.
There have actually been numerous scientific studies to investigate those allegations, as well as other effects of CrossFit-style training. CrossFit has taken increasingly larger steps – everything from social media counter-arguments to full legal proceedings – to address some of those claims.
While some of the studies show CrossFit in a positive light, some certainly show it negatively. But the question has been raised: Are those studies truly valid and unbiased?
Over the last few years, there have been dozens of studies published in various journals, each examining different aspects of CrossFit training – everything from the effect of peri-workout nutrition during CrossFit workouts, to the role of music during a session, to the prevalence of injuries from "high intensity CrossFit-style training."
Of those studies, several in particular have earned the ire of CrossFit HQ and have warranted, in their eyes, further scrutiny. The most recent target was a study titled "CrossFit-based high-intensity power training improves maximal aerobic fitness and body composition," published in The Journal of Strength and Conditioning Research by the National Sports and Conditioning Association (NSCA).
While this study actually showed measurable, beneficial improvements in fat loss and VO2 max from CrossFit-style training, it also reported that several participants withdrew before completing the 10-week program, supposedly suffering from what the study vaguely called "overuse or injury."
This unfortunate addendum was too much for CrossFit to tolerate once word got back to CrossFit HQ that, in fact, those participants may have actually withdrawn for non-injury-related issues and the injury statistic (9 out of 54, or 16% of the sample population) was either creatively-interpreted or simply invented by the study administrators.
It turns out that the study's participants were members of an Ohio CrossFit box and, CrossFit community being what it is, word of mouth spread quickly about the injury allegations, with the volunteers soon telling friends and fellow box-goers their side of things.
Does the general public know the full story behind what happened with the study participants? Of course not. Well, not yet at least.
A lawsuit (appropriately titled "CrossFit Inc vs. the NSCA") has been filed in the state of California, so the full facts will certainly come out eventually. The CrossFit box which provided the participants is also suing the NSCA and the study administrators in a separate lawsuit.
CrossFit claims that the NSCA fabricated the statistic, at least partly as an attack on the CrossFit business model. Both the NSCA and CrossFit offer trainer certifications and are technically "business competitors."
In other words, CrossFit claims that the NSCA hoped to discredit them in the eyes of the public and among fitness professionals by giving scientific credence to the frequently-circulated allegation that CrossFit training is dangerous.
While it's true that both organizations are popular among fitness professionals seeking certification, the study would end up being some strange kind of modified compliment sandwich – "CrossFit-style training does help you burn fat, and it does get you into better shape, but you might get hurt... pretty much just like any hard and effective training program."
If that's how you decide to attack a competitor, you're either fiendishly clever, supremely confident, or maybe it just wasn't an attack.
The Devor Study, as it has come to be unofficially known, warned of the "risk of overuse injury" in part of one paragraph of its 17-page report, and the topic of injuries was tangential to the original purpose of the study.
The study does take some less-than-scientific liberties when stating that the benefits of CrossFit-style training "may not be worth the risk of injury and lost training time," but closes that paragraph/section with the catch-all reminder:
"Further work in this area is needed to explore how to best realize improvements to health without increasing risk above background levels associated with participation in any non-high intensity based fitness regimen."
In other words, "Whatever it is, we should still be on the lookout for safer ways to train effectively." Seems reasonable enough. While it's clear that any training program comes with potential risk relative to the intensity of exercise, it's inexcusable if the 16% statistic was fudged in any way, regardless of reason.
Further, one of the most overlooked talking points is that there have been some studies which determined that CrossFit-style training has a just-about-average rate of injury when compared to more traditional bodybuilding-style, powerlifting, or Olympic lifting-focused plans. On paper, CrossFit actually seems to pose no excessive risk when compared to almost any other training someone could do in the gym.
CrossFit has developed a reflexive habit to counter-attack when it's the subject of studies that may show them in a poor light. Specifically, CrossFit points to at least four studies all published in the NSCA-operated The Journal of Strength and Conditioning Research, each seeming to investigate various aspects of "High Intensity/Short Rest" or HI/SR training (essentially, CrossFit-type workouts done for time) and examining the effects of fatigue on exercise technique and joint health – two cornerstones of the general "CrossFit is dangerous" argument.
The results of each of these studies seem to advise against HI/SR training and, as a result, add to the anti-CrossFit movement. However, the NSCA does lump various training methods/techniques such as Tabata intervals, CrossFit, and what they call "Tough Mudder race preparation" training all into this same category, which can complicate the issue.
It could certainly be seen as "convenient" that the NSCA is also on record as stating:
"Specialty certification is not needed if the professional has an independently accredited certification that provides appropriate coverage of the subject matter."
So from the NSCA's point of view, you don't need to learn how to specifically coach CrossFit's methods if you've got a well-rounded general certification. It's a debatable point, for sure, but it's a potentially persuasive one if you're already holding a certification from the people making that claim.
If CrossFit HQ was sent into a furor over the NSCA's possibly-inaccurate and certainly negative comments about injury rate, one has to wonder why CrossFit founder Greg Glassman and other high-ranking CrossFit staff would make possibly-inaccurate and certainly negative comments regarding the American College of Sports Medicine's (ACSM) hydration guidelines from 1996.
Note: The ACSM is also a trainer-certifying agency, just like the NSCA and CrossFit, and is technically "business competition" for both organizations.
In November of last year, the same month the Devor Study was published, CrossFit posted a link on their Facebook page to a 2012 Outside Magazine article that discussed potential dangers for athletes who overhydrate, and CrossFit HQ added the statement:
"Twelve athletes have since died from drinking too much during exercise. Coca-Cola and PepsiCo (via Gatorade) continue to sponsor the ACSM's research."
Side Note: CrossFit denied Outside Magazine a press pass to cover the 2014 CrossFit Games, stating that they questioned Outside's intentions. This was, according to Outside, payback for reporting about supposed CrossFit injury rates and CrossFit's new competition, the National Pro Grid League. In short, Outside crossed CrossFit... and you just don't do that unless you want to be "bullied" by founder Greg Glassman and his keyboard warriors.
Three months later, Glassman posted a thread on the CrossFit message board titled "Exercise Associated Hyponatremic Encephalopathy, Gatorade and the ACSM."
In it, Glassman declared that the ACSM's 1996 hydration guidelines (which were revised in 2007) have lead to "the deaths of at least a dozen people, and serious injury to thousands of others [...] The cause of these deaths was pure and simple over-drinking promoted by Gatorade and the ACSM." This claim has been repeated on CrossFit social media and numerous CrossFit-related blogs/journals.
There have been approximately 12 deaths in the US between 1989 and 2002 attributed to exercise-associated hyponatremia or exercise-associated hyponatremic encephalopathy (basically, dangerously-low sodium levels and swelling of the brain as a result of drinking excessive amounts of fluid).
The majority of fatalities have been military personnel in training with the rest being post-competition marathon runners, although the most recent studies indicate that events like ultra-marathons or endurance events lasting longer than six hours pose the greatest risk.
However, any specific connection between Gatorade or the ACSM and the deaths or non-fatal cases of hyponatremia seems to be a stretch since it's obviously difficult to determine exactly why an individual (let alone a deceased individual) would decide to drink a certain amount of a certain beverage. It's also not clear, by any means, that Gatorade was specifically the beverage of choice for any of those affected.
CrossFit alleges that the ACSM allowed itself to be influenced by Gatorade, one of its corporate sponsors, as the ACSM suggested that athletes "consume the maximum amount that can be tolerated." The ACSM addressed similar previous criticism with a 2007 article published in the British Journal of Sports Medicine titled "Manufactured arguments: turning consensus into controversy does not advance science."
There, the ACSM agreed that overhydration could potentially lead to hyponatremia, but pointed out that their actual hydration guidelines in 1996 stated: "During exercise, athletes should start drinking early and at regular intervals in an attempt to consume fluids at a rate sufficient to replace all the water lost through sweating (i.e., body weight loss), or consume the maximal amount that can be tolerated."
Drinking enough to counteract bodyweight loss via sweat would seem, on the surface, to be a reasonable suggestion to avoid a loss of performance. Neglecting that half of the advice while focusing solely on the latter portion could certainly lead to health and performance issues.
The ACSM's 2007 revisions tried to clarify the situation with instructions to customize a pre-, during-, and post-exercise hydration plan according to several variables (gender, age, nutrition, activity, etc.).
While they did already address this exact issue in their 2007 paper, the ACSM hasn't yet responded directly to the recent CrossFit claims, but it will be interesting to see if they echo CrossFit's method of response to the NSCA – via social media and lawsuits – or if they disregard it, possibly seeing it as a trumped up non-issue, bordering on trolling, undeserving of further attention.
In any case, the result of the ongoing CrossFit-NSCA legal battle will also be interesting and could easily set a trend for future studies into exercise performance. It's rare enough for scientific studies to have relevant carryover into the real world. Having to worry about possible ulterior motives behind a study, press release, or public announcement shouldn't have to be a concern.
As with most fitness situations, the best bet with new information is to take everything with a grain of salt (no hydration pun intended), do some basic research, and allow for some trial and error tempered with common sense.