CrossFit's Dirty Little Secret

Everyone has an uncle they'd rather you not meet.

Please allow me to introduce you to Uncle Rhabdo, CrossFit's unofficial and disturbing mascot. Uncle Rhabdo is a cartoon commonly referenced in CrossFit literature and representative of a troubling trend among CrossFitters.

He's a clown. Literally.

The "Uncle Rhabdo" cartoon depicts an exhausted, yet well-muscled clown, connected to a dialysis machine standing next to some workout equipment. Concernedly, his kidney has fallen out and lies on the floor underneath him, along with some portion of his bowel. He's left a pool of blood on the floor below him, but it's not clear if this is from the disembowelment, the kidney's arterial supply, or the collection of fasciotomies he appears to have endured. Uncle Rhabdo, of course, has rhabdomyolysis.

Rhabdomyolysis, apart from being a subtly pleasant and melodic sounding word, is an uncool, serious and potentially fatal condition resulting from the catastrophic breakdown of muscle cells. We'll get more into the specifics in just a bit, but first let's begin with a story.

A Tale of Rhabdomyolysis

One day, a very fit, young, physical therapist colleague of mine went to CrossFit. She had been many times before. On this warm Texas evening, she performed a partner workout, where each would trade off performing sets of 10 for each exercise. The workout consisted of pushups. Lots of them. Copious amounts of overhead press were also included.

She performed hundreds of repetitions of each. She was a champ!

"I didn't want to not match my partner. Normally I may have rested a little, but the partner workout kept me going."

Both of these activities heavily involve the triceps muscles and so she wasn't surprised to have her beautiful, sculpted arms feel like poorly set bowls of JELL-O on the way home from CrossFit. Perhaps it was the heat. Maybe it was the sheer number of exercises she did. Her muscles were in crisis. She iced and hydrated when she got home, like a good little exerciser, but the damage was already done.

As physical therapists, we're finely tuned detection machines looking for normal versus abnormal response to exercise and activity. "Is this supposed to hurt?" is a question we respond to hundreds of times in a week. Sometimes the answer to this question is yes and we encourage the individual to press on, and other times it's a signal to initiate some rest and recovery. This signal detection is one of the things that's deeply embedded into physical therapists. We can't help it. And so when my friend awoke the next morning, her abnormal response alarms were blaring. She couldn't bend her elbows! She couldn't even reach her mouth to brush her teeth.

Still entrenched in the CrossFit culture of deplete, endure, repeat, she quieted the alarms and stoically pressed on to go to work. It didn't take long to realize she not only couldn't bend her arms, they also had no strength. She wasn't able to treat her patients. By that evening, her slender arms had continued to swell into plump hotdogs of ache and regret, and she was starting to come to the realization that the morning's danger alarms were legitimate.

Unbelievably, it took another 24 hours for her professional sense to break through the grip of the CrossFit culture, and seek medical attention. She was diagnosed with acute rhabdomyolysis, and ended up in the hospital for over a week. While in the emergency department they tested her creatinine kinase (CPK) levels. Normal is about 100. Her CPK levels were more than 45,000, a number that indicated damage to the kidneys.

While in the hospital, she called to cancel her CrossFit membership. As is standard when something is cancelled, the CrossFit coach asked the reason for her decision. She replied, "I'm in the hospital." The instructor quickly asked, "Is it rhabdo?"

And here we have arrived at CrossFit's dirty little secret. The coach was unusually familiar with what is normally a very rarely seen disorder. It's so rare that one study reported the overall annual incidence of rhabdomyolysis to be 0.06 percent. That represents single digits of cases out of hundreds of thousands of patients. How, I wondered, is it possible that the layperson exercise instructor is on a first-name basis with a serious, yet rare medical condition? Is this a thing with CrossFit? It turns out it is.

Rhabdomyolysis: As Told By CrossFit?

A quick search of the Interwebs reveals copious amounts of information about rhabdo purveyed by none other than CrossFit trainers . Scouring the scientific literature in mainstream medical journals, however, reveals a only a few peer-reviewed papers. The science confirms that exertional rhabdomyolysis, as this form is sometimes referred to, is uncommon and normally reserved for the elite military trainee, ultra-endurance monsters, and for victims of the occasional psychotic football coach. Rhabdomyolysis isn't a common condition, yet it's so commonly encountered in CrossFit that they have a cartoon about it , nonchalantly casting humor on something that should never happen.

So what is rhabdomyolysis exactly? Under extreme conditions your muscles cells explode. They die. They leach protein out into the blood stream, including one form called myoglobin. Ever stalwart, your kidneys take up the job of clearing these dangerous proteins from the blood. Why? It's just what they do. Unfortunately, myoglobin proteins aren't designed to be in the blood in the first place and they can easily overload the kidney. This can produce injury or death to all or part of the kidney in a short amount of time, and is potentially lethal. Locally, the muscles are left damaged and dying. Swelling ensues and weakness occurs as pressure builds around the remaining muscle cells. Your body's systems that normally can assist with this local muscle damage are now offline trying to help you not die. If you get to this stage, you're in serious trouble.

In some cases, acute compartment syndrome ensues, which is an emergency condition that can result in loss of a limb unless your connective tissue is slashed open to release the swelling , a procedure called a fasciotomy . None of this is something that people should be handling in such a cavalier manner.

So what gives? As early as 2005, the New York Times documented rhabdomyolysis associated with the culture of CrossFit in a piece entitled, "Getting Fit, Even If It Kills You ." The article included this gem of a quote:

"Yet six months later Mr. Anderson, a former Army Ranger, was back in the gym, performing the very exercises that nearly killed him. "I see pushing my body to the point where the muscles destroy themselves as a huge benefit of CrossFit," he said."

What does CrossFit's founder, Greg Glassman think of this?

"It can kill you," he said. "I've always been completely honest about that."

Fast forward to 2013 and this culture has changed little, perhaps even accelerated. As Jason Kessler pointed out in "Why I Quit CrossFit ," the elitist, push yourself to the limit culture of the discipline has increased in light of commercial interests taking hold. Regarding culture, Jason points out:

"If you ask a CrossFit coach, the injuries were all my fault. In a culture that drives you to go as hard and fast as possible, it's difficult not to get caught up in the hype. You're supposed to push yourself to the limit, but when you hit the limit and pay the price, you're the idiot who went too far."

In another psychotic example of how the overwhelming culture of CrossFit can diminish professional common sense, one gynecologist was quoted dishing this nonsense:

"Ladies, in my professional opinion, it is okay to pee during double unders."

No, peeing during a workout is not alright. Ever.

To underline the point, MoveForwardPT.com , the official consumer information website of the American Physical Therapy Association (APTA), hosted an online radio show specifically responding to CrossFit's irresponsible glorification of stress-induced urinary incontinence.

The Impact of Rhabdomyolysis

Sometimes rhabdomyolysis gets better with treatment. Sometimes it lingers. Sometimes your kidneys are never the same again. One message board commenter remarked :

"I seem to "flare" after any resistance training. I came into this by over training -- I was in phenomenal shape. I have gained weight. I get swollen and puffy. I feel as though the quality of my muscle tissue decreases on a daily basis -- more so than the lack of weight training -- seems to be disintegration."

My friend experienced a similar, though thankfully less severe long term effect. It's been several months and her triceps strength is not back to normal. Her sculpted arms are gone, replaced by semi-swollen jiggly tissue. Once a muscle tears, damaged, fatty scar tissue replaces the injured muscle tissue. The result is a permanently damaged muscle, and a decreased ability to strength train. The irony of pushups causing flabby arms underscores the age-old mantra: There really is too much of a good thing.

CrossFitters, largely unaware of the rhabdo risk, will continue to charge ahead, pressured and happily coerced into exercising to depletion and exhaustion. My prediction: in a few years, the peer-reviewed scientific literature will be ripe with articles about CrossFit and rhabdomyolysis. Health providers will be there to scoop up the pieces, but who is there to protect those people unknowingly at risk?

Exercise is just about the best thing you can do for your body, but in the case of CrossFit, we're left to ponder the question, is this workout worth the risk? Can the culture adapt to one that embraces safe training principles? Do coaches truly have the ability to detect what a proper training load is for their athletes? Only time will tell, but the future of CrossFit may depend on it.

Eric Robertson is assistant professor of physical therapy at Regis University in Denver, Colorado. He operates and writes for the website PTThinkTank.com . This piece first appeared on Medium .

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