I was asked to address the subject of Rhabdomyolysis with respect to CrossFit since it has been hammered on in a very vague, frightening, and uninformative way in the news and social media as of late. This isn’t going to be some story about a guy I knew once who got rhabdo because he did 5000 pushups or something subjective like that. I’m going to try to educate you and to present this as objectively as possible. Then I’ll give you some tips on how to mitigate your chances of getting it. I’ll let the info speak for itself and you can make up your own mind because you are, after all, an adult and should be able to do that. Although the odds of someone getting Rhabdo are low, it is a serious condition and should be treated as such. If you haven’t read “The Truth About Rhabdo “in the CrossFit Journal then read it first and then come back to this. That article was written in January of 2010 and there are earlier articles in the Journal going back as far as 2005 (carry the two….yeah 8 years ago).
Rhabdomyolysis (Rhabdo) is the breakdown of striated muscle cells that causes the release of potentially toxic contents, specifically myoglobin and creatine kinase (CK), into the blood stream. CK is a compact enzyme found in both the cytosol and mitochondria of tissue where energy demands are high (…..muscles). Under normal circumstances the renal system (kidneys) can handle levels of 20-200 CK U/L no problem. You are sitting reading this with CK levels that fall somewhere in there. Levels above 5000 CK are indicative of serious muscle disturbance and anything above 10,000 CK is indicative of Rhabdo. (Pearcy, 2013) . Metabolic muscle disturbance is thought to result in release of cellular components through a cascade of events, which begin with depletion of ATP and result in the leakage of extracellular calcium ions into intracellular space. Intracellular proteolytic enzyme activity can increase and promote muscle protein degradation and augmented cell permeability, which allows some cell contents to leak into the circulation. (Pearcy, 2013) CK levels of up 100,000 are not uncommon in trauma and 20,000 or below are unlikely to be associated with renal impairment if given treatment. In 1995 US hospitals reported 26,000 cases of Rhabdo. 85% of trauma patients will experience some form of Rhabdo. There are numerous causes of rhabdo, physical and nonphysical e.g. crushing, drug or alcohol use, heat stroke, ischemia, low phosphate levels, seizures, severe exertion, and trauma. Symptoms can include severe muscle soreness, discolored urine (coke pee), swelling, muscle stiffness, and weakness about the joint. (David C. Dugdale III, 2011) For the purposes of this article we will only address the incidences of Rhabdo that are not secondary to trauma (I don’t mean getting traumatized by a WOD!), intoxications or adverse drug reactions. What we are talking about is commonly referred to as Exertional Rhabdo.
In 2011 there were 435 incidences of exertional rhabdo reported in the US Armed Forces, 207 of which resulted in hospitalization. There are roughly 1.4 million active service members. This is a crude incident rate of 29.9 per 100,000 p-yrs, or .000299% of the military population. (Center, March 2012 Vol 19 #3) . Most of these cases were reported from installations that support basic combat/recruit training where a considerable amount of physical training happens. 72% of the cases were reported to have significant association with heat stress and dehydration, occurring between May and September. These statistics would indicate that hydration levels are a major contributing factor to rhabdo. Outside of heat stress two more common themes of diagnosed rhabdo patients are untrained people, short term and long term, and muscle movements involving high volume or heavy loading of eccentric contraction. You can translate that last as dehydrated, out of shape (or short term training break) athletes doing far too many eccentrically loaded movements i.e. pull ups, jumping pull ups, GHD sit ups. Read that sentence again and evaluate each athlete differently when they walk in the door. As a Coach that is your job! As an athlete it’s your responsibility to assess yourself and communicate with your coach. It’s a two way street.
There appears to be no established link between habitual exercise or acute high-intensity eccentric exercise and raised incidence of kidney dysfunction or muscle disorder in normal healthy individuals, even in the presence of CK levels >20.000 U/L−1. The contribution of additional factors such as genetic disposition, environmental conditions, or disease may increase the risk of exertional rhabdomyolysis resulting in acute renal failure. Individuals who regularly participate in high-volume, intense exercise, tend to have significantly raised base levels of CK compared to sedentary and moderately exercising individuals. Raised levels of serum CK were also found in regularly exercising pre-menopausal women compared to similar sedentary individuals; this suggests that CK flux into the serum is a natural and normal reaction to regular exercise. (Baird, 2012)
This entire argument has gone astray because of the improper use of the term “CAUSE”. As CrossFit grows and continues to occupy a larger portion fitness industry there will continue to be more skeptics and opponents. This discussion will surface again down the road and it will be “new” even though it has been beaten to death. Articles stating CrossFit causes Rhabdo or anything of the like are misleading at best and generally offer no fact based data to support the subjective opinion of the given author. Rhabdo is a real thing and it can be life threatening if untreated, but CrossFit does not cause rhabdo. If that were the case then 7000+ affiliates worldwide would be shutting down because their members would be dead or in the hospital. Can an athlete, fit or unfit, get Rhabdo during a CrossFit WOD? Yes. Will CrossFit be the only variable involved? No. The reality of the scenario is that there are far more factors that will come into play other than your exercise routine. You can also get rhabdo from a car accident, from basic military training, from training in the heat, and running long distances. So if someone is going to argue that because there is an extremely low chance of someone getting rhabdo that they should not do CrossFit, then it would be reasonable to argue that you should not drive your car, exert yourself in direct sunlight, run, or join the military simply because risk is present. Does all of that sound a bit extreme and misinformed? Yeah, so does “CrossFit will give you Rhabdo!” Here’s what will give you Rhabdo: being ignorant and foolish. As CrossFitters it’s our duty to continue to be hyper vigilant about rhabdo and educate people on the risks involved. We must continue to push the envelope of human performance while treading lightly to avoid recklessness. CrossFit has long argued that the movements we do are inherently safe post 1RM loads when done correctly, and that the benefits far outweigh the risk of injury. There is no 100% safe training program that yields any kind of positive adaption to overall fitness. It simply doesn’t exist.
In CrossFit the rhabdo discussion is so far from a secret it’s comical to label it as such. It has never been a secret, beaten around the bush, disguised, misled, or any other way you want to phrase it. If you have attended the Level 1 Certificate Course then you know this is required reading for the course in addition to being discussed and how to mitigate it. Yes, it is addressed every weekend in roughly a dozen cities around the world and people are educated on how to avoid inducing it.
So here are some tips for beginners and experienced athletes
1) Stay hydrated
2) Scale reps and load if you are just starting or if you are coming off any sort of hiatus in your training
3) Be very careful with high rep eccentric movements i.e. GHD sit ups, pull ups, jumping pull ups, pushups (arguing that doing 150 pull ups vice 50 is better for you is a hard sell, more is not better)
4) Talk to your coach, only always.
5) Take responsibility for your own health, there is no medal at the end of the WOD (unless you find yourself center stage in Carson, CA) so don’t be stupid with your WOD
6) Lastly, if you have dark urine or severe delayed onset muscle soreness (DOMS) go to the hospital and get it checked.
Rhabdo isn’t new and is in no way exclusive to CrossFit, quite the contrary actually. The first recorded incidences of rhabdo are believed to be described in bible during the exodus of the Jews from Egypt. Some of the first medically recorded cases of Rhabdo were during the bombing of London in WWII. (Huerta-Alardín, 2005) I’m not saying because you can get rhabdo from a multitude of scenarios that it’s ok. GETTING RHABDO IS NOT OK!! I’m saying there are risks involved with everything. Educate yourself and make smart decisions. There are risks in CrossFit, just like anything else worth pursuing. Those risks are very low and can be almost completely mitigated. Those risks are far outnumbered by the positive aspects of a program whose efficacy is unmatched.
Keep training hard and hit your weaknesses,