I have lot of friends that do CrossFit. They are always posting their WOD (Workout of the Day) pictures on Instagram, tweeting about kettlebells, posting pictures of the abs. We all get it, you do CrossFit. I even did CrossFit. (Granite, I was forced because my college lacrosse coach was a CrossFit trainer). But there is one thing all those CrossFit people are not posting on their social media. It's "CrossFit's dirty little secret" of rhabdomyolysis (Robertson 2013).
Rhabdomyolysis is a risk of doing too much CrossFit. It is a muscle injury in which your muscle cells essentially burst (Robertson 2013). The membrane of the myocyte becomes injured and altered energy production takes place which results in an increase of intracellular calcium concentration which then initiates a destructive process (Zimmerman and Shen 2013). Calcium is an essential component of muscle cells. It is required for contraction of muscle. Normally, calcium is released by the sarcoplasmic reticulum when the "gate keeper" of the calcium receive a voltage signal to open. Calcium then comes rushing out of the sarcoplasmic reticulum and binds to troponin on actin, one of the protein filaments required for muscle contraction. The binding of calcium to troponin allows the other required protein filament, myosin, to interact with actin, eventually leading to contraction of the muscle. When the muscle cell membrane is damaged, calcium from outside the muscle cell comes pouring into the cytoplasm of the muscle cell. Adding this increase of calcium to the calcium that is released from the sarcoplasmic reticulum triggers multiple destructive processes(Zimmerman and Shen 2013). All these processes eventually lead to cell lysis or the cell bursting. When the cell burst, all the cellular contents are taken up into the bloodstream. One of the most dangerous "escapes" of this cell burst is the protein of muscle cells called myoglobin (Zimmerman and Shen 2013). Your body does have a way to filter out all these muscle "escapes". The kidney is called upon to clear myoglobin out of the blood (Robertson 2013). Unfortunately, myoglobin was put in muscles for a specific reason. It has a very high oxygen affinity and does not participate in "sharing" oxygen well like hemoglobin. It allows your muscles to be very good at keeping oxygen for themselves to use in contraction. Since myoglobin belongs in the muscle and not in the blood, the kidneys can become very overwhelmed. When this happen, myoglobin is toxic to the kidney. Kidney damage and renal failure is huge concern of rhabdomyolysis (Zimmerman and Shen 2013).
So how does "overdosing" on CrossFit lead to rhabdomyolysis? CrossFit leads to muscle exertion. Repetitive muscle exertion can damage the muscle cells beyond the point of repair. Rhabdomyolysis is seen often in elite military trainees and is becoming prevalent in CrossFit participants (Robertson 2013). Unfortunately, people are unaware that damage has occured until their urine turns brown due to myoglobin staining the urine (Zimmerman and Shen 2013). At that point, the muscle cell is already dead and the kidneys are struggling to keep up with the toxic protein.
Seeing how often my friends are doing CrossFit makes me wonder if any of them have had rhabdomyolysis occur. It puts the question out there as to whether or not that type of intensive exercise is doing more harm than good for your body? I also wonder if CrossFit trainers are doing anything to help prevent their participants from rhabdomyolysis?
References:
Robertson E. 2013. CrossFit's dirty little secret. Health & Fitness. https://medium.com/health-fitness-1/97bcce70356d
Zimmerman JL, Shen MC. Sep 2013. Rhabdomyolysis. CHEST Journal. 144 (3)1058-1065.
I was wondering if any of your research indicated exactly how much is too much with CrossFit workouts. I know in general rest days are encouraged in most workout routines, and was curious if spacing out CrossFit workouts could help prevent rhabdomyolysis? Would this provide time for the muscle to recover?
ReplyDeleteI didn't realize someone did a post on this as well, cheers :)
ReplyDeleteI definitely think that this is something that people should be more educated about. I do crossfit, but I have been doing the workouts since I was young, before it was an industry. I believe it is like anything in moderation. We need easy days and we need to listen to our bodies. There is a difference between pushing to improve and pushing to damage. I have had to learn this with college cross country.
What shocks me though is that they have a cartoon about it, that definitely need to change, because I have seen sweatshirts with it as well.
Has there been research to show that Rhabdomyolysis is cause solely by muscle figure and “working out too much”. I know that CrossFit has the underlying principle of high intensity/high repetition interval training. So is it the high repetitions and little rest in between sets and workouts (overtraining) that is the major factor of Rhabdomyolysis? I wonder how much of a factor bad weight lifting form/techniques plays into injury and the cause of Rhabdomyolysis. I know that CrossFit includes explosive style Olympic lifts where proper form is crucial. However, as the workout continues, many CrossFit practitioners start to lose good lifting form and are just trying to reach a certain number of reps, thus straining muscles with improper motions. Any thought on which is the deciding factor that might exacerbate the onset Rhabdomyolysis—overtraining or improper lifting techniques?
ReplyDeleteIt seems that the mortality rate for rhabdomyolysis is quite high and the treatment for it long and rigorous. (1) Do you know if there is a higher susceptibility of getting rhabdomyolysis again if you have had it before? Also is there any research going on about why rhabdomyolysis mainly seems to be associated with CrossFit, and military training? If rhabdomyolysis is an exertion injury how come it is not very prevalent in professional sports, where the athletes are put through intense exercise regularly?
ReplyDelete(1) Splendiani, G., Mazzarella, V., Cipriani, S., Pollicita, S., Rodio, F., & Casciani, C. (2001). Dialytic treatment of rhabdomyolysis-induced acute renal failure: our experience. Renal Failure, 23(2), 183-191.