While Pukie the Clown is the unofficial mascot of CrossFit, depicted by a ripped clown barfing his guts out after an intense workout, there is a lesser known cartoon character and associated ailment some call “CrossFit’s Dirty Little Secret”.  Uncle Rhabdo (shown above) is a worn out clown standing in puddle of his own blood, disemboweled intestines and kidney hanging down, hooked up to a dialysis machine with open muscle tears all over his body.  Rhabdo is no secret, and the naysayer’s attempts to label it as a byproduct of any CrossFit workout are nothing more than those in opposition to CrossFit-style workouts slinging mud.  Rhabdo is rare, with only about 26,000 reported cases in the U.S. annually, but it is a serious condition that you should be aware of, and be able to recognize its causes and symptoms.

Rhabdomyolysis, pronounced Rab-dough-my ole-liss-sis, or Rhabdo for short, can be caused by many issues, but our interest for this article will concentrate on Exertional Rhabdomyolysis.  Exertional Rhabdo occurs when skeletal muscles are worked beyond fatigue to the point they essentially burst and release a protein called myoglobin into the bloodstream.  Myoglobin is toxic to the body once in the bloodstream, and your kidneys work to filter it out of your system.  At the same time, blood flow is routed to the damaged muscle tissue and this causes severe swelling at the injury site.  Myoglobin can clog up the kidneys and things get pretty serious at this point.  While only 5% of Rhabdo cases are fatal, proper treatment usually requires hospitalization.

Let’s look at the causes and symptoms of Rhabdomyolysis.

In many sources, you will see it stated that excessive exercise or weightlifting can cause Rhabdo. This is not completely accurate. In cases where people get Rhabdo, they are often engaging in high rep counts with light weights in rapid movements. Interestingly, heavy lifts don’t usually cause development of Rhabdo.  This is likely because the heavy weight causes you to slow down during the lift and rest afterward.  Exercises that are more likely to have a risk for causing Rhabdo are eccentric ones, where a muscle is stretched under load, such as lowering into the bottom of a squat.


This well-publicized instance of Rhabdomyolysis, is a great case to review to better understand it.  

In January 2011, University of Iowa football players were returning from a three-week winter break. Their first workout was 100 back squats at 50% of their 1 rep max, followed by a series of sled pushes, all done as quickly as possible.  One freshman called his father after the workout and told him he did 100 squats at 240 pounds in 17 minutes.  The student said he was unusually sore immediately after the workout, to the point he couldn’t walk, and he fell down some stairs.   Other teammates reported similar soreness.  The next day, they did an upper body workout with a similar rep scheme, followed by the weekend off.  That Monday was a lighter workout consisting of calisthenics and stretching.  By Monday night, 13 of the 85 football players that participated in those three workouts were hospitalized with Rhabdomyolysis.

Examining this case helps explain some of the causes of Rhabdo, while also showing how Rhabdo can be prevented.

High reps in a short time period.  100 squats for time is tough enough.  Doing it with 240 pounds is crazy.  Then sled work.  They crushed their leg muscles.

Heavy exertion after a lengthy absence in the gym.  Doing this series of high intensity workouts right after return from break set these players up for increased risk of injury. It is important to ease back into things if you’ve been out of the gym for a while.  Also, if you’re not ready for a heavy load, scale as necessary.

Ego.  While exercising in a group can be motivating, things can go south if a coach isn’t closely monitoring you.  Likely, these players were trying to outdo each other.  Their egos probably sent them to the hospital.  Proper coaching may have been able to recognize that the players were overworking themselves before injury occurred.

The perfect storm.  The unlikely straw that broke the camel’s back?  Stretching.  Having the two grueling workouts followed by the stretching session likely caused the perfect combination of events to let Rhabdo strike.  When you do an intense stretching session on already severely swollen muscles, you can facilitate the release of myoglobin.

Even though this was a tough series of events and workouts for the team, only 13 out of 85 athletes ended up in the hospital.  Why? Many things factor into who gets and who doesn’t get Rhabdo.  Level of fitness, degree of exertion, and hydration level, among other things can mean one person gets Rhabdo where another doesn’t.  Some causes are just unknown.


Is it Rhabdo?  There is an important distinction to be made between normal soreness and extreme muscle fatigue.  It is normal to feel sore after a workout, and that is a sign that you worked yourself hard.  This soreness will often show up about 24 hours after the workout and should start to subside after you start moving again.  However, if you feel extreme fatigue during the workout or immediately after, and this presents with muscle cramps or vomiting, that might be a bad sign. Also, people with Rhabdo will sometimes see puffy and saggy muscles in the affected area, where there once was firm muscle.  The big symptom to look for is brown urine.  If you are seeing an unusual degree of fatigue and have dark urine, especially if the color doesn’t change no matter how much water you drink, get to a hospital.

Here are some things to keep in mind to prevent Uncle Rhabdo from making a visit.

Hydrate.  Staying hydrated has so many benefits, not the least of which is keeping the muscle fibers pliable and promoting good blood flow.  Both are things you want to have to keep Rhabdo from occurring. Monitor your urine color.  Drink until you pee clear is a common suggestion that works.

Listen to the coach.  Our coaches are there to monitor you and make corrections.  Listen to them and follow their suggestions.  They are here to keep you safe and make sure you get the most out of your workouts.  Don’t get frustrated if they suggest you scale something.  Also, at times, we build rest periods into our WODs.  Make sure you are getting the whole rest period in. 

Don’t overdo it.  I have a friend who was hospitalized with Rhabdo.  However, he was doing both CrossFit and training for a marathon.  We design our WODs to be challenging and safe, but we don’t know what you are doing outside the Box.  A bit of running here and there isn’t going to be a problem, but if you are doing your own intense training program outside of what you do inside the Box, you may be pushing too hard.

Listen to your body and take planned rest days as needed.  If you are training for something and doing CrossFit, let us know.  Talk to Dave or Amanda so that your overall plan allows you to reach your goals safely.

If you’ve been away for a while, ease back into it.  Don’t expect to have the same one rep max you did after three months of doing no workouts. 

Don’t be afraid to put some weight on the bar.  If you are consistently crushing the times with a light weight, consider increasing the load.  The heavier weight will cause you to slow down a bit.  This is WOD-dependent, so ask a coach if you are unsure.

Certain drugs can increase your chances of developing Rhabdo. There are over 150 illicit and prescribed medications that may cause an increased risk of a person coming down with Rhabdo.  One of the more commonly prescribed drugs that could pose an increased risk for Rhabdo are statins taken for cholesterol control.  While statins may be no more likely to cause Rhabdo than any other medication, their widespread use bears mention.  If you are taking any medication, ask your doctor to see if it might be on the list of drug-induced Rhabdomyolysis medications.

While Rhabdomyolysis is a serious condition, obesity, heart disease, and diabetes kill far more people than Rhabdo does.  Just because there is a tiny chance of developing Rhabdo doesn’t mean you should hang up your minimalist shoes and booty shorts forever.  Following the prevention tips above while monitoring yourself is your best bet to keeping the odds in your favor, and keeping that dirty little secret just a disgusting cartoon drawing.