This is part one on a series that we’re doing on rhabdomyolysis. Rhabdomyolysis (or rhabdo for short), is something that every athlete, novice or beginner should be aware of. There are a lot of myths out there in the fitness world involving rhabdomyolysis from what causes it to how it’s treated. Hopefully this clears up some of the air.

Rhabdo Myths Online

I was inspired to write this post after reading on online forum in regards to rhabdomyolysis. One of the commentators was under the impression that pullups — yes, PULLUPS! can cause rhabdomyolysis. To be clear here – a specific muscle movement never cause rhabdo. Unless of course you do hundreds of that type of exercise or you have never worked out that muscle before and over-exert yourself. Alright, now that I got that rant out of the way…

What Is Rhabdomyolysis

To keep it short and simple, rhabdomyolosis is the breakdown of muscle proteins. It can be caused by a variety of situations, everything from laying in one position for too long, metabolic issues, lack of oxygen to muscle tissue, and over-exertion. For the case of this series, the focus is going to be specifically on one type of rhabdo which is known as exertional rhabdomyolysis.

Exertional Rhabdomyolosis:

Exertional rhabdomyolosis is a type of rhabdo that results from one overall theme: overexertion. This happens in individuals where the energy can no longer meet the demands of the muscles (non-traumatic).

What Happens To Your Muscles When You Get Rhabdo:

The overall picture is a pretty simple to grasp. The energy supply inside your body is far greater than what can be supplied to your muscle tissue. Eventually your skeletal muscles become damaged and start to break down. As they breakdown they start releasing muscle proteins into your bloodstream and some of these proteins are toxic to your body. This specific protein is called myoglobin. The problem is that your kidneys don’t really like myoglobin – at all. In fact, they hate it. It damages them – pretty bad too. It’s not uncommon for people to go into acute kidney failure after rhabdomyolysis. With your kidneys not working, toxins can build up in your blood and, well, as you can imagine, that’s not a good thing.

Causes Of Exertional Rhabdomyolysis

Causes of rhabdomyolysis are pretty easy to identify and be caused by all or just one of the things below.

Overexertion:

You don’t run a marathon the first time you exercise, right? Unfortunately, far too many people who are not conditioned attempt workouts that their body can’t handle. Being aware of your current fitness level is something that you as a person need to take responsibility for. If you’re looking to increase your conditioning and cardiovascular fitness levels, you need to scale it appropriately for what your body can do. This doesn’t mean trying to do fifty pull-ups if you’re only capable of five. You can still shoot for the stars, you just have to plan accordingly.

Hot Climates:

According to the research out there, there seems to be an association with hot climates, exercise, and rhabdomyolysis (heatstroke). Exertional heat stroke is common in younger, otherwise healthy people that participate in high temperature climates. Higher humidity climates also play a role as well as a risk factor for heat stroke and rhabdomyolysis (3,4). As your body’s temperature regulation mechanisms become impaired, your body temperature can continue to rise. High internal core temperatures can cause muscle proteins to “malfunction” and become damaged, leading to skeletal muscle breakdown. Heat stroke can also cause other things like excess sodium and potassium loss which brings me to my next point…

Electrolyte Imbalances:

In an athlete, or even a person new to working out, nutrition is more important than the workout. If your workout is vigorous enough, you’re going to lose electrolytes through sweat. If you didn’t have enough electrolytes to begin with or you haven’t been replacing them, then it can be an issue.

Potassium: Potassium plays in important role in the way your muscles get their bloodflow (see oxygen and nutrients). As your muscles contract they release potassium from muscle cells. This in turn causes your blood vessels to open up and provide additional blood flow. It also aids in muscle contraction. However, as you sweat, you lose potassium. As a result, there is less blood flow which impairs muscle contraction, can lead to cramps, and can help promote rhabdomyolysis from lack of energy supply to the muscles (3).

Hyponatremia: Hyponatremia, or low sodium is another electrolyte lost during excessive workouts. Low sodium levels play a role in muscle contraction and together with low potassium levels, can inhibit the ways muscles function, increasing the risk for rhabdomyolysis (5).

Symptoms Of Rhabdomyolysis

It’s all in the urine. One of the most common symptoms of severe rhabdomyolysis is reddish/brown urine. This is caused by the breakdown of muscle tissue in your body that is being filtered out by your kidneys. Eventually that broken down muscle tissue has to go somewhere – and that’s in your pee. So if you start noticing some funky colored urine, you should probably go to urgent care/the emergency department because there’s a good chance you might have renal failure.

Once you’re at urgent care or the emergency department and after you have your blood drawn, if you have high creatine kinase (CK) levels, it’s likely indicative of of rhabdomyolysis as well. CK is another by product of injured muscle tissues and is highly elevated with rhabdomyolysis. Normal levels are anything less than 150 (depending on your lab). With rhabdo you can see CK levels of anywhere from 20,000 to higher than 40,000.

Physical symptoms of rhabdomyolysis might include muscle failure (during the time of exercise), muscle pain, muscle stiffness, muscle cramping, and muscle weakness. However, more than half of rhabdomyolysis patients, may not even report muscular symptoms at all. In some cases, swelling near the site of muscle injury, blisters, or skin discoloration will be present as well. Additional symptoms might include general sickness, fever, rapid heart rate, nausea, vomiting, and, abdominal pain (1,4,5).

Renal Failure and Rhabdomyolysis:

One of the most common complications of rhabdomyolysis is acute renal failure. As we’ve talked about, this happens from the passing of myoglobin which is physically damaging to the small filtering parts of the kidney. The lower your CK levels are, the less your risk of developing rhabdo is. In athletes, one factor that increases the risk is dehydration. Your kidneys hate dehydration. Fluid therapy for any athlete (even more so for hot/humid climates) is essential (1,4,5).

Other Complications:

Electrolyte abnormalities such as low sodium, low or high potassium, high phosphate, and low calcium levels can also occur while you’ve got rhabdo. As your muscle breaks down it releases cellular potassium into your blood stream. Normally it would be excreted by your kidness but if you’re one of the lucky ones that has acute kidney failure, your kidneys can’t make you pee it out so now you’ve got a problem of having high potassium. High potassium levels can lead to heart rhythm abnormalities and further muscle weakness. Electrolyte imbalances as a whole can contribute to further muscle weakness (1,4,5).

Diagnosing Rhabdomyolysis

Diagnosing rhabdomyolysis can be quite easy the problem is that it likely goes under diagnosed. Not all people with rhabdomyolysis will have brownish colored urine. Some people might also mistake muscle soreness as “just a part of the workout.” In any sense, rhabdo is something that athletes whether new to working out or experienced need to be aware of. If you’re experiencing any of the symptoms that were mentioned, consider going to an urgent care or emergency department to ensure there’s nothing wrong with your kidneys. In the next part of the rhabdomyolysis series we’ll be talking about rhabdomyolysis prevention and treatment – things you can do to help prevent rhabdomyolysis and what you can do to once you have it.


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Sources:

1. N.a. “Rhabdomyolysis.” Medline Plus. 2 Oct. 2013. Web. 14 July 2014.
2. Borchers, J., Tietze, D. “Exertional Rhabdomyolysis In The Athlete: A Clinical Review.” Sports Health Journal. 6 July 2014. Web. 14 July 2014.
3. Mechem, C. “Severe Nonexertional Hyperthermia (Classic Heat Stroke) In Adults).” UpToDate. 13 Sep. 2013. Web. 14 July 2014.
4. Miller, M. “Causes Of Rhabdomyolysis.” UpToDate. 1 April 2014. Web. 14 July 2014.
5. Efstratiadis, G., Kourkouni, E., Kyventidis, A., Nikiforou, D., Vergoulas, G., Voulgaridou, A. “Rhabdomyolysis.” Journal of Hippokratia. 11 July-Sep. 2007. Web. 14 July 2014