Runners and Exertional Rhabdomyolysis
What in the world is Rhabdomyolysis?
Rhabdomyolysis, (often referred to as Rhabdo) is a big word for a direct muscle injury and subsequent massive muscle breakdown. This muscle breakdown results in the release of muscle proteins that can overwhelm the kidneys, leading to kidney failure if not treated. Myoglobin is the protein that is released from the damaged muscle cells which essentially break off and “clog up” the kidneys. Rhabdo has several causes including extreme exertion, crush injuries, car accidents etc.
Why should you know about this as a runner/athlete? Although somewhat rare; Exertional Rhabdomyolysis (ER) is often seen in endurance athletes from exposure to extreme heat, dehydration, crushing/pounding/repetitive trauma. The combination of dehydration and extreme exertion puts the athlete at increased risk for glycogen deprivation and ultimately rhabdomyolysis. This process disturbs the bodies homeostasis and proper cell function which can lead to renal and cardiac disturbances. Other factors that may predispose an athlete for increased risk of ER include, working out/competing while experiencing a viral or bacterial infection, GI issues, flu, endocrine problems, or electrolyte imbalances. In other words, if you are sick while competing/training, your chance of dehydration and ER increase immensely!
Clinical studies have shown that NSAIDS (aleve, ibuprofen, aspirin) in combination with intense exercise and dehydration, interrupt the kidney’s ability to eliminate byproducts, thus leading to rhabdo. NASID’s have also been shown to indirectly alter blood flow within the kidneys, making them more prone to damage from the cell damage and breakdown. This association is by no means definitive, but endurance athletes should beware of the potential it presents!
So, what are the symptoms of ER? The classic triad of symptoms include muscle pain, general weakness, and very dark or red urine. Majority of athletes do not contribute muscle pain/weakness as symptoms/warning signs because they are expected, but almost half of those affected by ER do experience either red or extremely dark urine (resembling cola). While often mistaken for blood, the red coloring is actually the myoglobin protein, which is normally filtered out by the kidneys. Other symptoms may include increased heart rate, elevated body temperature and vomiting. If a combination of these symptoms is noticed (especially dark/red urine), the athlete should stop exercising and seek immediate medical attention.
Diagnosis is done through blood work, which checks for elevated levels of a muscle protein, creatine kinase (CK) and urine tests for myoglobin. When caught early, treatment for ER primarily involves intravenous rehydration. When not caught early, the athlete is at risk for acute renal failure and cardiac disturbances.
I speak from personal (second hand) experience, as my husband recently competed in the Eastern States 100 mile race but was medically tapped at mile 70 for ER. Thankfully, it was caught early and although he was hospitalized for 36 hours, treatment was only IV rehydration. Most athletes will never experience ER, but if you are an endurance athlete you should know the warning signs!
Stay hydrated. Run healthy. Run happy!
References:
Nance JR, Mammen AL. Diagnostic evaluation of rhabdomyolysis. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4437836/) Muscle Nerve. 2015 Jun;51(6):793-810. Accessed 12/5/2019.
The Myositis Association. Rhabdomyolysis. (https://www.myositis.org/about-myositis/complications/rhabdomyolysis/) Accessed 12/5/2019.
Vanholder R, Sever MS, Erek E, Lameire N. Rhabdomyolysis. (https://jasn.asnjournals.org/content/11/8/1553) JASN Aug 2000, 11 (8) 1553-1561. American Society of Nephrology. Accessed 12/5/2019.
