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Exertional Rhabdomyolysis: Definition, Causes, and Dangers

What is Exertional Rhabdomyolysis?

Exertional rhabdomyolysis is muscle breakdown caused by extreme physical exertion, typically from working out too much. This breakdown releases muscle content (e.g., creatine kinase and myoglobin) into the bloodstream, putting people at significant health risks, including kidney damage. Symptoms include muscle weakness, stiffness, and tenderness, as well as dark-colored urine, and persistent fatigue.

What Causes Exertional Rhabdomyolysis?

The most common cause of exertional rhabdomyolysis (also known as ‘rhabdo’) is significant physical exertion, typically in the form of too much exercise, be it cardio, weight training, or a combination of the two.

Physical exertion causes excessive muscle damage, causing tissue breakdown and the release of creatine kinase and the protein myoglobin into the bloodstream, often leading to kidney damage.

Blood electrolyte levels can also become too high, increasing the risk of irregular heartbeat or even cardiac arrest. The latter happened to Aaron Kuen, a marathon runner, who suffered a cardiac arrest resulting from rhabdo.

Dehydration, undereating (and not getting enough protein), and exercising in hot environments can increase the risk of exertional rhabdomyolysis.

How to Reduce the Risk of Exertional Rhabdomyolysis

As a coach, a big part of your job is to create workout plans that challenge clients enough to spark progress without overwhelming and overtraining them. This means accounting for the client’s goal, work capacity, stress, and activity level outside structured exercise time.

The most reliable way to avoid exertional rhabdo is to create moderately challenging workout plans, explain the danger of too much exercise to clients, and tell them that more is not necessarily better.

It’s best to monitor your clients’ performance and collect feedback on:

  • How difficult the workout plan feels
  • How persistent and severe the muscle soreness is
  • Whether they can handle the training and make steady progress

Additionally, encourage clients to drink enough fluids (Mayo Clinic guidelines suggest around 2.7 liters for women and 3.7 liters for men, but the ideal amount can vary) and to eat enough calories to maintain their body weight or lose no more than 0.5-0.7% of their body weight weekly.

On that note, adequate protein intake and a diet based on whole foods (for adequate vitamin and mineral intake) are also highly beneficial.


1. Who is at risk of developing exertional rhabdomyolysis?

People who do intense physical training (particularly those in the military and those training for marathons), people with certain genetic predispositions, and those who do not eat a healthy diet or drink enough liquids are at a higher risk of exertional rhabdo.

2. Can certain exercises increase the risk of rhabdo more than others?

Activities that cause significant muscle damage, particularly in large muscle groups like the lats and quadriceps, could place athletes at a slightly higher risk of rhabdo if overdone. Eccentric-focused training can also be more damaging to the muscles.

3. How is exertional rhabdomyolysis diagnosed?

Rhabdo is typically diagnosed with blood tests showing elevated levels of myoglobin and creatine kinase following a period of exhausting training accompanied by symptoms (e.g., persistent and noticeable muscle pain).

4. Can exertional rhabdomyolysis occur without causing pain?

The CDC suggests that rhabdo can occur without symptoms and some research from Torres (MD) et al. suggests that over 50% of patients with rhabdomyolysis don’t complain of muscle weakness or pain.

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