What Is Rhabdomyolysis?

Q: I’ve just started a high-intensity exercise program and keep hearing about the dangers of rhabdomyolysis. What is it? Should I be worried?

A: Rhabdomyolysis, or “rhabdo,” is a potentially deadly condition that can result from extreme overexercising.

“When individuals tax themselves to the breaking point, in rare cases, muscle tissue can start to die,” says Byron Patterson, MD, a team physician for the L.A. Galaxy soccer team and medical director of Primary Care Sports Medicine in Encino, Calif. Spent muscle tissue enters the bloodstream and releases a protein called myoglobin, stressing the kidneys and sometimes causing them to fail.

Rhabdomyolysis feels different from the soreness that can occur during a productive workout. “The muscles become extremely painful, and swell up within a few hours of the workout,” says Patterson. “Your urine turns dark from the protein filtered from the blood, which can lead to fever or nausea.” If you experience these symptoms during or soon after exercising, get medical help immediately.

To avoid this dangerous condition, always progress your workouts gradually and listen to your body. “Intense pain is an indication that you’ve done something wrong,” says Patterson. “Don’t try to work through it.”

On the other hand, don’t let the slim chance of contracting the condition scare you from getting a good workout. Most people are able to differentiate between good-for-you muscle soreness and intense pain.

“Usually, it shows up in competitive personalities and underconditioned athletes who are coming back to exercise after a long layoff,” says Patterson. “They remember where they used to be and try to get back there too fast.”