Lack of exercise is a health hazard, but too much exercise can be dangerous, too. Exertional rhabdomyolysis, a rare but serious condition that breaks down muscles and damages kidneys, strikes some exercisers who push their limits. Amateurs and athletes are both at risk, and the affliction doesn't discriminate on the basis of age and gender. But taking some precautionary measures can raise the odds that your workout will be safe.
Symptoms and Diagnosis
When rhabdomyolysis strikes and damages muscles, a muscle enzyme called creatine kinase, or CK, and a protein called myoglobin flood the bloodstream. The kidneys must filter the myoglobin, which can break down into dangerous compounds. Myoglobin shows up in the urine by turning it the color of Coca Cola. The brown urine, extremely elevated CK levels and intense muscle pain lead to a diagnosis of rhabdomyolysis.
Causes and Risk Factors
The causes of rhabdomyolysis include traumatic injury, alcoholism and drug addiction. But healthy exercisers who fall prey to exertional rhabdomyolysis are likelier to be predisposed by genetics, hot weather, or a sudden increase in the intensity of their workouts. According to the Athlete in Me website, Ashkenazi Jews are especially likely to have a genetic predisposition. Heat stroke is also closely associated with exertional rhabdomyolysis.
Case Studies
Rhabdomyolysis is unpredictable, sometimes striking athletes who are perfectly fit. The Athlete in Me website lists a few case studies. One is a 19-year old female college student who was diagnosed with rhabdomyolysis after playing Frisbee golf for three hours. Another is a 40-year-old man who got rhabdomyolysis in his biceps from doing negative curls. This maneuver involves starting with the forearms parallel to the floor, heavy barbell in hands. Instead of lifting the barbell up, as in a regular biceps curl, you lower the barbell until the arms are straight. This straightening is called an eccentric muscle contraction, and, according to the Athlete in Me, is especially associated with rhabdomyolysis. The Sports Injury Bulletin tells the sad story of a marathon runner who died of rhabdomyolysis when he was almost at the finish line. All of these are instances of exercisers working only somewhat more intensely than usual.
Prevention
Avoiding dehydration is one of the keys to escaping rhabdomyolysis. Dehydration reduces blood flow to the kidneys, increasing the chance of kidney failure, according to Chris McGrew, a sports medicine doctor at the University of New Mexico Hospital. Drink plenty of water throughout the day, and after exercising have a recovery drink with protein. Beware sudden increases in exertion, especially during hot weather.
Treatment and Prognosis
If you think you have rhabdomyolysis, seek medical help immediately. If tests confirm this diagnosis, doctors will order lots of fluids, possibly intravenously. Some patients need kidney dialysis. In milder cases, people can return to their activities within a few weeks, but muscle pain might linger.
