You’ve certainly heard the expression “no pain, no gain,” but there’s such a thing as pushing it too hard in your workouts. And the consequences can go far beyond sore muscles and fatigue. Athletes who overexert themselves to an extreme point can develop a condition called rhabdomyolysis, a breakdown of muscle tissue that can lead to kidney failure, heart damage, and even death.
Although relatively rare, rhabdo affects approximately 26,000 people in the United States each year. Athletes who do high-intensity or extreme endurance workouts are often among those who feel the effects of rhabdo.
Last October, Paralympic snowboarder Amy Purdy was hospitalized for it; and one month earlier eight student athletes from Texas Woman’s University were also sent to the hospital with signs of the condition.
What causes it?
High-endurance activities involving heavy lifting can increase the risk of rhabdo, as can other forms of over–exertion or trauma, says S. Adam Ramin, M.D., a urologic surgeon and medical director of Urology Cancer Specialists in Los Angeles. But while CrossFit is sometimes blamed for causing rhabdo, research shows CrossFitters are no more likely to develop it than powerlifters, gymnasts, or rugby players.
Any intense exercise puts a strain on muscles. When that strain exceeds what you can handle, your muscle fibers may tear open, spilling a protein called myoglobin that would normally transport oxygen to your muscle cells into the bloodstream. As a result of this spillage, the torn muscle can rapidly deteriorate, while the kidneys can become overwhelmed by rising myoglobin in the blood.
Athletes who perpetually push themselves past the point of fatigue or who do an exercise to muscle failure during the eccentric (negative) phase and then go on to do additional high-intensity exercises can develop this dangerous muscle breakdown. Trying to cram in your fitness (doing an extreme amount of exercise in a short amount of time) can also take its toll.
Hydration also plays a part. Research shows that when muscle cells are deprived of adequate water, they shrink and become more vulnerable to breakdown. In addition, alcohol consumption or excessive levels of caffeine can lead to rhabdo. Other culprits include infections like influenza or conditions like herpes or sickle cell anemia and even certain medications such as antihistamines, antidepressants, statins, and acetaminophen.
How you’ll feel
Fatigue and achy muscles are the usual first signs of rhabdo, says Steve Yoon, M.D., director of orthobiologics and regenerative medicine at the Kerlan-Jobe Orthopedic Clinic in Los Angeles. Other hallmarks include swollen limbs, brown-colored urine, nausea, vomiting, and fever.
Symptoms appear within a few hours to a couple of days after a traumatic injury or extreme workout. Levels of the electrolytes’ sodium and potassium become unbalanced and a buildup of the nitrogenous compound urea occurs in the blood if kidneys begin to fail, leading to confusion and heart palpitations.
If you notice these conditions—especially swollen body parts and/or darker-than-normal urine—seek immediate medical attention. Treatment includes an intravenous saline solution that helps to flush excess myoglobin from the bloodstream, rehydrating the body’s cells, and relieving stress on the kidneys. In extreme cases, dialysis may be required to prevent kidney failure. And if a muscle group is experiencing a prolonged loss of circulation, doctors may surgically relieve pressure.
If you’re just feeling achy and fatigued, try to see your health-care practitioner within two days to test your blood for high levels of creatine kinase, a biological marker of rhabdo. “There are differing levels of rhabdo,” Ramin points out. “It may be very self-limited and require minimal medical support. Or it may be very serious, leading to kidney failure.”
Trying to cram in your fitness or always pushing past fatigue can take a toll.
Since dehydration plays a role in rhabdo, it’s important to make sure your body is getting enough fluids, advises Luga Podesta, M.D., director of sports medicine at St. Charles Orthopedics in Setauket, NY. The American College of Sports Medicine recommends drinking 16oz to 20oz of fluid at least four hours before any workout that lasts up to an hour, and 8oz to 12oz within 15 minutes of beginning it. For every 15 minutes you exercise to the point of sweating (even mildly), throw back 3oz to 8oz of water. If your exertion exceeds an hour, have 3oz to 8oz of a sports drink to balance out your electrolytes.
But most important, listen to your body. “If you can’t maintain proper form during a weight routine, or you feel faint, dizzy, or can’t catch your breath during cardio, scale down your pace, load, or intensity,” says Nathaniel Oliver, a trainer and founder of Type A Training in New York City. And don’t be afraid to take it easy now and then. “One week a month, try to modify your workout,” he adds. Regularly scaling back intensity will help you get stronger and ensure that overtraining won’t keep you from performing at your best.