KILLER WORKOUT
Healthy people are being hit by a rare but life-threatening condition. While many intense forms of exercise can cause rhabdomyolysis, it almost always strikes those who are doing something new. Anahad O’Connor reports
Three years ago, Christina D’Ambrosio went to her first spin class, pedalling fast on a stationary bike to the rhythms of popular music as an instructor shouted motivation. But D’Ambrosio, who exercises regularly, found the hour-long class was harder than she anticipated. By the end her legs were sore and wobbly.
“I thought my body just wasn’t used to that kind of muscle ache because it was my first class,” says
D’Ambrosio, a nursery school teacher from Pleasantville, New York. Over the next two days, her legs throbbed with excruciating pain, her urine turned a dark shade of brown, and she felt nauseated. Eventually she went to a hospital, where she was told she had rhabdomyolysis, a rare but life-threatening condition often caused by extreme exercise. It occurs when overworked muscles begin to die and leak their contents into the bloodstream, straining the kidneys and causing severe pain.
After a two-week hospital stay, D’Ambrosio was released and has since recovered. Her case was highlighted in The American Journal of Medicine in April along with two other cases of spinning-induced rhabdomyolysis treated by the same doctors. The report noted that at least 46 other cases of people developing the condition after a spin class were documented in medical literature, 42 of them in people taking their first class. The report cautioned that the condition was very rare, and not a reason to avoid high-intensity exercise. But the authors said their goal was to raise public awareness so that people who begin a tough new workout programme will ease into it to lower their risk of injury.
“I would never discourage exercise ever,” says Alan Coffino, the chairman of medicine at Northern Westchester Hospital in Mount Kisco, New York, and a co-author of the new study. “Spin class is a great exercise. But it’s not an activity where you start off at full speed. And it’s important for the public to realise this and for trainers to realise this.”
Rhabdo, as many experts call it, has long been documented among soldiers, firefighters and others whose professions can be physically demanding. A US army study in 2012 estimated that about 400 cases of the condition are diagnosed among active-duty soldiers each year. On occasion there have also been large clusters of university athletes hospitalised with it after particularly gruelling workouts.
These are people who are not unfit – they are being pushed too hard, and they’re not trained to do this
But doctors say they are now seeing more of it among weekend warriors driven in part by the popularity of high-intensity workouts. Spinning in particular has gained a huge following; large chains like FlyWheel, SoulCycle and others report millions of rides and tens of millions in annual sales in the US. Studies show that high-intensity exercise offers a myriad of health benefits, but for a small subset of people, many of them beginners, rhabdo can crop up and quickly turn ugly.
In 2014, doctors at NewYork-Presbyterian Weill Cornell Medical Centre published a report on two patients who arrived at the emergency room with rhabdo shortly after their first spin class. One was a 24year-old woman hobbled by pain, her legs swollen and feeling “as tight as drums”. She was rushed to surgery, where doctors sliced her thighs open to relieve a dangerous build-up of pressure.
Another study found that between 2010 and 2014, there were 29 emergency room visits for exerciseinduced rhabdo at NewYork-Presbyterian alone. Weightlifting, CrossFit, running and P90X were the reasons for some visits. But the most common one was spinning. Dr Todd S Cutler, an internist at the hospital and lead author of the study, said the patients all fit a similar profile. “These are people who are not unfit,” Cutler says. “They are being pushed too hard, and they’re not trained to do this, and so they get really bad muscle trauma.”
There is some evidence that certain medications, including statins, stimulants and antipsychotic drugs, as well as genetic susceptibilities may contribute to the condition, says Patricia Deuster, a professor of military and emergency medicine at the Uniformed Services University of the Health Sciences in in Bethesda, Maryland. But in general it occurs when people simply do not give their muscles time to adjust to an aggressive new exercise, experts say.
A little damage to muscles is a good thing because that stimulates them to grow and adapt to stress. But when the stress is too great, fibres are destroyed. When that happens they break apart and release compounds that can be harmful to the liver, such as a protein called myoglobin, which causes brown or tea-coloured urine, a classic symptom of rhabdo.
While almost any intense activity can cause rhabdo, it almost always strikes people who are doing something new. That is why people should always progress from light to moderate and then vigorous intensity when doing a new exercise, says Eric Rawson, chair of the department of health, nutrition and exercise science at Messiah College in Pennsylvania. “You can be fit, and I can come up with a workout that you are unaccustomed to, and that could be what causes rhabdo,” he says. Even elite athletes are not immune. Amy Purdy, a bronze-medalist Paralympic snowboarder, went to an exercise class last year after taking three weeks off from training. The class consisted of a circuit of challenging exercises, she says, including dozens of pull-ups. “About halfway through I realised my arms were completely fatigued,” she says.
They kept doing what the instructor told them to do because they did not want to look weak
The next morning she could not straighten her left arm. Then it became sore, stiff and swollen, prompting her to go to hospital. She remained there for eight days as doctors flushed her kidneys with water, she says. She was diagnosed with rhabdo, and when she wrote about the experience on social media she was
inundated with responses. “Thousands of people have reached out to me on my Instagram page who have had it as well,” she says. “Almost everyone was fit before, got it from pull-ups and is trying to figure out the way to get back into fitness without risking a recurrence.”
Two things can help you avoid rhabdo, says Joe Cannon, an exercise physiologist. Before starting a new programme, do a less intense version of it first. That means riding a stationary bike at a moderate pace before starting a spin class, or doing just one set of a weight lifting exercise rather than multiple sets and repetitions. But the most important advice is to know your limits: don’t be afraid to leave a class or to say no to a trainer if you are struggling.
“One thing I’ve noticed when people tell me they’ve gotten rhabdo in the gym is that they gave up their personal power,” says Cannon, author of Rhabdo: The Scary Side Effect of Exercise You’ve Never Heard Of. “They kept doing what the instructor told them to do because they did not want to look weak.”
That was the case for Nancy Weindruch, a communications executive at the Council for Responsible Nutrition, a trade group in Washington. In 2015, Weindruch, who exercised regularly, attended a spin class with her sister, but was not prepared for the instructor’s fast pace and directions to “push past your limits”. “It went from zero to 60 very quickly,” she says. “Within minutes I knew that I was in over my head. But I swallowed my pride and kept going.”
Three days later, after unbearable pain in her legs, she was admitted to a hospital with rhabdomyolysis and was kept there for six days. Weindruch eventually returned to exercise, but now she sticks to activities like walking, yoga and the cross-trainer. “I never thought that exercise could be dangerous,” she says. “But it can be when your body is not prepared for really intense levels.”