Lauren Peterson figured taking a spin class would be a great way to get in shape. But after less than 15 minutes of intense pedaling she felt nauseous and nearly passed out.
Two days later the 33-year-old Bronx schoolteacher’s urine had turned dark and the muscles in her thighs had become swollen and excruciatingly painful.
“I was crying putting on my socks, my thighs hurt so bad,” Peterson said. “I was scared. I knew something was really wrong with me. I didn’t know what it was.”
When Peterson went to the emergency room a couple of days later and got diagnosed, doctors told her she was lucky she hadn’t severely damaged her kidneys.
Peterson, a novice spinner, had developed the potentially fatal condition known as rhabdomyolysis. One of Peterson’s doctors described her case, as well as those of two other young adults who showed up at the Westchester Medical Center, with similar symptoms, after a spin class.
“Spinning is great exercise,” said Dr. Maureen Brogan, the lead author of the recent report detailing Peterson's case, and a kidney specialist at Westchester Medical Center. “But people should be aware they need to take it slow in the beginning. There should be some guidelines.”
The problem with spinning, Brogan explained, is that “you’re using some of the largest muscles in the body — the quadriceps and the gluteus maximus — at an intense rate.”
If exercise is too intense, the muscles may not get enough oxygen and then they can start to “swell and break down and burst open,” Brogan said. “When the muscles break down, they release proteins that can potentially hurt the kidneys.”
Over the course of two years Brogan and her colleagues saw a total of six cases of spinning-related rhabdomyolysis. One other young woman, also 33 at the time she developed the condition, ended up in kidney failure and needed to be on dialysis for a month until the organs recovered.
Brogan suspects that there may be more cases out there that were mild enough that people didn’t seek medical care. She’s hoping that her report will increase awareness of the dangers associated with overly intense workouts.
She offered a list of symptoms that should send someone to the doctor:
- Extreme muscle soreness
- Fatigue, nausea and vomiting
- Thigh pain and weakness
- Dark urine and decreased urine output
- Muscle swelling and tenderness
Peterson believes she’s very lucky. She wasn’t sure what she should be doing about the pain and weakness she was experiencing, so she called a doctor friend — Brogan — for advice. Brogan urged her to get to the hospital as quickly as possible, fearing that Peterson’s symptoms might mean her kidneys were in danger.
Though she needed months of physical therapy to regain strength in her thigh muscles, Peterson is nearly back to normal now.
While it's important to know the symptoms of rhabdomyolysis, Dr. Susan Quaggin stressed that she doesn’t want people to become so scared they stop working out.
“Lots of people spin and we’re not seeing an epidemic of people coming to the hospital with rhabdomyolysis,” said Quaggin, chief of the department of nephrology and hypertension and director of the Feinberg Cardiovascular Research Institute at Northwestern University. “We don’t want hysteria. We don’t want people to stop doing exercise.”
Quaggin would like to see instructors counsel novice spinners to take it easy in the beginning. Rhabdomyolysis is less likely if people are fit, she said.
She also reminded spinners to make sure they stay hydrated and to talk to their doctor if they start to develop any warning signs.
“There’s a big risk if you don’t seek medical attention,” she said. “Electrolyte imbalances can be fatal, particularly potassium which is released into the bloodstream when muscle cells break down. Potassium can then go very high and can cause the heart to stop.”
Be aware of the symptoms outlined above, and call your doctor if you experience them. And remember, if you're new to spin, take it easy. Don't push yourself to extremes just to keep up with everyone else.