After just 15 minutes in a spin class, Lauren Peterson began feeling nauseous and almost passed out. Though she initially brushed off the symptoms as the result of a particularly intense session, two days later, her urine had turned dark and her thigh muscles had become swollen and painful.
"I was crying putting on my socks, my thighs hurt so bad," she told TODAY. “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, she found out that she had developed rhabdomyolysis, a potentially fatal condition in which the skeletal muscle rapidly deteriorates. It can be caused by either internal or external injury, and can result in kidney failure. In fact, doctors told Peterson that she was lucky she hadn't severely damaged her kidneys by the time she went to the emergency room.
So can spinning really cause this condition?
"Spinning is great exercise," Maureen Brogan, MD, the lead author of a report detailing Peterson's case, told TODAY. "But people should be aware they need to take it slow in the beginning. There should be some guidelines."
According to TODAY, the doctors had recently seen two other young adults at the Westchester Medical Center who had also shown similar symptoms after a spin class.
The issue with spinning, Dr. Brogan told TODAY, is that "you’re using some of the largest muscles in the body — the quadriceps and the gluteus maximus — at an intense rate." If the exercise is too intense, she said, the muscles might not get enough oxygen, and can swell up and break down and burst open.
"When the muscles break down, they release proteins that can potentially hurt the kidneys," Dr. Brogan said.
She also said that while she and her colleagues have seen six cases of spin-related rhabdomyolysis, she suspects there have been more mild cases that have gone unrelated. Of course, that's not to say that you shouldn't keep spinning if you love it.
That being said, Brogan said it's important to stay hydrated and be aware of symptoms, such as extreme muscle soreness, nausea/vomiting, thigh pain/weakness, dark urine, and muscle swelling and tenderness. The bottom line? Do whatever exercise you feel comfortable with, but don't forget to pay attention to your body and listen to what it needs.