Crazy determination can get you to the Olympics—but apparently, it can also get you rhabdo. Rhabdo—short for rhabdomyolysis—is when a muscle gets so damaged that the tissue starts breaking down and muscle fiber contents are released into the blood. While people joke that they'll "catch" rhabdo by trying CrossFit, it's actually a really serious matter—just look at Paralympic snowboarder and DWTS alum Amy Purdy, who has been in the hospital the last five days with rhabdo after a grueling pull-up workout. (See, CrossFit isn't the only workout that can cause rhabdo.)
How rhabdo works: muscle breakdown releases a protein called myoglobin into the bloodstream and is filtered out of the body by the kidneys. Myoglobin breaks down into substances that can damage kidney cells often cause kidney damage, according to the National Institutes of Health (NIH).
Rhabdo is serious in most people; it can often cause acute kidney failure, and at the very least, people need to wait a few weeks or a month before returning to normal activity. Because Purdy has a kidney transplant, this is even more worrisome.
"This condition is so scary, please pay attention to your body," Purdy wrote in an Instagram post. "If you have overworked your muscles, if you are sore, and you can see some swelling even the slightest amount like I had, don't hesitate to go to the ER, it can save your life."
And the scariest part is that it can happen more easily than you think: "I have been training as I prepare for the snowboard season and 1 day last week I pushed myself too hard. It seemed to happen so innocently, I did a series of pull-ups and simply pushed too hard to complete the set," Purdy wrote in another Instagram. (And she's not the only one—a pull-up workout almost killed this woman too.)
She said her muscles were a bit sore, nothing out of the ordinary until she noticed some swelling in her arm. Since Purdy had a friend in the hospital with the same condition last year, she recognized the symptoms and knew she needed to go to the hospital, according to her Instagram. Fast forward five days and she says doing ok—but "beyond grateful for [her] life and health."
Rhabdo can be caused by low phosphate levels, lengthy surgical procedures, extreme body temperatures, trauma or crash injuries, and severe hydration, as well as workout-related causes like extreme exertion and general muscle breakdown, according to the NIH. Symptoms include dark-colored and decreased urination, muscles weakness, stiffness, and tenderness, as well as fatigue and joint pain.
"The people who are at risk [for rhabdo] are the fit ones who haven't done CrossFit and come in thinking they can go way too hard too early before their bodies have acclimated to the volume and intensity," as Noah Abbot, coach at CrossFit South Brooklyn, told us in The 12 Biggest Myths About CrossFit. (Worried about rhabdo? Use these physical therapist's tips for preventing injury when starting a high-intensity program like CrossFit.)
While it's heartbreaking to see an amazing athlete like Purdy come down with any scary health condition, her experience is a lesson for everyone; even professional athletes can get injured—or worse, something like rhabdo—during workouts. So repeat after us: listen to your body.