It was a seemingly normal workout: a high-powered circuit of pull-ups, push-ups, and squats. "Difficult, yes, but done in 20 minutes," says Shari Becht, a 40-year-old chef in Highland Ranch, Colorado. Seventy-two hours later she knew something was seriously wrong. "I couldn't believe how big and heavy my arms looked," she says. They were so swollen and sore she could barely straighten them, and her fingers tingled. Worried, Shari rushed to her doctor, who did blood work. "The next afternoon, I got a call saying, 'We have a hospital bed waiting for you,'" she remembers.
Shari was diagnosed with exertional rhabdomyolysis, a condition brought on by intense activity in which muscle fibers break down and release electrolytes and proteins into the bloodstream. One of the proteins, myoglobin, can occur in such high concentrations that it overwhelms the kidneys, which can lead to kidney failure or death. Shari spent three days in the hospital hooked up to a saline IVRead More »from Workouts Gone Wrong: Ways to Injury-Proof Your Sweat Sessions