> 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 hos

> 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. Terrifying.