Acute, exertional rhabdomyolysis typically follows strenuous exercise of the eccentric type, such as that which occurs during military training or repetitive weight lifting in unconditioned individuals. Complications can be significant and include compartment syndrome and acute renal failure due to myoglobinuria, especially in the setting of volume depletion. Rhabdomyolysis may also be precipitated by viral infections, usually influenza virus. I report an unusual case of a female patient who had acute rhabdomyolysis, complicated by compartment syndrome of both legs, after beginning an exercise regimen on a treadmill. The patient reported a viral-like illness several days before and was found to have a rise in antibodies to coxsackieviruses B4 and B5.