Update: Exertional rhabdomyolysis, active component, U.S. Armed Forces, 2011.

In 2011, there were 435 incident episodes of rhabdomyolysis likely due to physical exertion and/or heat stress ("exertional rhabdomyolysis") among U.S. service members. The annual rates of exertional rhabdomyolysis nearly doubled from 2007 to 2011. The highest incidence rates occurred in males, black, non-Hispanics, service members younger than 20 years of age and in the Marine Corps and Army. Most cases were diagnosed at installations that support basic combat/recruit training centers or major Army and Marine Corps combat units. Medical care providers should consider exertional rhabdomyolysis in the differential diagnosis when service members -- particularly recruits -- present with muscular pain, swelling, limited range of motion, or the excretion of dark urine possibly due to myoglobinuria after strenuous physical activity, particularly in hot, humid weather.