Update: Exertional rhabdomyolysis, active component, U.S. Armed Forces, 2015-2019

Among active component service members in 2019, there were 512 incident cases of exertional rhabdomyolysis, for an unadjusted incidence rate of 38.9 cases per 100,000 person-years (p-yrs). Subgroup-specific rates in 2019 were highest among males, those less than 20 years old, non-Hispanic black service members, Army or Marine Corps members, and those in "other/unknown" or combat-specific occupations. During 2015-2019, crude rates of exertional rhabdomyolysis fluctuated between a low of 35.2 per 100,000 p-yrs in 2015 and a high of 42.4 per 100,000 p-yrs in 2018, after which the rate decreased to 38.9 per 100,000 p-yrs in 2019. Compared to service members in other race/ ethnicity groups, non-Hispanic blacks had the highest overall rate of exertional rhabdomyolysis in every year except 2018. Overall and annual rates were highest among Marine Corps members, intermediate among those in the Army, and lowest among those in the Air Force and Navy. Most cases of exertional rhabdomyolysis were diagnosed at installations that support basic combat/recruit training or major ground combat units of the Army or the Marine Corps. Medical care providers should consider exertional rhabdomyolysis in the differential diagnosis when service members (particularly recruits) present with muscular pain or swelling, limited range of motion, or the excretion of darkened urine after strenuous physical activity, especially in hot, humid weather.