Forty Marine Corps recruits were hospitalized at the Naval Hospital, Beaufort, SC, with acute exertional rhabdomyolysis following several days of excessive upper body calisthenics. After an uncomplicated hospital course, they returned to the regular training program and follow-up was continued for one year. Fluctuations of serum creatinine phosphokinase and glutamic oxaloacetic transaminase levels followed the severity of physical stresses encountered. There was no recurrence of rhabdomyolysis, and serum blood urea nitrogen levels, creatinine levels, and creatinine clearance remained within normal limits. Muscle strength was initially reduced in those muscle groups affected but was normal when retested 100 days later. Subjective feelings of persistent muscle weakness in some were not corroborated by exercise testing. Acute exertional rhabdomyolysis, of mild to moderate severity, is a self-limited and benign disease when diagnosed and treated accordingly.