Myoglobinemia and endurance exercise: A study of twenty-five participants in a triathlon competition

Abstract

Twenty-five athletes competing in a triathlon, an endur ance competition, were studied to determine the rela tionship of sustained muscle exertion with myoglobin emia and clinical rhabdomyolysis. Of 24 athletes who completed the event, each individual demonstrated a dramatic rise and fall in serum myoglobin over a 24 hour period, with an average peak level of 842 ng/ml. While all subjects exhibited symptoms of myalgia after exertion, none required hospitalization. A significant correlation was demonstrated with average serum my oglobin and finishing time ( P < 0.0125) and postexer cise temperature ( P < 0.05). Appropriate training of individuals, whether athletes or military recruits, ap pears to be an important factor in reducing myoglobin emia. Exercise-induced myoglobinemia appears to be dependent on intensity of athletic performance, meas ured as a function of time, distance, and activity per formed. The athletes who finished first had the highest levels of myoglobinemia.