Diamond T H, Smith R, Goldman A P, Myburgh D P, Bloch J M, Visser F
S Afr Med J. 1983 Jan 8;63(2):37-41.
Serum creatine kinase iso-enzyme (CK-MB) levels were measured in 51 marathon runners before and after a 50 km marathon event. Ninety-five per cent of the runners were found to have pathologically elevated values, i.e. CK-MB concentrations were elevated to the range normally considered indicative of myocardial necrosis. Results indicate that a rise in the CK-MB level is common after marathon running. We therefore believe that cardiac enzymes are an unreliable indicator of myocardial infarction in patients who experience chest pain following strenuous muscular exercise.