A study on the effects of severe repetitive exercise on serum myoglobin, creatine kinase, transaminases and lactate dehydrogenase.

Two groups of young men taking part in a 24-day training course involving increasingly severe exercise were studied. Serum myoglobin, creatine kinase, creatine kinase-MB, transaminases, lactate dehydrogenase, urea, creatinine, calcium and uric acid were estimated at intervals. During the first few days, increases in myoglobin and muscle enzymes correlated with the severity of the preceding exercise. Increases in myoglobin and muscle enzymes after the final most severe exercising were less than with the initial exercising, demonstrating the effect of physical training. The changes in myoglobin and the muscle enzymes correlated closely. Elevated myoglobin levels persisted for over 24 hours. There was no consistent correlation between changes in myoglobin and uric acid, both of which have been considered responsible for the renal failure which may occur with rhabdomyolysis.