Acute variation of biochemical markers of muscle damage following a 21-km, half-marathon run

OBJECTIVE: Although there is information on biochemical markers of muscle and cardiac damage following strenuous exercise, little is known about the kinetics of these markers in athletes performing sub-maximal exercise. MATERIAL AND METHODS: Fifteen healthy, trained, Caucasian males took part in a 21-km run. Blood samples were collected before the run, immediately after (post), and 3 h, 6 h and 24 h thereafter. Biochemical markers of muscle and cardiac damage were evaluated on the Modular System, employing proprietary reagents. In no case did the concentration of troponin T increase by >0.03 ng/mL. The values of aspartate aminotransferase (AST), creatine kinase (CK), CK MB, lactate dehydrogenase (LDH) and myoglobin increased significantly immediately after the run and remained elevated 24 h thereafter. RESULTS: The number of subjects with values above the upper limit of the relative reference ranges did not vary throughout the study period for AST and LDH, while it increased significantly for CK, CK MB and myoglobin. The major variation over the pre-run value was recorded for myoglobin (3-fold increment), whereas AST and LDH increased 1.1 and 1.3-fold, respectively. CONCLUSIONS: The results suggest the hypothesis that sub-maximal exercise influences the concentration of several biomarkers of muscle damage for up to 24 h with no biochemical signs of myocardial damage.