Resting and post‐exercise serum biomarkers of cardiac and skeletal muscle damage in adolescent runners

This study examined the response of serum biomarkers of cardiac and skeletal muscle damage at rest and after a routine workout of 21 km run in 12 male adolescent (16.2±0.6 years) long-distance runners. Biomarkers of cardiac troponins (cTnT, cTnI), creatine kinase MB mass (CK-Mbmass) and skeletal muscle creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and hydroxybutyrate dehydrogenase (HBD) damage were assayed at rest, 2, 4 and 24 h post-exercise. At rest, cTnT and cTnI were not detectable; however, CK, CK-MBmass, AST, ALT and HBD were above corresponding clinical cut-off values. Post-exercise significant elevations above rest were observed for all biomarkers, except ALT, 2 and 4 h following the run, and remained elevated in cTnI, CK, CK-MBmass, LDH and AST 24 h post-workout. A significant increase in data points above clinical cut-off values from rest to post-exercise was reported for cTnT, cTnI and CK at 2 and 4 h, and in cTnI and CK 24 h post-exercise. In conclusion, a 21 km run in adolescent runners increased post-exercise biomarkers of cardiac and skeletal muscle damage.