Serum cardiac markers are inversely associated with VO(2)max of amateur athletes in response to endurance training adaptations

BACKGROUND: The influence of endurance training intensity and adaptation on serum cardiac markers is poorly understood and controversial; however, no enough data observed the association of serum cardiac markers with VO(2)max. Therefore, we aimed to investigate whether serum cardiac markers are associated with maximum oxygen consumption (VO(2)max) in response to 12-week endurance training on amateur athletes. METHODS: 15 apparently healthy male amateur athletes with 19.47 ± 1.30 years of age were recruited and participated in endurance training with 70%–80% maximal heart rate intensity for 35 min per session for the first week and 2 min increments each week from the second to the last week for a period of 12 weeks. VO(2)max and serum cardiac markers (lactate dehydrogenase [LDH], creatine kinase myocardial band (CK-MB) and cardiac troponin I [CTnI]) were assessed at the beginning of the training and after 12-week endurance training. RESULTS: The result of CTnI indicated significantly (p < 0.01) and inversely (r = − 0.466) correlated with VO(2)max and CK-MB indicated significantly (p < 0.01) and inversely associated with VO(2)max (r = − 0.536) with moderate relationship. However, we did not find a significant association on LDH (p > 0.05) with VO(2)max in response to endurance training adaptation. CONCLUSION: Our finding confirms our hypothesis that serum cardiac markers are inversely associated with estimated VO(2)max in response to endurance training adaptation.