Biochemical adaptations in middle-distance runners: an assessment of blood and anthropometric parameters

In order to understand the mechanism underlying the physiological adaptation of purely aerobic workout, we investigated the effect of 2 months of training on nine males (17-22 year-old) middle distance running agonistic athletes. Blood sample was collected in the morning to analyze: hematological parameters, lipid profile, liver function enzymes [glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, gamma-glutamyl transferase (γ-GT)] and skeletal and myocardial markers of muscle damage [creatin kinase (CK) and creatin kinase MB (CK-MB)]. Endurance training, as it implies high oxygen consumption, should increase reactive oxygen species, but it has been shown that exercise leads to increased activation of antioxidant defenses. In fact, serum levels of γ-GT enzyme and total CK were not increased. On the other hand, a statistical significant reduction of CKMB has been observed. There were not variations in hematological parameters. As far as the anthropometric value is concerned, after two months of training there was a change in weight (P<0.0001). Finally, any oxidative and biological stress was highlighted in the middle distance runners but, since this is a preliminary study, it would be of interest to replicate the study on a larger sample