The growing interest of children and adolescents in competitive sports demands a higher concern with suitable training prescription to this specific population. The knowledge of the impact of the competitive physical training intensity over the young population's health is still scarce in the literature. Thus, the aim of this study was to examine acute responses in blood lactate (Lac) and creatine phosphokinase (CPK) concentration after a physical training session with young athletes trained in different sports modalities. Forty-three male adolescents (aged 9-17 years) were divided in three groups: swimmers, tennis players, and indoor soccer players. There were no changes in rules or procedures before or after the practice session. Diet and activity (no exercise) were standardized during the twenty-four hours before the evaluation. Venous blood samples (5 mL) were collected from the antecubital vein immediately before and after the training session. The bone age was obtained through the Greulich & Pyle method and was analyzed for skeleton maturity grading. Statistical analysis included Kruskal-Wallis variance analysis and Mann-Whitney U test (alpha was set at 0.05). Both Lac and CPK were higher post-session than pre-session in all sports studied. Age appeared to influence Lac and CPK concentration. The age group between nine and eleven years old had lower values compared to the older group, both pre- and post-session. The increases in CPK and Lac with exercise are similar to the findings previously reported in the literature. Moreover, CPK and Lac are higher with older chronological age. Thus, it is possible to demonstrate that Lac and CPK have a positive correlation to bone maturation and chronological age.
Physical practice; Adolescents; Lactate and creatine phosphokinase
