RESUMEN
Abstract Exercise intensity monitoring has been essential for the control and planning of sports training. Thus, the aim of the present study was to assess the chronic physiological demand of soccer players during an annual soccer season using blood biomarkers. Ten professional soccer players (21.2 ± 3.7 years) participated in this study. Blood samples were collected on the day before beginning of preseason (C1); at the end of preseason and beginning of competitive calendar (C2); and at the end of the competitive calendar. Interleukin-6 (IL-6), cortisol, testosterone, testosterone/cortisol ratio, creatine kinase and alpha-actin were evaluated. Statistical analysis was performed by using ANOVA with repeated measures and the post-hoc Tukey's test. Significance level was set at P<0.05. The results showed significant differences in the following situations: testosterone - C1 higher than C2 and C3; cortisol - C3 higher than C2; testosterone/cortisol ratio - C2 higher than C1, and C3 lower than C1 and C2; creatine kinase - C2 and C3 higher than C1; alpha-actin - C3 higher than C1. IL-6 concentrations were not different between C1, C2 and C3. It could be concluded that an annual soccer season imposes high physiological demand for professional players, since relevant changes in blood biomarkers analyzed were observed.
Resumo O monitoramento da intensidade de esforço entre atletas tem se mostrado essencial para o controle e planejamento do treinamento desportivo. Assim, o objetivo do presente estudo foi avaliar por meio de biomarcadores sanguíneos a demanda fisiológica crônica de jogadores de futebol ao longo de uma temporada anual. Dez jogadores profissionais (21,2 ± 3,7 anos) participaram desse estudo. As coletas de sangue foram realizadas no dia anterior ao início da pré-temporada (C1), ao final da pré-temporada e início das competições (C2), e ao final do ano competitivo (C3). Investigou-se as variáveis cortisol, testosterona, relação testosterona/cortisol, creatina quinase, alfa-actina e interleucina 6 (IL-6). Para a análise estatística dos dados utilizou-se ANOVA para medidas repetidas e foi adotado nível de significância de 5%. Os resultados encontrados indicaram diferenças significativas nas seguintes situações: testosterona - C1 maior do que C2 e C3; cortisol - C3 maior do que C2; relação testosterona/cortisol - C2 maior do que C1, e C3 menor do que C1 e C2; creatina quinase - C2 e C3 maior do que C1; alfa-actina - C3 maior do que C1. As concentrações de IL-6 em C1, C2 e C3 não demonstraram diferenças significativas. Pode-se concluir que uma temporada anual de futebol impõe elevada demanda fisiológica entre jogadores profissionais, uma vez que foram observadas alterações relevantes sobre os biomarcadores sanguíneos analisados.
RESUMEN
The purpose of the present study was to investigate the relationships between the peak running velocity, and aerobic and anaerobic capacity in incremental running in pre- and post-competitive season using eight long distance runners. Measurements were peak running velocity, VO<SUB>2max</SUB>, running velocity and VO<SUB>2</SUB> at respiratory exchange ratio (RER) 1.0, and blood lactate after exhaustion in the incremental running test. Correlation analysis revealed that pre-season velocity at RER 1.0 and post-season blood lactate were both related to peak running velocity. Furthermore, change in peak running velocity was related to change in blood lactate between pre-and post-season. These results suggest that factors that probably influenced running performance change from aerobic capacity in the pre-season to anaerobic capacity in the post-season, and that running performance during the competitive season may be highly dependent upon anaerobic capacity.