Análise do comportamento do conteúdo e da densidade mineral óssea de jovens atletas durante a 1º temporada de treinamento sistematizado no futebol

Abstract

INTRODUCTION: The systematic soccer training is an important stimulus for the process of bone mineralization in young people, but little is known about the process of bone tissue adaptation in adolescents who begin this training during the peak height velocity. (PHV). OBJECTIVE: To monitor and evaluate the behavior of bone health indicators (BMD and BMC) in young athletes, sub-15 football category, during the first training and competition season. METHODS: Participants were 14 athletes [14.8 ± 0.4 years; 61.0 ± 9.6 kg; 171.2 ± 5.5 m; -0.2 (CI = -0.4; 0.5) years for PVC] monitored during 14 weeks of training (3 times per week / 2h day). During this period there were: internal training load (session PSE); the anthropometric measurements for the evaluation of the peak of growth velocity (PHV); bone mineral density (BMD) and bone mineral content (BMC) through DEXA. The monitoring was carried out in three moments: 1) Baseline; 2) the end of the preparation period (PP) and 3) the end of the competitive period (PC). Also, the average intake of calcium through the Food Recall (R24h) and the level of physical activity by accelerometry were investigated. The Student's t-test was used to compare the internal average load between PP and PC periods; The repeated-measures ANOVA followed by the Bonferroni post hoc was used to compare the descriptive variables of the sample, BMC and BMD, during the 3 monitoring moments, using PHV as adjustment covariate. RESULTS: The internal average load of the Periods of Preparation (PP) and Competitive Period (CP) were similar [1493,0 ± 148,5 vs. 1344,7 ± 311,9 u.a., t(16) = 2,109; p = 0,051]. There was an effect of the time adjusted by the PVC on the BM of the leg [F(2, 24) = 10,158; p = 0,001; ƞ2 p = 0,458; poder = 0,973], trunk [F(2, 24) = 5,851; p = 0,009; ƞ2 p = 0,328; poder = 0,827] and body [F(2, 24) = 16,630; p < 0,001; ƞ2 p = 0,581; poder = 0,999], as well as body BMD [F(2, 24) = 5,848; p = 0,009; ƞ2 p = 0,328; poder = 0,827]. The BMC of the leg (mean difference = 25.0 g; p = 0.001) and trunk (mean difference = 23.3 g; p = 0.013) was higher at the 3rd moment (CP) compared to the baseline. The body CMO was higher in the CP compared to the baseline (mean difference = 52.8 g; p = 0.001) and PP (mean difference = 33.0 g; p = 0.003). The BMD of the total body was higher in the PC compared to the baseline (mean difference = 0.17 g / cm2; p <0.001). CONCLUSION: During the training and competition season an increase in BMC and BMD was observed. Thus, the conclusion of the study is that systematic football training, even during the growth spurt process, has had a positive impact on bone health markers.