RESUMO
Moderate to vigorous physical activity plays a recognized osteogenic effect on bone. Moreover, sedentary time, and fat accumulation are unfavorable to bone health. Our study aimed (1) to examine changes in body composition, bone tissue, physical activity, and sedentary time; and (2) to explore whether changes in physical activity intensities and in sedentary time are associated with changes in bone outcomes after a school-based interdisciplinary intervention program. A total of 53 over-weight/obese students (10.6 ± 3.5 year-olds; 26 girls) participated in physical activity classes. Bone area, bone mass, and bone mineral density z-score, body composition (fat mass, fat lean mass), phys-ical activity, sedentary time and potential confounders (vitamin D and maturational status) were assessed at baseline, and 8 months later. General Linear Models were carried out and significance level was set at 5%. Changes in moderate to vigorous physical activity were positively correlated with changes in all bone mass indicators. We observed a significant overall effect of the intervention on bone mineral density z-score changes, however after adjustments for changes in sedentary time and moderate to vigorous physical activity, no effect was observed. Finally, variations in sedentary time and in moderate to vigorous physical activity play an important role in bone mass density in those participants of the interdisciplinary program
A atividade física moderada-vigorosa tem efeito osteogênico reconhecido no osso. Além disso, o tempo sedentário e o acúmulo de gordura são desfavoráveis à saúde óssea. Este estudo objetivou: (1) examinar mudanças na composição corporal, tecido ósseo, atividade física e tempo sedentário; e (2) explorar se as mudanças nas intensidades de atividade física e no tempo sedentário estão associadas a mudanças nos resultados ósseos após um programa de intervenção interdisciplinar de base escolar. 53 estudantes com sobrepeso/obesidade (10,6 ± 3,5 anos; 26 meninas) participaram de aulas com atividade física. Área óssea, massa óssea e escore z de densidade mineral óssea, composição corporal (massa gorda, massa magra de gordura), atividade física, tempo sedentário e potenciais confundidores (vitamina D e status maturacional) foram avaliados no início e após 8 meses. Modelos Lineares Generalizados foram realizados e o nível de significância foi estabelecido em 5%. Alterações na atividade física moderada-vigorosa foram positivamente correlacionadas com as mu-danças em todos os indicadores de massa óssea. Observou-se um efeito geral significativo da intervenção nas alterações do escore z de densidade mineral óssea, entretanto, após ajustes para mudanças no tempo sedentário e atividade física moderada-vigorosa, nenhum efeito foi observado. Por fim, variações no tempo sedentário e na atividade física moderada a vigorosa desempenham importante papel na densidade da massa óssea nos participantes do programa interdisciplinar
Assuntos
Humanos , Masculino , Feminino , Educação Física e Treinamento , Osso e Ossos , Comportamento Sedentário , Atividade MotoraRESUMO
This study evaluated the effect of a multi-component intervention on motor performance (MP) and metabolic risk markers (MRM) in overweight/obese youth. A secondary aim was to examine whether changes in MP are associated to changes in MRM. A 3-month multi-component intervention was performed, consisting of physical exercise sessions (twice/week;1h), nutritional education sessions (once/month), and parental support (twice/week). The sample included 35 volunteers (7-13 y.o), allocated to intervention (INT, n = 17) and control (CONT, n = 18) group. Variables were measured pre (T0) and post intervention (T1). Fasting blood samples were analyzed for MRM. MP tests included the measurement of health related physical fitness components and motor coordination performance (KTK battery). To assess food intake, a 24-hour recall diary was used. GLM-ANCOVA was performed. Standardized scores were calculated for the outcome variables, and multilinear regressions were applied to analyze associations between the key variables. INT group showed improvements in MP, glycolytic and hepatic profiles. After adjustments for MVPA, SB, total intake and maturational stage, negative associations between %ΔMP and %Δglycolytic (ß = -.424; 95%CI:-0.343:-0.022), and %Δhepatic scores (ß = -.382 95%CI:-0.001:-0.009) were observed. The intervention produced a moderate-to-high effect on the MP and some MRM. Changes in MP were inversely associated with changes in glycolytic and hepatic markers.