Inter-individual variability in children's physical growth and body composition: Findings of longitudinal ELOS-Pré study.

BACKGROUND: Children's physical growth (PG) and body composition (BC) can be influenced by birth weight and type of delivery. AIM: To longitudinally analyze the dynamics of PG and BC of children from 5 to 9 years; to investigate the inter-individual differences according to age, sex, BW, and type of delivery across the following years of the study. SUBJECTS AND METHODS: A total of 1236 children (597 boys) were evaluated at 5-years of age and followed annually until 9-years. PG and BC measurements were evaluated. Multilevel modeling was used. RESULTS: Annual increments were observed (p < .001). Girls presented lower height and fat-free-mass but higher %BF (p < .001). Distinct trajectories between the sexes were observed for height (p < .001). Low-birth-weight children presented lower height, body mass, and fat-free-mass (p < .001), but the interaction between velocity of growth and BC was significant only in height (p < .05). Children born by had lower height, body mass, and %BF, and gained less body mass per year than those born by vaginal delivery (p < .05). Significant inter-individual differences were observed at 5-years of age and in their trajectories, except for fat-free-mass (p < .01). CONCLUSION: There are differences in the dynamics of PG and BC, low-birth-weight and type of delivery influence the dynamics of PG during this interval of ages.

Cardiorespiratory fitness in adolescents with obesity: a 6-month follow-up study / Aptidão Cardiorrespiratória em Adolescentes com obesidade: um estudo de seguimento de 6 meses

The aim of this study was to investigate whether the effects of a multidisciplinary intervention on cardiorespiratory fitness are maintained after 6-month follow-up in adolescents with obesity. One-hundred and seven adolescents with obe-sity were intentionally allocated in two groups: experimental or control. Adolescents in experimental group underwent a multidisciplinary intervention (supervised aerobic exercise, psychological, nutritional, and clinical counseling). Cardiorespiratory fitness (direct gas analysis), body composition (dual-energy-DXA), anthropometry and blood lipids were measured before intervention (baseline), at the end of the 24-week intervention (post-intervention) and six months after the end of the intervention (follow-up). Cardiorespiratory fitness reduced in control group with no changes in experimental group, and these differences were maintained in the follow-up assessment (control group: 24.2±4.4 ml.kg-1.min-1to 22.6±4.9 ml.kg-1.min-1; follow-up: 22.6±4.9 ml.kg-1.min-1 vs. experimental group: 28.0±4.0 ml.kg-1.min-1 to 29.7±4.0 ml.kg-1.min-1; follow-up: 28.9±5.7 ml.kg-1.min-1). Reductions in z-score body mass index (BMI) and increases HDL-C af-ter multidisciplinary intervention were maintained after a 6-month follow-up. In conclusion, the benefits of a multidisciplinary intervention on cardiorespiratory fitness, BMI and blood lipids are maintained after a 6-month follow-up. These findings indicate that multidisciplinary interventions produce long-term health consequences on cardiorespiratory fitness. Reinforcing the importance of lifestyle changes as a therapeutic approach for the treatment of obesity in adolescents.

O objetivo do presente estudo foi investigar se os efeitos da intervenção multidisciplinar sobre a aptidão cardiorrespiratória são mantidos após um período de segmento de 6 meses em adolescentes com obesidade. Cento e sete adolescentes com obesidade foram intencionalmente alocados em dois grupos: experimental e controle. Os adolescentes do grupo experimental foram submetidos a intervenção multidisciplinar composta por acompanhamento psicológico, nutricional, clínico e treinamento aeróbio. Aptidão cardiorrespiratória (análise de gases), composição corporal (DEXA), antropometria e perfil lipídico foram avaliados no momento basal, após 24 semanas de intervenção e 6 meses após (follow up). A aptidão cardiorrespiratória reduziu no grupo controle sem alterações no grupo experimental, mesmo após o período de 6 meses (controle: 24,2±4,4 ml.kg-1.min-1 para 22,6±4,9 ml.kg-1.min-1; follow-up: 22,6±4,9 ml.kg-1.min-1 vs. grupo experimental: 28,0±4,0 ml.kg-1.min-1 para 29.7±4.0 ml.kg-1.min-1; follow-up: 28,9±5,7 ml.kg-1.min-1). Redução no escore-z do índice de massa corporal (Z-IMC) e elevação do HDL-c verificadas após 24 semanas, foram mantidas após o período de segmento. Os resultados indicam que os efeitos da intervenção multidisciplinar são mantidos após 6 meses de seguimento. Estes achados sugerem que intervenções multidisciplinares podem produzir alterações benéficas de longo prazo na capacidade cardiorrespiratória.

The role played by gender and age on poor sleep quality among institutionalized adolescents.

PURPOSE: The aim of this study was to analyze the prevalence and association between sleep quality with gender and age and to examine the relation between age and the components of the PSQI in institutionalized adolescents. METHODS: High school internal students of both genders, aged between 14 and 19 years old, were analyzed. After a full clinical evaluation, the Pittsburg Sleep Quality Index Score was obtained from all participants. RESULTS: We studied 210 participants [male: 15. 7 ± 1.2 years; BMI: 21.7 ± 2.6 kg/m2; female: 15.7 ± 1. 2 years; BMI: 21.9 ± 4.5 kg/m2]. Poor sleep quality was present in 137 (65.3%) participants and was predominant among girls than boys (PSQI = 76.3 vs 55.8%; p < 0.001), respectively. There were positive correlations between PSQI components with age in boys (sleep latency: R = 0.23; p = 0.02; sleep duration: R = 0.28; p < 0.01 and overall sleep quality: R = 0.21; p = 0.03), but not among girls. CONCLUSION: Institutionalized girls have worse sleep quality than boys and positive correlations between sleep quality components with age were only present among boys.

Estimate of propulsive force in front crawl swimming in young athletes.

BACKGROUND: Improvement in swimming performance involves the dynamic alignment of the body in liquid, technical skill, anthropometric characteristics of athletes, and the ability to develop propulsive force. The aim of this study was to assess the relationships between the propulsive force during swimming and arm muscle area (AMA) and propose an equation to estimate the propulsive force in young swimmers by measuring their AMA. METHODS: Study participants were 28 male swimmers (14 ± 1.28 years) registered in the Brazilian Federation of Aquatic Sports. Their AMA was estimated by anthropometry and skinfold measurement, and the propulsive force of their arm (PFA) was assessed by the tied swimming test. The Durbin-Watson (DW) test was used to verify residual independence between variables (PFA and AMA). A Pearson correlation investigated potential associations between the variables and then a linear regression analysis was established. The Bland-Altman method was used to compare the values found between PFA and propulsive force-estimated (PFE). A paired Student's t-test was used to analyze the difference in PFE with and without the constant and the coefficient of variation (CV) to estimate the magnitude of a real change between these forces. RESULTS: There was a significant positive correlation between the variables AMA and PFA (r = 0.68, P < 0.001). The linear regression showed a value of R(2) = 0.470. There were no significant differences when comparing PFA and PFE (95% confidence interval: -8.903 to 9.560 kgf). To verify if there was a correlation between these variables, a new linear regression analysis found a value of R(2) = 0.668, which confirms an equivalence between PFA and PFE, as CV showed 4% of magnitude. CONCLUSION: The results of this study suggest the existence of a relationship between levels of PFA and muscle mass, however, this relationship becomes more evident the longer the AMA, which allows the development of an equation to estimate the propulsive force of young swimmers.