ABSTRACT
Objectives: To compare the effects of self-selected and predetermined intensity on sleep quality and duration, daytime sleepiness, and sleep efficiency of adolescents with obesity after 12 weeks of aerobic training. Material and Methods: Thirty-seven adolescents (12 girls), 13-18 years old, with obesity (BMI = 95th) were randomized into a predetermined intensity group (PIG), exercise intensity around 60-70% of heart rate reserve; or self-selected intensity group (SIG), the adolescents chose the speed/intensity at the beginning of each session and were able to change it every 5 minutes. The Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) were used to assess sleep outcomes. Results: No differences were observed for PSQI [0.00 ± 2.00 vs 1.38 ± 2.7; p=0.195; d=0.60 (moderate effect)], sleep duration [-0.95 ± 1.2 vs -0.35 ± 1.6; p=0.358; d=0.41 (small effect)], ESS [(2.10 ± 3.9 vs 1.15 ± 4.5; p=0.195; d=0.23 (small effect)], and sleep efficiency [(81.5 ± 24.0 vs 79.4 ± 17.0; p=0.8.14; d=0.10 (trivial effect)] for the PIG and SIG groups, respectively. Conclusion: Aerobic training at a self- selected or predetermined intensity does not modulate sleep quality, sleep duration and efficiency, and daytime sleepiness, independent of intensity.
ABSTRACT
Abstract The purpose of this present study was to develop and validate a prediction equation for body composition assessment using anthropometric measures of elderly women. This is cross-sectional correlational study with 243 older women ± 64.5 years old and body mass index (BMI) ± 28.70 kg/m². For the development of the equation it was utilized the method of hold-out sample validation. The participants were randomly divided into equation development group (96 elderly women) and a group for validation (147 elderly women). Total body mass, height, waist and hip circumferences, ratio waist-hip ratio and BMI were measured. The whole-body dual-energy X-ray absorptiometry (DXA) assessed body composition (percentage of body fat, fat mass, and fat-free mass). The equations were developed using multiple linear regression, with validation by the stepwise method; the comparison of the equations was analyzed by the paired Student's t test and the analysis of residual scores by the method of Blant and Altman. The New Equation presents a strong correlation (R = 0.83) and (R² = 0.69), and a standard error of estimation equals to 3.21% for percentage body fat prediction. The mean difference between the estimations of percentage body fat from DXA and the New Equation was 0.11% (t(0,180); P = 0.850). Therefore, the New Equation had an accuracy of 93.5% and a total error of 1.8%. The body fat estimation in older women using this New Equation based on BMI and age is valid and accurate.
Resumo O objetivo do presente estudo foi desenvolver e validar uma equação de predição para avaliação da composição corporal utilizando-se medidas antropométricas de idosas. Este é um estudo transversal e correlacional com 243 idosas ± 64.5 anos de idade e índice de massa corporal (IMC) ± 28.70 kg/m². Para o desenvolvimento da equação utilizou-se o método de validação hold-out. As participantes foram divididas aleatoriamente em um grupo para desenvolvimento da equação (96 idosas) e um grupo para validação da equação (147 idosas). Massa corporal total, estatura, circunferências da cintura e quadril, relação cintura-quadril e IMC foram mensurados. A absorciometria por raios-X com dupla energia (DXA) para todo corpo foi utilizada para avaliação da composição corporal (percentual de gordura, massa gorda e massa livre de gordura). As equações foram desenvolvidas utilizando a regressão linear múltipla, com validação pelo método stepwise; a comparação das equações foi realizada pelo Teste T para amostras pareadas e análise dos escores residuais por meio do método de Bland e Waltman. A Nova Equação apresentou uma forte correlação (R = 0.83) e (R2 = 0.69), e uma estimativa de erro padrão de 3.21% para predição do percentual de gordura. A diferença média entre as estimativas de percentual de gordura pelo DXA e Nova Equação foi de 0.11% (t(0,180); P = 0.850). Assim, a Nova Equação teve uma precisão de 93.5% e um erro total de 1.8%. A estimativa do percentual de gordura em idosas usando a Nova Equação baseada no IMC e idade são válidos e precisos.
