Correlates of children's compliance with moderate-to-vigorous physical activity recommendations: a multilevel analysis.

This study aimed to investigate the association between individual and school characteristics associated with the number of school days children comply with moderate-to-vigorous physical activity (MVPA) recommendations. Sample comprises 612 Portuguese children, aged 9-11 years, from 23 schools. Time spent in MVPA was measured by accelerometry, while individual-level correlates were obtained by anthropometry and questionnaires. School-level variables were collected by questionnaire, and accelerometer wear time and season were also considered. Maximum likelihood estimates of model parameters were obtained via a multilevel analysis with children as level-1, and school as level-2. Children who spent more time in sedentary activities and girls were less likely to comply with MVPA/daily. More mature children and those who use active transportation to school were more likely to attain the PA recommendation. Furthermore, greater accelerometer wear time and spring season increased the chance to achieve the recommended MVPA. In terms of school-level correlates, a greater number of available facilities was negatively associated with children MVPA compliance. Given the set of variables, our results showed that individual characteristics seem to be more relevant for children's compliance rates with PA/day than school context variables, which should be taken into account in the implementation of school policies and practices.

Body mass index, cardiorespiratory fitness and cardiometabolic risk factors in youth from Portugal and Mozambique.

OBJECTIVES: The objectives of this study are to examine differences in cardiometabolic risk indicators, as well as their prevalences, in Portuguese and Mozambican youth, and to investigate the associations between weight status and cardiorespiratory fitness levels with cardiometabolic risk. METHODS: The sample comprises 721 adolescents (323 Mozambican and 398 Portuguese), aged 10-15 years. Anthropometry (height, sitting height, weight and waist circumference), blood pressure, serum-fasting triglycerides, high-density lipoprotein cholesterol and glucose, and cardiorespiratory fitness were measured. Maturity offset was estimated and a cardiometabolic risk score adjusted for sex, age and biological maturity was computed. Adolescents were classified as normal weight and overweight/obese as well as fit or unfit (cardiorespiratory fitness). RESULTS: Portuguese youth have better cardiometabolic and cardiorespiratory fitness profiles. About 32% and 30% of Portuguese boys and girls, respectively, are overweight/obese; in Mozambicans, these prevalences are 7.5% for boys and 21% for girls; in addition, 81.6% of Portuguese boys and 77.7% of Portuguese girls were classified as cardiorespiratory fit, against 54% and 44.4% of Mozambican boys and girls, respectively. No statistically significant differences (P>0.05) were found between Mozambicans and Portuguese for the cluster of three or more cardiometabolic risk indicators. A positive relationship (P<0.001) was found between weight status and cardiometabolic risk in adolescents from both countries; however, a negative association (P<0.001) between cardiorespiratory fitness and cardiometabolic risk was only found among Portuguese youth. CONCLUSIONS: Portuguese and Mozambican youth differ in their cardiometabolic risk profiles, body weight and cardiorespiratory fitness, favoring Portuguese. Overweight/obesity and low cardiorespiratory fitness levels are related to a worse cardiometabolic risk profile, being relevant to design public health intervention strategies to reduce excess weight and increase cardiorespiratory fitness.