IMPORTANCE It is unclear whether, for the same amount of total physical activity, a higher proportion of vigorous physical activity (VPA) to total physical activity is associated with a greater reduction in mortality.OBJECTIVE To examine the association of the proportion of VPA to total physical activity (defined as moderate to vigorous physical activity [MVPA]) with all-cause mortality, cardiovascular disease mortality, and cancer mortality.

BackgroundUpper body subcutaneous fat, estimated by neck circumference (NC), may present greater metabolic risk than visceral fat. The aim of this study was to determine cutoff values for NC in adolescents that identify overweight and obesity, the prevalence of elevated NC, and its association with associated factors.MethodsCross-sectional study with adolescents from public schools in São Paulo. Anthropometric variables, blood pressure and pubertal stage were collected. Cutoff values for NC were determined by Receiver Operating Characteristic curves. A binary logistic regression was used to determine relationships between NC and associated factors.ResultsAmong 1668 adolescents studied, 54.92% were female. The cutoff values of NC in girls and boys that identified overweight were 31.25 and 34.25 cm, and obesity, 32.65 and 37.95 cm, respectively, and the prevalence of adolescents with high NC was 32.63% in females and 37.63% among males. NC for overweight was observed that there was an association with sex, weight, body mass index, arm, waist and thigh circumferences, pubertal stages and body fat percent (BF%). NC for obesity was found association with gender, weight, arm and thigh circumferences, and BF% (p < 0.001).ConclusionIt was concluded that there is high prevalence of elevated NC and higher risks for this outcome considering overweight and obesity, sex, weight, arm and thigh circumferences, BF%, besides being an easy and simple measure for use in clinical practice.

Several factors were identified as correlates of MVPA in Brazilian children; however, only travel mode to school was common for both boys and girls.

This study aimed to analyze the independent associations of accelerometer-determined sedentary behavior, physical activity, and steps/day with body composition variables in Brazilian children. 485 children wore accelerometers for 7 days. Variables included time in sedentary behavior and different physical activity intensities (light, moderate, vigorous, or moderate-to-vigorous) and steps/day. Body fat percentage was measured using a bioelectrical impedance scale, and BMI was calculated. Children spent 55.7% of the awake portion of the day in sedentary behavior, 37.6% in light physical activity, 4.6% in moderate physical activity, and 1.9% in vigorous physical activity. Moderate-to-vigorous physical activity and steps/day were negatively associated with body composition (BMI and body fat percentage) variables, independent of sex and sedentary behavior. Beta values were higher for vigorous physical activity than moderate physical activity. Vigorous physical activity was negatively associated with BMI (β-.1425) and body fat percentage (β-.3082; p < .0001). In boys, there were significant negative associations between moderate, vigorous, and moderate-to-vigorous physical activity and steps/day with body composition, and in girls, there was only a negative association with vigorous physical activity, independent of sedentary behavior. Moderate-to-vigorous physical activity and steps/day (in boys), but especially vigorous physical activity (in boys and girls), are associated with body composition, independent of sedentary behavior. Sedentary behavior was not related with any of the body composition variables once adjusted for moderate-to-vigorous physical activity.