Moderate-to-Vigorous Physical Activity and Sedentary Behavior: Independent Associations With Body Composition Variables in Brazilian Children

Abstract:

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