Family and home influences on children's after-school and weekend physical activity

Background: Family- and home-related factors have been shown to be associated with children's physical activity (PA), but may be time-dependent. Here we investigate whether family- and home-related correlates of children's PA are different for the after-school period on weekdays than for the weekend. Methods: Data on 21 family- and home-related variables and objectively measured PA (Actigraph GT1M) were available from 1608 Year 5 children (9-10 years old) from 92 schools in Norfolk participating in the SPEEDY (Sport, Physical activity and Eating behaviour: Environmental Determinants in Young people) study. Multi-level multiple linear regression was used to quantify cross-sectional associations between the family/home variables and average min per day of moderate-to-vigorous PA (MVPA, epsilon 2000 counts/min) after school on weekdays and at the weekend. Models were additionally adjusted for age, sex, BMI z-score and registered accelerometer wear time. Results: After-school MVPA was associated with parent education (ss: -1.1; 95% CI -2.0 to -0.2), being allowed to play out in the neighbourhood (ss: 1.3; 0.7-1.8), restrictions on walking/cycling to friends' houses (ss: -1.1; -1.6 to -0.7), restrictions on sedentary behaviour (ss: -0.3; -0.5 to -0.02) and family social support (ss: 1.0; 0.7-1.3). Weekend MVPA was associated with number of siblings (ss: 2.6; 0.5-4.8), family encouragement (ss: 1.1; 0.2-2.0) and family social support (ss: 1.5; 0.5-2.5). Conclusion: Family social support is positively associated with children's out-of-school PA both at weekdays and in weekends. However, rules and restrictions appear to be important only on weekdays. The results of this study merit consideration when identifying appropriate timing of PA-promotion strategies.