Influences on Children's Weekday and Weekend Day Physical Activity: The Change! Project

Objectives To investigate the impact of the CHANGE! curriculum-based intervention across time on children’s weekday and weekend day physical activity (PA) levels and to report effect of covariates on the outcome measures.

Methods Twelve primary schools were randomised to an Intervention (N = 6) or Control condition. Baseline, 20-week post-intervention and 10-week follow-up measures of PA (7-day accelerometry), cardiorespiratory fitness (CRF) and anthropometric measures were completed. Outcome measures were total physical activity (TPA; counts·min^-1), minutes per weekday and weekend day spent being sedentary (SED), and in moderate (MPA), vigorous (VPA), and moderate-to-vigorous physical activity (MVPA). Multilevel modelling was used to assess the effect of the intervention on the outcome variables, as well as the influence of school level (temperature, rainfall, playground area per child, and number of children on roll) and child level (sex, maturation, weight status, accelerometer wear time, CRF, and socioeconomic status (SES)) covariates.

Results There was a significant intervention effect for weekday TPA with children in the Intervention group recording 88.71 cpm more than Control children (p=0.02). The Intervention group engaged in more weekday SED, MPA, VPA, and MVPA, and more bouts, for a longer duration. At weekends Intervention children accrued more SED and VPA mins than Control children, and less TPA, MPA, and MVPA. Boys did significantly more MPA (9.55) and MVPA (13.95) on weekdays and engaged in 5.49 and 2.69 mins MPA and VPA, respectively, during school hours (p<0.01). Weekday PA was significantly influenced by maturation, CRF and playground area per child (p<0.05). Specifically, school-time MVPA mins were predicted by number of children on roll (0.02), temperature (1.19) and maturity offset (7.57), whereas children in the high BMI group engaged in 1.73 mins less VPA (p<0.05). Out of school weekday PA was influenced by CRF, SES and maturity (p<0.05). High MVPA Intervention children increased weekday bouts and had less SED mins during school hours, whereas low SES Intervention children engaged in more weekday bouts and increased TPA (p<0.05).

Discussion A significant intervention effect was observed for weekday TPA, but Intervention children did less on weekends than those in the control group. This suggests that the intervention may have influenced the Intervention children’s PA behaviours differently on weekdays and at weekends.