Exploring the effect of a school-based cluster-randomised controlled trial to increase the scheduling of physical activity for primary school students on teachers' physical activity

Background To determine if a school-based physical activity (PA) intervention that supported primary school teachers to schedule PA during school hours impacted their own PA. Methods A 2x2 factorial group cluster-randomised controlled trial was undertaken in 12 Australian primary schools. The nine-month intervention supported classroom teachers to increase scheduled weekly PA for their class via physical education, sport, Energisers and integrated lessons. Teachers' PA (n = 76) was measured at follow-up only using accelerometers (Actigraph GT3X or GT9X). Linear mixed models were used to estimate between-group differences in teachers' mean minutes of sedentary, light, moderate-to-vigorous-intensity physical activity (MVPA) across the school day and during class-time. Results At follow-up, there were non-significant between-group differences favouring intervention teachers, compared to controls, for light PA (4.9 minutes, 95% CI: -6.3, 16.0; P = .33) and MVPA (0.4 minutes, 95% CI: -10.9, 11.6; P = .94) across the school day; although not favouring the intervention for sedentary behaviour (5.1 minutes, 95% CI: -11.4, 21.7; P = .48). Similar patterns were seen during class-time for light PA and sedentary time, but not for MVPA. Conclusions Supporting teachers with the scheduling of PA for their class may impact on their own PA. Fully powered studies are needed to better understand the impact of the intervention on teachers' PA. Trial registration Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12616001228471 ().