Preliminary findings of Active Classrooms: An intervention to increase physical activity levels of primary school children during class time

•Teaching active academic lessons can improve physical activity levels of students.•Two active lessons per day accumulated 13% of the recommended daily MVPA.•Enjoyment was the dominant theme among participating students.•Teaching and learning were enhanced resulting in high teacher satisfaction.

This study evaluates the effects of a behaviour change intervention, which encourages the integration of physical activity into the teaching of academic lessons, on physical activity levels of students. The main outcome is mean minutes of moderate-to-vigorous physical activity (MVPA) daily generated during the intervention lessons. Teacher's perceptions and students' enjoyment of the programme were also evaluated. Students accumulated a mean of 8 min MVPA during the intervention lessons daily. The teacher and students were very satisfied with the programme. Therefore, changing teacher behaviour towards using physically active teaching methods is a promising way of increasing children's physical activity levels.