A Preschool Physical Activity Policy in Stockholm: A Pragmatic Cluster RCT

Background

Preschools are promising settings for population-level physical activity promotion, but evidence on the real-world effectiveness of preschool physical activity policies remains limited. We evaluated whether a co-created preschool physical activity policy increased objectively measured physical activity among children in Stockholm, Sweden.

Methods

The Increasing Children’s Physical Activity by Policy study was a pragmatic, single-blinded, cluster-randomized controlled trial conducted in public preschools across all 13 municipal districts of Stockholm. A total of 124 preschools and 3,751 children aged 3–5 years were randomized 1:1 to intervention or usual practice. The intervention included requirements for outdoor time, teacher-led active play, weekly excursions, limited screen use, and encouragement of active transport. Primary outcomes were moderate-to-vigorous physical activity, total physical activity, and step counts during preschool hours, measured by wrist-worn accelerometers at baseline and 6-month follow-up. Analyses used intention-to-treat linear mixed-effects models accounting for clustering.

Results

After 6 months, there were no statistically significant between-group differences in moderate-to-vigorous physical activity, total physical activity, or step counts during preschool hours. Both groups increased physical activity similarly over time. No clinically meaningful differences were observed for adiposity, musculoskeletal fitness, or psychosocial functioning.

Conclusions

In this large pragmatic cluster-randomized trial, a co-created preschool physical activity policy did not increase children’s physical activity beyond usual practice after 6 months. These findings highlight the difficulty of translating policy adoption into measurable behavioural change in real-world preschool settings.

Key messages

• A co-created preschool physical activity policy did not increase children’s accelerometer-measured physical activity after 6 months evaluated by a pragmatic cluster randomised controlled trial.

• It is complex to evaluate effects in real life. Policy-based preschool interventions may need stronger implementation support and longer institutionalization to change behaviour.