Conclusions
HPS, CRF
CRF
In this study we successfully recruited 6 to 10-year-old pupils to participate in interventions from the ACTIPROS toolbox and the associated control arm. We were able to demonstrate the feasibility of collecting accelerometer and motor skills data at two timepoints. We also showed that the provision of a toolbox with different interventions for the promotion of PA and CRF based on a comprehensive scoping review and mapped according to the WHO HPS framework was well appreciated by school staff. All intervention classes from a heterogenous sample of local primary schools were able to implement at least one intervention from the ACTIPROS toolbox, and unsuitable interventions were successfully replaced in a timely manner. The data demonstrate that the ACTIPROS toolbox has the potential to positively affect children’s MVPA, but a future full trial is needed to provide reliable evidence. We estimated that for such a trial a sample of 552 children, recruited from 46 classes would be needed to detect an 11 min difference in daily MVPA.