Discussion
CRF
RECRUITMENT, CRF
To the best of our knowledge, this is the first study that systematically compiled evidence-based interventions to promote PA and CRF via primary schools into a toolbox and that piloted the feasibility of working with such a toolbox in the school setting. We obtained promising results in terms of recruitment, data collection and general acceptance of working with the ACTIPROS toolbox. A heterogeneous sample of local primary schools that was ranked and selected by a social index could be included. Intervention schools implemented up to three different interventions from the toolbox over the course of one school year. In case of any problems regarding intervention implementation, participating schools were able to successfully switch to another intervention.Furthermore, we found that among the 10 intervention classes, seven out of twelve possible interventions were selected. Thus, schools in our sample had different interests and needs in the field of PA and CRF promotion, which could be met with a selection of different programs. Generally, intervention sites tended to choose smaller and less complex interventions in our feasibility study. While current scientific literature favours so called ‘complex interventions’ that address multiple levels at the same time [