Study design and recruitment
CRF
CRF
This study was a two-arm cluster-randomized feasibility trial, stratified by district and matched for area-level deprivation, with pre-/post measurements of habitual PA, CRF and motor skills conducted at ten primary schools, with schools as the unit of allocation. Trial design, analysis and interpretation was guided by the extension to randomised pilot and feasibility trials of the Consolidated Standards of Reporting Trials (CONSORT) 2010 statement and the ‘CONSORT 2010 checklist of information to include when reporting a pilot or feasibility trial [see Additional file 
Selection process of participating intervention and control schools
The implementation of the random allocation sequence was generated by MB by using MS Excel 2013 random number generator (Mersenne-Twister algorithm). Given the procedure as described in Fig. 