Statistical analyses
Data was double-entered and validated using EpiData (version 3.1), and EvaSys (version 7.1) was used to appraise questionnaire data. Continuous outcomes were described with medians and 95% confidence intervals (CI), while categorical variables were presented as frequencies and 95% CI. Since missing data differed by outcome, we reported sample size for each analysis separately. We applied a series of separate linear mixed models to evaluate the short-term intervention effect on PA and health outcomes by risk group using classes as random effects. Model for zBMI-for-age was controlled for baseline levels and SES. Models for MAP, HbA1c and TC to HDL ratio were controlled for baseline levels, age, sex, and SES. Total and school MVPA were controlled for baseline levels, age, sex, SES, and wear-time. Post-hoc analyses included studying the effect of the intervention on PA levels by sex. To assess the long-term development of cardiovascular risk factors in the subsample of at-risk children, we performed pair-wise Wilcoxon signed-rank tests for within-subject variations between baseline, post-intervention and follow-up. Size effect r was calculated as the absolute 