‘WeekendGo!’ A digital health intervention for promoting children’s physical activity in the family environment: a cluster randomised controlled trial protocol

Insufficient physical activity (PA) among children has become a major global public health concern. The family environment plays a crucial role in shaping children's weekend PA, yet evidence-based interventions in this context remain scarce This study will conduct a three-arm cluster randomised controlled trial, 'WeekendGo!' guided by an integrated theoretical framework that encompasses the Social Cognitive Theory, Health Action Process Approach and Family Functioning Theory, aimed at promoting children's weekend PA. Approximately 555 children and their parents will be recruited and randomised into three groups: a staged intervention group (intervention I), a general intervention group (intervention II) and a control group, for 12 months. The primary outcome will be the children's weekend moderate-to-vigorous PA. Secondary outcomes will include children's cognitive factors such as self-efficacy, perceived barriers and resources, motivation and behavioural intention. Generalised linear mixed-effects models will be used for analysis, adhering to the intention-to-treat principle, with missing data handled through multiple imputation. Trial registration number: ChiCTR2500095942.