OLYMPIC-S: Outcomes of a Life-stYle Multicomponent Physical-activity Intervention in Children at School

OLYMPIC-S is a cluster randomized controlled trial evaluating a four-month school-based intervention designed to increase moderate-to-vigorous physical activity and promote healthy habits among children in the fourth, fifth and sixth grades of primary school. Fifteen schools and approximately 1,200 children will participate. Schools will be randomized to the Olympic School intervention or to a control group continuing usual school activities. Intervention schools will introduce 15 minutes of physical activity during each school day. Teachers may choose between outdoor walking or running activities based on The Daily Mile or structured movement video sessions from the Born to Move programme. A gamified web platform will record the activity performed, display each school's collective progress through an Olympic journey, unlock educational content and reinforce messages related to physical activity, healthy eating, hydration and sleep. Outcomes will be assessed at baseline and immediately after the four-month intervention. The primary outcome is daily moderate-to-vigorous physical activity measured using the PAU-7S questionnaire. Secondary outcomes include dietary habits, fruit and water consumption, sleep, emotional well-being, health-related quality of life, adherence, platform use, feasibility and acceptability. Post-intervention focus groups with children and teachers will complement the quantitative evaluation.