Creating Active Schools: investigating sustained implementation and long-term (cost)effectiveness on children’s physical activity in multi-ethnic and socioeconomically challenged communities in Bradford.

Physical inactivity in childhood remains a global public health crisis, with fewer than half of English primary-aged children meeting the recommended 60 minutes of moderate to vigorous physical activity (MVPA) per day. This burden disproportionately affects children from Black, Asian, and socioeconomically disadvantaged backgrounds, contributing to long-term health inequalities and poorer academic outcomes. Despite significant investments into school-based activity initiatives in England, the long-term population-level effects remain unclear due to short-term evaluations and a lack of implementation science approaches. To address this challenge, this study proposes a comprehensive, interdisciplinary evaluation of the Creating Active Schools (CAS) programme, based on a co-designed, whole-school physical activity framework. CAS recognises schools as complex adaptive systems and applies behavioural and implementation science to promote sustainable organisational change, supporting an active school culture. Following initial two-year evidence of increased weekday MVPA and sustained physical activity infrastructure improvements in 16 Bradford schools, which deepened over time, an additional five years of local funding has been secured for CAS implementation, providing an unparalleled opportunity to assess CAS’ long-term implementation and effectiveness. This mixed-method, longitudinal evaluation will assess the 5- and 7-year impact of CAS across five integrated work packages (WPs). WP1 will examine long-term effectiveness using repeated cross-sectional accelerometry and anthropometric data in Years 1–3 students, comparing those at intervention and matched control schools. Primary outcome is weekday MVPA; secondary outcomes include weekly and in-school MVPA, sedentary time, physical activity habits, BMI, well-being, and educational attainment. The health economic analysis of WP2 will model quality-adjusted life years and long-term healthcare costs to assess value for money from a school funder perspective. WP3 will investigate sustained implementation using annual qualitative and quantitative assessments across intervention schools, examining system, organisational, and stakeholder-level factors that enable or hinder implementation. WP4 will integrate implementation and effectiveness data using Contribution Analysis, developing a comprehensive theory of change to understand the differential impact of CAS across subgroups, including by gender, ethnicity, and deprivation. WP5 focuses on knowledge mobilisation, co-producing an open-access implementation toolkit, policy briefs, and multimedia outputs for diverse stakeholders, including policymakers, educators, and families. This project represents the first UK-based long-term evaluation of a large-scale, whole-school physical activity approach embedded in a multi-ethnic, socioeconomically challenged population. Findings will inform national and international policies on school-based health promotion, identify scalable and equitable strategies for sustainable implementation, and support cross-sector decision-making on physical activity investment. Through rigorous evaluation, integrated stakeholder engagement, and translational impact, this study aims to deliver transformative knowledge on addressing childhood inactivity, narrowing health inequalities, and enabling lifelong well-being through systemic educational reform.