B4B Evolution Type II Hybrid Effectiveness-Implementation Trial

Break4Brain Evolution is a school-based programme designed to help teachers incorporate brief, safe and inclusive movement activities into normal classroom routines. The study aims to examine both how the programme is adopted and delivered in real-world schools and whether it improves students' physical activity, attention, executive functions and academic achievement. This is a type II hybrid implementation-effectiveness study with two complementary components. The implementation component will examine the scale-up of Break4Brain Evolution across at least 50 preschool, primary and secondary schools in the Balearic Islands and mainland Spain. Information from school leaders, teachers and students will be used to assess programme reach, adoption, acceptability, feasibility, appropriateness, fidelity, adaptations and maintenance. The effectiveness component is an embedded cluster-randomized controlled trial conducted in six primary schools in Mallorca. Schools will be randomly allocated to either the Break4Brain Evolution programme or usual school practice, with three schools in each group. Two classrooms from each school, one grade 5 and one grade 6 classroom, will participate, resulting in an estimated sample of 300 students. Baseline assessments will be conducted in September 2026. Schools allocated to the intervention group will begin implementing Break4Brain Evolution in October 2026 and will use the programme during the academic year. Follow-up assessments will be conducted in February 2027, June 2027 and December 2027.

Inclusion Criteria: * Children aged 10 to 12 years. * Enrolled in Grade 5 or Grade 6 in a classroom participating in the cluster-randomized controlled trial. * Written informed consent provided by a parent or legal guardian. * Assent provided by the child. Exclusion Criteria: * Presence of a physical impairment. * Failure to provide parental or legal guardian informed consent. * Failure to provide child assent.