Stakeholders' perspectives on barriers and facilitators to implementing extra physical activity in secondary schools to improve adolescents' health and academic performance.

Introduction: There is an association between physical activity and both health and academic performance. However, there is still a lack of consensus on how to engage adolescents in physical activity interventions in secondary schools. One approach to better understand the activities and strategies supporting effective implementation is to involve school staff and adolescents in the early stages of planning and preparing for interventions. Therefore, the aim of this study is to explore how multiple stakeholders, including school staff, students, and experts, perceive the barriers and facilitators for implementing a school-based intervention that extends the school day with additional physical activity in Sweden. Material and methods: This inductive explorative qualitative study involved 16 participants. Three focus groups with school staff, including principals ( Results: Three categories emerged: (1) "types of activities offered", highlighting the importance of designing activities that are fun, inclusive and unusual; (2) "integration of the activities into school curriculum" to promote sustainability of the intervention and incorporate physical activity throughout the school day and across school subjects, and (3) "Management support and funding" referring to the funded time and facilities that teachers leading the activities need to facilitate implementation. Conclusions: Before implementing extra physical activity in a school setting, it is important to understand what activities enhance students' motivation and the type of support teachers need from the school principal and administration. This includes funding for teachers' time, appropriate scheduling of the activities, and access to facilities.