Investigators will conduct a hybrid implementation-effectiveness trial of an adapted Comprehensive School Physical Activity Program (CSPAP) intervention. A clustered stepped wedge design will be used, with the duration of the trial being 3 years.

The Comprehensive School Physical Activity Program (CSPAP) is a multi-component approach by which schools use all opportunities for students to be physically active in 5 domains: physical education; physical activity during school; physical activity before and after school; staff involvement; and family and community engagement. Overall, CSPAP-based interventions have had small effect sizes in impacting youth PA, with larger effect sizes seen when more CSPAP domains are included. CSPAP-based interventions may be particularly beneficial for students attending schools located in communities with the fewest out of school resources for PA. There is thus a critical need to effectively support schools in increasing PA opportunities with an emphasis on meeting the PA-related needs of youth who have limited access to opportunities for physical activity, sports, and outdoor recreation.

The effectiveness and implementation of a flexible, systems-level intervention to increase opportunities for PA in middle schools will be studied. The intervention seeks to support middle schools in increasing opportunities for PA practices in all CSPAP domains-addressing two core systems-level barriers to such implementation (staffing and teacher/staff training) and building in flexibility for setting-specific needs assessment and action planning. Core components include (1) provision of a dedicated staff member (via Americorps or other organization) to support school PA (via direct staffing and capacity building), (2) setting-specific needs assessment and action planning, and (3) professional development opportunities for teachers, staff, and coaches related to the provision of PA across CSPAP domains.

The study will use a stepped wedge design with a total of 7 middle schools, in which each school will be randomized to start the intervention at different time points. All schools will provide baseline data and will later switch to the intervention phase in random order and in 3 waves. Based on feasibility considerations, 2 schools will switch from control phase to intervention phase in wedge 1, 3 schools will be in wedge 2, and 2 schools will be in wedge 3. Each 2-year intervention phase will be followed by a year when data will be collected to assess sustainability of the intervention. In total, there will be approximately 15 control phase data collections, 20 intervention phase data collections, for a total of 1800 student-assessments. This study will:

1. Assess how intervention exposure is associated with student (accelerometer-measured) PA
2. Assess how intervention exposure is associated with student depression and anxiety
3. Assess how intervention exposure is associated with change in PA opportunities at the school level
4. Explore systems-level barriers and facilitators to successful intervention implementation and maintenance.

Adolescent Inclusion Criteria:

• Age 11-14 (inclusive)
• Attend one of the participating schools during the study period

Teacher/Staff Inclusion Criteria:

• Age 18 or older
• Work at one of the participating schools during the study period