The goal of this clinical trial is to evaluate the newly developed Pocket PE 3-5 app, designed for use by teachers of 3rd-, 4th-, and 5th-grade students. Researchers will compare teachers and students in classrooms using the Pocket PE app with those in classrooms not using the app.

The main question it aims to answer is:

• Does the use of the Pocket PE 3-5 app improve classroom teacher PE self-efficacy and high-quality PE teaching behaviors, and promote students' moderate-to-vigorous physical activity participation in PE, as well as PE enjoyment and self-efficacy, compared to teachers who do not use Pocket PE 3-5?

Participants will:

• Randomly use Pocket PE 3-5 (12 intervention schools) for at least one PE class weekly, or not (12 control schools), for 12 consecutive weeks during the 2025/26 school year.
• Teachers will complete short surveys at 0 weeks (pre), 6 weeks (mid), and 13 weeks (post). Teachers in the intervention condition will complete a longer survey at 13 weeks (post-intervention) to provide feedback on the Pocket PE app. A random sub-sample of teachers in the intervention condition will be asked to participate in an exit interview to give additional input on Pocket PE 3-5 after the intervention has been completed.
• Students will complete brief surveys after PE classes at pre, mid, and post, and will wear wrist heart rate monitors during observed PE classes at these timepoints to measure their physical activity during PE.

We will also evaluate the level of implementation of Pocket PE 3-5 among teachers via class observations and objective data collected by the app.

Childhood physical inactivity is associated with a myriad of preventable health inequities among children, including greater prevalence and more severe childhood obesity, poorer cardiovascular and bone health, and lower levels of cognitive functioning, mental health, and self-esteem. While 43 states currently have laws mandating elementary school physical education (PE) to promote student public health objectives, most students do not achieve adequate PE participation because teachers (both PE certified and regular classroom teachers or paraprofessionals who teach PE) have limited or no access to easy-to-use and low-cost programmatic resources that address salient barriers for conducting effective, evidence-based, and standards-based PE.

The Pocket PE 3-5™ digital app (initially conceptualized as Aim to Play 3-5TM) is designed for 3rd - 5th grade teachers and students and works across common platforms and devices, online and offline, and provides simple, easy to use, standards-based PE lesson activities tailored by time, instructional setting (classroom, gym, outside), grade, student skill level, and equipment resources. The app is low-cost and includes brief teacher skill demonstration videos for each activity, along with printable activity cards, music, and audio cues to signal transitions to assist teachers and students with class management in 'real time' during PE. The program also includes embedded data tracking of PE minutes and completed instructional standards to assist with district and/or state-mandated reporting. Pocket PE 3-5 offers a technology-driven solution to promote the adoption of Comprehensive School Physical Activity Programs (CSPAPs) by providing a scalable, evidence-based resource to schools to promote high-quality PE participation among students.

To evaluate Pocket PE 3-5, we will conduct a cluster-randomized trial in 24 elementary schools, with one identified 3rd-, 4th-, and 5th-grade classroom teacher and their students in each school. Participating schools will be in California and Oregon and will be randomly assigned to receive Pocket PE 3-5 (n = 12 intervention schools) or not (n = 12 control schools) over a 12-week period. We anticipate that 72 teachers and approximately 1,800 students will participate. Assessments at pre, mid, and post program will primarily occur at the teacher level on PE class instruction, fidelity of implementation, and PE teaching self-efficacy. Teachers using Pocket PE (assigned to the intervention condition) will also provide feedback on the app, including usability, acceptability, and satisfaction. We will explore secondary student outcomes focused on objectively measured minutes of moderate-to-vigorous physical activity achieved during PE and PE enjoyment, as well as program satisfaction and enjoyment.

Hypothesis: Intervention teachers will improve their PE teaching self-efficacy and teaching practices, and students will participate in more moderate-to-vigorous physical activity during PE and have greater PE enjoyment and satisfaction, relative to the control group.

Inclusion Criteria for teachers:

• A 3rd, 4th, or 5th grade teacher at a participating school responsible for teaching PE at least one time a week;
• Able to read and understand English;
• Willing to use Pocket PE to facilitate their PE class instruction for 12 weeks;
• Be able to understand the study and consent to participate

Inclusion Criteria for students:

• A 3rd, 4th, or 5th grader enrolled in a participating class in a participating school;
• Able to read and understand English;
• Able to understand the study and assent to participation;

Exclusion Criteria:

• None