50k4Life: A SMART study protocol to improve walking engagement in public school employees on the US-Mexico border

INTRODUCTION: Mexican Americans living in the U.S.-Mexico border region suffer disproportionately from preventable cardiometabolic and cancer diseases. Workplace health promotion programs that include physical activity promotion are promising strategies to address this public health problem to improve physical activity engagement. Workplace-based programs can increase moderate to vigorous physical activity (MVPA) engagement while addressing barriers associated with inactivity. METHODS: We plan to conduct a clustered Sequential Multiple Assignment Randomized Trial (SMART) to determine the effectiveness of a workplace walking challenge intervention - 50,000 for Life (50K4Life) - in improving brisk walking engagement (at least 7000 steps/day, representing approximately 50,000 steps/week) for public school employees. The two-phase trial will include 30 public schools in two cohorts (15 per cohort) with predominantly Mexican American employees from El Paso County area schools in Texas on the U.S.-Mexico border. In Phase 1, the schools will be randomly assigned to 50K4Life or 50K4Life plus app-based push notifications. In Phase 2, schools with 50 % or more participants accumulating 50,000 steps/week will continue receiving the same intervention. The remaining schools will be randomly assigned to receive individual or school-level intervention. As part of our intervention evaluation, we will conduct a process and cost-effectiveness evaluation to provide insight into cost and scalability. DISCUSSION: This study will provide evidence to support the implementation of walking challenge-based interventions that improve engagement among Mexican Americans living in the U.S.-Mexico border region.