Promoting Physical Activity and Fitness Among Underserved Latino Families Living in U.S.-Mexico Border Regions - Project Summary/Abstract The U.S. and Mexico share similar population disease patterns such as high rates of chronic diseases (e.g., heart disease and obesity). Individuals residing in border regions often travel back and forth between the U.S. and Mexico, which exposes them to both different and similar obesogenic, socio-cultural, and physical environments. This frequent transnational interaction has led researchers to classify border cities as one region that should be studied as a whole. As such, it is important to systematically study border populations and develop effective interventions and public policy for this region. This study will test the efficacy and sustainability of a 12- month family-centered behavioral cluster randomized intervention, Athletes for Life (AFL), plus a 1-year active sustainability phase in community recreation centers in San Diego, California (U.S.) and Mexicali, Baja California (Mexico). This study will also assess intervention implementation outcomes, including program acceptability and feasibility by families and community recreation center staff. A total of 8 community recreation centers and 290 parent/child dyads (4 in San Diego and 4 in Mexicali) will be randomized to either a control group consisting of standard recreation center classes (delivered by regular recreation center staff) or an experimental group consisting of the multilevel AFL behavioral intervention (delivered by study staff). This study aims to increase total habitual physical activity (PA) and cardiovascular fitness (CVF) in a U.S.-Mexico transborder population that experiences disproportionately high rates of obesity. We will harness our research team's extensive experience in developing multi-level interventions to promote behavior change among Latinos, and leverage a strong community-academic collaboration that maximizes community impact and sustainability. The long-term goal of this project is to reduce cardiovascular disease and cardiometabolic risk factors among underserved children and their families in the US-Mexico border region. This research will provide novel empirical evidence for the efficacy, scalability, and sustainability of a multilevel fitness- and lifestyle-oriented family approach delivered in collaboration with community centers among underserved Latino families in the U.S.-Mexico border region.