Engaging in regular physical activity (PA) contributes to positive health outcomes, including longevity, better quality of life, and reduced incidence of cardiovascular diseases, diabetes, depression, certain cancers, and obesity; however, only a minority of U.S. adults meet the minimum guidelines for moderate to vigorous PA (MVPA), and Latinos are less likely than whites to report meeting the guidelines. Public parks comprise local infrastructure that can be leveraged for community PA, but tend to be underutilized, particularly in low-income communities. Parks in low-income and minority communities tend to have less PA programming, especially targeting adults, and higher crime and other factors that affect park use. There is a need for interventions that address community concerns, target the built environment, and "activate" park use. Churches are credible, stable entities that have significant reach within Latino communities and a history of social service provision and advocacy related to health and well-being. The investigators' prior research has found that church-based interventions can be effective across a wide range of health issues and types of churches. This study combines approaches from the research team's extensive prior work with churches and parks to conduct a cluster randomized controlled trial of a multi-level intervention that links Latino Catholic churches (n=14) with their local parks to increase PA among Latino parishioners (n=1204) in Los Angeles. The specific aims are to: (1) Examine the impact of a multi-level church-based intervention that links Catholic parishes to their local parks on Latino parishioners' PA and health-related outcomes (effects on parishioners' MVPA and self-reported PA, heart rate/fitness, waist circumference, waist to hip ratio, body fat, mental health, and perceived social support for PA); (2) Explore differences in the effectiveness of the intervention by gender; and (3) Evaluate factors associated with intervention implementation (facilitators, barriers, fidelity, and replication costs) for future dissemination. The approach targets multiple levels to promote health-enhancing PA through park-based fitness classes led by kinesiology students, peer leader-led walking groups, park-based church events, and church-based PA support activities. It integrates churches' vast social networks, moral authority, and influence with parks' structural and organizational capacity and kinesiology student interns' professional expertise. The intervention makes use of innovative partnerships within and across sectors - faith-based, local parks/city government, and local universities. The inter-sectoral, collaborative approach makes the intervention scalable and sustainable in real-world settings and incorporates action at multiple levels (individuals, churches, and neighborhoods). To the investigators' knowledge, this will be the first study to examine the effectiveness of an integrated church and park-based intervention on Latinos' PA, and it will provide a sustainable model of PA programming in low-income communities. If the intervention proves effective, the increased community capacity through this partnership will lay the groundwork for scale-up across the largest diocese in the U.S. and, potentially, the nation.