Implementing efforts made in community settings to provide social support for increasing physical activity are recommended based on strong evidence of their effectiveness in increasing physical activity and improving physical fitness among adults. Social support interventions focus on changing physical activity behavior through building, strengthening, and maintaining social networks that provide supportive relationships for behavior change (e.g., setting up a buddy system, making contracts with others to complete specified levels of physical activity, or setting up walking groups or other groups to provide friendship and support).