Participants in the physical activity program will participate in 12 weekly 1.5-hour sessions focused on increasing physical activity. The group sessions will include participating in physical activity as well as group discussions on the barriers and opportunities for increasing physical activity in their daily life. The 12-week program covers educational topics related to physical activity (e.g. overcoming barriers to activity, exercising safely, relapse prevention strategies) and the program gradually increases the amount of physical activity completed during the group sessions over the course of the 12 weeks. Over a 3-month wait period, individuals in the wait-list control group will be offered monthly sessions on health and wellness topics before being offered the physical activity program. Measurement visits will occur at baseline, at the end of the12-week program, and approximately 12-weeks after the end of the intervention. During the measurement sessions participants will complete assessments related to their physical activity and other health behaviors.