Less than half of the adults in the United States meet national guidelines for physical activity. Physical activity programs can induce short-term improvements in physical activity. To develop effective interventions, researchers and practitioners should consider the timing, location, and social structure patterns of participants. Using a pretest, posttest study design, 329 adults in a weight loss program completed surveys on their patterns and physical activity participation. Men preferred weight lifting, cycling, and jogging, whereas women preferred walking and aerobics. Black participants preferred being active in the home. Additionally, participating in a mix of group and individual activities compared with individual-only activities was predictive of posttest moderate-to-vigorous intensity and total physical activity. Providing a variety of activities for adults in both location and social structure may lead to sustained physical activity participation. (Contains 4 tables.)