The objective of the studies presented in this paper was to examine whether the need to belong can be used to enhance exercise cognitions and behavior. Two studies examined the effectiveness of framing exercise as a means of boosting social skills (versus health benefits) for self-regulatory efficacy, exercise intentions, and (in Study 2) exercise behavior. In Study 1, inactive adults primed to feel a lack of social belonging revealed that this manipulation led to greater self-regulatory efficacy (but not exercise intentions). In Study 2, involving a sample of inactive lonely adults, all participants reported engaging in more exercise; however, those in the social skills condition also reported a greater sense of belonging than those in the health benefits comparison condition. These findings provide an important basis for developing physical activity interventions that might be particularly relevant for people at risk for feeling socially isolated or lonely.