Inclusion Criteria:  Adult (age 18+) History of bariatric surgery (gastric bypass or sleeve gastrectomy) at one of two academic medical centers within the past 6-12 months Interest in increasing physical activity Low physical activity, defined as <200 minutes/week self-reported moderate- to-vigorous physical activity Access to telephone for study sessions Able to read and speak English  Exclusion Criteria:  Cognitive deficits precluding participation or informed consent Illness likely to lead to death in the next 6 months Inability to be physically active (e.g., severe arthritis) Participation in another program targeting physical activity besides their standard offerings at the surgery center.