1. To test a Social Cognitive Theory-based model of physical activity adoption among sedentary endometrial cancer survivors receiving an intervention to increase physical activity. The model includes hypotheses about the effect of self-efficacy and outcome expectations on physical activity adherence, the effects of four sources of efficacy information (mastery experience, verbal persuasion, modeling, and physiological feedback) on self-efficacy and subsequent exercise adherence, and the influence of physical activity outcomes on subsequent self-efficacy, outcome expectations, and physical activity.