Exercise reduces the risk of cardiovascular disease (CVD) and promotes health. Most people in the United States do not exercise regularly. Nurses can promote exercise using the proposed theory as a guide. This theory of exercise was developed through triangulation ofOrem's self-care deficit theory of nursing, the transtheoretical model of exercise behavior, and characteristics of a population at risk for CVD. Practice theory and use of individual constructs were reviewed, revised, and validated by experts familiar with the organizing constructs. Future testing and evaluation of practice theory as a guide for promoting exercise is planned.