Most existing cardiac rehabilitation programs have little ability to expand participation using traditional delivery models that emphasize supervised, facility-based programs. Furthermore, facility-based programs to promote physical activity behavior in patients with coronary artery disease (CAD) are limited in their impact because most patients are unwilling to travel more than 30-45 minutes to participate in a program. The University of Ottawa Heart Institute Prevention and Rehabilitation Centre (Ottawa, Canada) has developed a telephone-based counseling program, specifically to support heart patients in becoming more physically active. The study will involve patients either participating in a 12-month physical activity counseling (PAC) program, or receiving usual care after they are discharged from hospital. For patients assigned to the PAC group, a face-to-face meeting with a physical activity counselor will occur within 10 days to 2 weeks after being discharged from hospital. At this time the patient will be provided with a personalized physical activity program which will be tailored based on prior activity levels, clinical history, and recovery. The PAC patients will also receive eight telephone-based counseling sessions at 2, 4, 8, 14, 20 and 24 weeks, and 2 telephone maintenance contacts at 40 and 52 weeks after hospital discharge. Each telephone call is scheduled to last 10-15 minutes. For patients assigned to the usual care (UC) group, they will receive the physical activity advice and care usually provided to patients discharged from hospital. Following hospitalization, usual care typically includes a follow-up visit(s) with your cardiologist and/or family doctor. If requested, an activity program will be provided to usual care group participants after the study has finished. In addition, the patients will also be required to complete five research questionnaires, and two telephone interviews. The study will track all participants for a period of one year from the time they are discharged from hospital. Over the next twelve months 252 patients from the Ottawa Heart Institute are expected to take part in the study.