Cardiac Rehabilitation and the 'active couch potato' phenomenon.

Participants attending a phase II (outpatient) cardiac rehabilitation program will be included in this study. The outpatient cardiac rehabilitation program involves exercise and education sessions (1 hour each), twice a week, for 6 weeks. Participants physical activity levels and sedentary behaviour will be observed over 7-days at the start and end of the cardiac rehabilitation program, and at 6 and 12 months after admission into the cardiac rehabilitation program. One of the core components of cardiac rehabilitation is to increase participants exercise capacity and physical activity levels, aiming to achieve the public health physical activity guidelines (150 minutes of moderate-to-vigorous physical activity per week). There is some evidence in healthy adults that even if you achieve the physical activity guidelines, if you sit for too long, you are more likely to die from any cause (the active couch potato phenomenon). It is unknown if the active couch potato phenomenon exists in cardiac rehabilitation participants, and if it exists what effect this has on risk factors for heart disease. This is an observational study and eligible cardiac rehabilitation participants’ will be encouraged to adhere to the cardiac rehabilitation program, with no additional encouragement to change their physical activity and/or sedentary behaviour provided over the 12-month data collection period.