Coronary heart disease is the leading cause of death and disability worldwide. Guidelines recommend that all coronary heart disease patients should be offered cardiac rehabilitation which includes exercise programmes, education, and ongoing support within both clinical and community settings following a heart-related event, surgery or procedure.

The core cardiac rehabilitation programme (previously known as Phase III) is delivered by a clinical team in hospital. Depending on the location, it may involve a combination of exercise training, health education, and advice on reducing the risk of having a heart-related event such as ways to manage stress. After the patients complete this programme, participants are assessed for suitability to attend a community-based exercise programme called the maintenance cardiac rehabilitation programme (previously Phase IV). Cardiac rehabilitation programmes reduce the risk of death and illness, but evidence shows that it is unlikely that patients will maintain the required exercise levels without the support and structure provided by such exercise programmes. A previous study found that using behaviour change techniques, such as problem-solving skills, encouraged participants to stay active for longer. New ways to encourage coronary heart disease patients to stay active both during and after taking part in cardiac rehabilitation programmes are needed. The aim of this project is to translate behaviour change research in a cardiac rehabilitation programme to encourage coronary heart disease patients to stay active for longer.

The aim of this project is to translate behaviour change research into current maintenance stage (Phase IV) cardiac rehabilitation services. The hypothesis is that by adding a lifestyle change programme promoting self-efficacy, physical activity (PA) changes will be maintained following a cardiac rehabilitation programme.

All participants will be recruited while taking part in Active Belfast maintenance stage cardiac rehabilitation (CR) programmes. Participants will have already completed the Phase III core cardiac rehabilitation programme and been assessed for suitability to take part in the study. Some participants will be randomly chosen to receive the intervention which includes additional sessions to encourage active lifestyles. This will involve wearing a pedometer to count steps. Each week, participants will report their step counts and review their goals. In week eight, participants will have a group discussion with the researcher during which participants will discuss the benefits of physical activity. In week twelve, there will be a second group discussion about potential barriers to being active with advice on practical ways to do more activity. Participants will receive a monthly phone call from the exercise professional to check their progress and encourage them to adhere to the programme and achieve their weekly goals.

Participants in the control group will receive the standard cardiac rehabilitation maintenance programme. After the study, all participants will receive a pedometer and be given instructions on how to use it as well as a booklet from the Public Health Agency to advise them on how to increase their physical activity. Participants' physical activity will be measured using activity monitors at the beginning of the study, at twelve weeks (end of maintenance stage cardiac rehabilitation programme) and then at six months. Body measurements such as height, weight and blood pressure will also be taken, as well as a measure their physical and mental health. The difference in steps and time spent in moderate-vigorous physical activity between the intervention group and the control group after six months will be analysed. How well the intervention has been completed by participants (i.e. attendance records) and delivered by the exercise professional (i.e. satisfaction with the programme) will be assessed through interviews and focus groups. The cost-effective the study will also be evaluated.