Cardiac rehabilitation is a programme of exercise and health advice for people recovering from heart disease. Pulmonary rehabilitation is a similar programme for people with chronic lung disease. For both groups of patients, taking part in rehabilitation can lead to improvements in health and well-being. However, only 30% of patients complete their agreed rehabilitation programme. This costs the NHS millions of pounds every year. This project aims to investigate whether a motivational-based intervention, underpinned by self-determination theory and motivational interviewing, will enable staff to encourage more patients to take part in physical activity (PA). Staff will be trained with the new communication skills and will then deliver the rehabilitation programme. The session content will not change, just the way in which staff speak to patients.