Patients with Chronic Obstructive Pulmonary Disease are characterised by a sedentary lifestyle. This contributes to increase the number of hospitalizations and mortality. Changing this lifestyle is a major objective of the management of these patients. Pulmonary rehabilitation helps patients to increase their fitness, but modifying a longstanding sedentary habit is more difficult to achieve. This project aims at modifying patients' long term physical activity with a physical activity coaching programme. This will help patients to transform the benefits of pulmonary rehabilitation into a healthier active lifestyle and contribute to reduce hospitalizations, increase quality of life and survival.