Patients with chronic lung diseases such as Chronic Obstructive Pulmonary Disease (COPD), who perform regular physical activity, have improved health and wellbeing compared with those who do little exercise. The purpose of the study is to evaluate whether the use of a simple pedometer (step counter) to set targets for daily physical activity can encourage COPD patients referred for an 8-week pulmonary exercise based programme (PR) to be more active. The investigators also want to know whether the use of pedometers during PR can improve adherence, self-management and outcome in COPD.