Everyone with Chronic Obstructive Pulmonary Disease (COPD) who is able to exercise should be offered pulmonary rehabilitation (PR). Participants will be invited to take part in the study after being referred for PR by members of Queen Alexandra Hospital (QAH), Portsmouth Hospitals NHS Trust clinical team. They will be given a PIS for the patient to contact the study team to arrange an appointment, or alternatively if verbal consent is obtained the research team will contact the patient to arrange an assessment appointment. Potential participants will also be identified from databases from selected GP who meet the protocol inclusion and exclusion criteria. These potential participants will be sent a study participation invitation letter and asked to contact the respiratory research team at QAH to arrange an assessment appointment.