Postural drainage and assisted coughing increase sputum production acutely, but do not influence the long term outlook of patients with COPD. Breathing exercises of various types are capable of increasing the tidal volume and reducing the functional residual capacity. However, the effects on pulmonary gas exchange and also on the long term improvement in breathing pattern have not been established. More needs to be learned regarding the acute effects of breathing exercises on lung mechanics and pulmonary gas exchange and on the maintenance of improvement in the long term.