Resistive inspiratory muscle training and exercise performance in COPD patients. A comparative study with conventional breathing retraining.

Twenty patients with stable COPD (mean age 67.8 yr; mean FEV1 1.08 1), all limited by ventilation at maximum exercise, were randomly allocated after a four week control period, to an eight week programme of either inspiratory resistive training (IRT), with a P Flex device, or conventional breathing retraining (BR).