**3.10 Adjunct to exercise training in pulmonary rehabilitation programs**

Another potential application of NPPV in patients with severe stable COPD is to enhance exercise training during rehabilitation. It has been shown that when delivered during cycle ergometry, CPAP, pressure-support ventilation, and proportional-assist ventilation all reduce inspiratory effort and dyspnea in hypercapnic COPD patients (Petrof, Calderini, & Gottfried 1990; Bianchi et al. 1998). Recent studies in patients with severe COPD in a 6-week exercise training program has reported that, NPPV alone was more effective than supplemental oxygen alone as adjunct to physical exercise in improving submaximal exercise tolerance and health related quality of life (HRQOL) (Borghi-Silva et al. 2010). These studies demonstrated that NPPV can be used to increase or prolong the intensity of exercise training sessions in patients with severe COPD.
