Inspiratory Muscle Training in Pulmonary Hypertension

32 patients with PH will perform: 1) pulmonary function tests; 2) measurement of maximal inspiratory pressure (MIP) and endurance; 3) six-minute walk test and 5) incremental and constant load cardiopulmonary exercise test (\~ 75% of maximal work-rate) and step test. Inspiratory muscle training will consist of twice daily sessions of 30 breaths (\~ 50% PiMAX, 4-5 minutes per session) for 8 weeks. The SHAM group will perform sessions of 30 breaths with no inspiratory load.