Inspiratory Muscle Training With Powerbreath Device in Patients With Fibromyalgia

Inspiratory muscle training with Powerbreath IMT device, for a duration of 8 weeks. Each day, each subject perform 5 sets of 10 repetitions, 5 days a week. The endurance of the device increases along the study, initiating with the 50% of their own maximum inspiratory pressure (MIP) during the first week, 2nd week: 55% MIP, 3rd week: 60% MIP, 4th week: 65% MIP, 5th week: 70% MIP, 6th week: 75% MIP, 7th week: 80% MIP and 8th week:80% MIP