Loaded breathing tests will be performed to assess dyspnea intensity and unpleasantness, respiratory muscle recruitment patterns, respiratory effort and neural respiratory drive. Patients will be asked to breathe through a tapered flow resistive loading (TFRL) device (powerbreathe KH1) as long as they can (3-7 minutes), the resistance will be set at 50% of patients' PImax. Heart rate, oxygen saturation, and number of breaths will be monitored. Before and after the test Borg dyspnea, inspiratory effort and unpleasantness will be recorded. The test will be repeated after 8 weeks of IMT, at the same resistance. Borg dyspnea, inspiratory effort and unpleasantness will be recorded at time limit of pre-training and at the symptom limit. The longest time for post training can be up to 15 minutes.