Effects of Inspiratory Muscle Training in Persons With Advanced Multiple Sclerosis

During the 10-week training period, participants will perform exercises using a Threshold Inspiratory Muscle Trainer (IMT) at 3 sets of 15 repetitions per day. The initial resistance of the IMT unit will be at 30% of participants' maximum inspiratory pressure (MIP). Resistance for the IMT unit will be increased progressively and adjusted weekly by a licensed physical therapist based on participant's MIP at baseline, Borg perceived rate of exertion, and symptoms.