Effect of inspiratory muscle training in patients with multiple sclerosis

OBJECTIVE: To evaluate whether inspiratory muscle training (IMT) improves inspiratory muscle strength, respiratory capacity, fatigue, and subjective perception of physical endurance in patients with advanced multiple sclerosis (MS).

DESIGN: Randomized controlled trial.

SETTING: Outpatient clinic in Sweden.

PARTICIPANTS: Fifteen severely disabled patients with MS, randomized to a training or control group.

INTERVENTION: Seven patients trained with a Threshold inspiratory muscle trainer, twice every other day, with 3 sets of 10 loaded inspirations (40%-60% of patients' maximal inspiratory pressure [Pimax]) over a 10-week period.

MAIN OUTCOME MEASURES: Spirometry, Pimax, maximal expiratory pressure (Pemax), clinical assessments, and questionnaires on the patients' fatigue severity and physical endurance were evaluated.

RESULTS: After training, the Pimax (P<.008) and Pemax (P<.02) increased in the training group. The improvement in Pimax after 10 weeks of training was higher than the improvement in the control group (P<.01) and was maintained 1 month after the training period ended. The training affected neither respiratory function nor the patients' symptoms.

CONCLUSIONS: IMT had a beneficial effect on inspiratory muscle strength in patients with MS and is recommended as a complement to ordinary physical training.