A Combined Inspiratory and Expiratory Muscle Training Program Improves Respiratory Muscle Strength and Fatigue in Multiple Sclerosis

Abstract

ObjectiveTo determine the effects of a short-duration, combined (inspiratory and expiratory), progressive resistance respiratory muscle training (RMT) protocol on respiratory muscle strength, fatigue, health-related quality of life, and functional performance in individuals with mild-to-moderate multiple sclerosis (MS). DesignQuasi-experimental before-after trial. SettingUniversity rehabilitation research laboratory. ParticipantsVolunteers with MS (N=21) were divided into 2 groups: RMT (n=11; 9 women, 2 men; mean age ± SD, 50.9±5.7y, mean Expanded Disability Status Scale score ± SD, 3.2±1.9) and a control group that did not train (n=10; 7 women, 3 men; mean age ± SD, 56.2±8.8y, mean Expanded Disability Status Scale score ± SD, 4.4±2.1). Expanded Disability Status Scale scores ranged from 1 to ≤6.5. No patients withdrew from the study. InterventionTraining was a 5-week combined progressive resistance RMT program, 3d/wk, 30 minutes per session. Main Outcome MeasuresThe primary outcome measures were maximal inspiratory pressure and expiratory pressure and the Modified Fatigue Impact Scale. All subjects completed secondary measures of pulmonary function, the six-minute walk test, the timed stair climb, the Multiple Sclerosis Self-Efficacy Scale, the Medical Outcomes Study 36-Item Short-Form Health Survey, and the Physical Activity Disability Scale. ResultsMaximal inspiratory pressure and expiratory pressure (mean ± SD) increased 35%±22% (P<.001) and 26%±17% (P<.001), respectively, whereas no changes were noted in the control group (12%±23% and −4%±17%, respectively). RMT improved fatigue (Modified Fatigue Impact Scale, P<.029), with no change or worsening in the control group. No changes were noted in the six-minute walk test, stair climb, Multiple Sclerosis Self-Efficacy Scale, or Physical Activity Disability Scale in the RMT group. The control group had decreases in emotional well-being and general health (Medical Outcomes Study 36-Item Short-Form Health Survey). ConclusionsA short-duration, combined RMT program improved inspiratory and expiratory muscle strength and reduced fatigue in patients with mild to moderate MS.