Respiratory muscle training in neuromuscular disease: long-term effects on strength and load perception

Med Sci Sports Exerc. 1999 Nov;31(11):1522-7. doi: 10.1097/00005768-199911000-00005.


Purpose: Deterioration of respiratory muscle function in patients with neuromuscular disorders is primarily responsible for the high morbidity and mortality associated with these diseases.

Methods: The potential benefit of respiratory muscle training (RMT) on preservation of respiratory muscle strength and respiratory load perception (RLP) was examined in 21 children (mean age: 12.2 +/- 1.8 yr [SD], 16 male) with Duchenne's muscular dystrophy or spinal muscular atrophy type III, and in 20 age-, weight-, and sex-matched controls. Subjects were randomly allocated to undergo incremental RMT with resistive inspiratory and expiratory loads for a period of 6 months (trained group, TR) or to perform similar exercises with no load (NT). Maximal static inspiratory (Pi(max)) and expiratory (Pe(max)) pressures and RLP (modified Borg visual analog scale 0-10) were assessed on two separate occasions before beginning of the training protocol, monthly throughout RMT duration, and every 3-6 months upon cessation of RMT for 1 yr.

Results: In controls, no significant changes in maximal static pressures or load perception occurred during RMT or thereafter. Training in neuromuscular disorder (NMD) patients was associated with improvements in Pi(max) (mean delta max: +19.8 +/- 3.8 cmH2O in TR vs +4.2 +/- 3.6 cmH2O in NT; P < 0.02) and in Pe(max) (mean delta max: +27.1 +/- 4.9 cmH2O in TR vs -1.8 +/- 3.4 cmH2O in NT; P < 0.004). Similarly, RLP significantly decreased during the RMT period in TR (mean delta: 1.9 +/- 0.3; P < 0.01) but did not change in NT (-0.2 +/- 0.2). In addition, with cessation of RMT, static pressures returned to pretraining values in TR within approximately 3 months. However, RLP was still improved after 12 months.

Conclusions: We conclude that in children with NMD, although RMT-induced increases in expiratory muscle strength are rapidly reversible, long-lasting improvements in RLP occur and could be associated with decreased respiratory symptoms.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Airway Resistance / physiology*
  • Analysis of Variance
  • Breathing Exercises*
  • Case-Control Studies
  • Child
  • Female
  • Follow-Up Studies
  • Humans
  • Inhalation / physiology
  • Longitudinal Studies
  • Male
  • Muscle Contraction / physiology*
  • Muscular Atrophy, Spinal / rehabilitation*
  • Muscular Dystrophy, Duchenne / rehabilitation*
  • Perception / physiology*
  • Pressure
  • Respiration
  • Respiratory Mechanics / physiology
  • Survival Rate