Chest
Volume 120, Issue 3, September 2001, Pages 748-756
Journal home page for Chest

Clinical Investigations
Muscle Strength
Inspiratory Muscle Training in Patients With COPD: Effect on Dyspnea, Exercise Performance, and Quality of Life

https://doi.org/10.1378/chest.120.3.748Get rights and content

Abstract

Objective

The aim of the study was to assess the effect of target-flow inspiratory muscle training (IMT) on respiratory muscle function, exercise performance, dyspnea, and health-related quality of life (HRQL) in patients with COPD.

Patients and methods

Twenty patients with severe COPD were randomly assigned to a training group (group T) or to a control group (group C) following a double-blind procedure. Patients in group T (n = 10) trained with 60 to 70% maximal sustained inspiratory pressure (SIPmax) as a training load, and those in group C (n = 10) received no training. Group T trained at home for 30 min daily, 6 days a week for 6 months.

Measurements

The measurements performed included spirometry, SIPmax, inspiratory muscle strength, and exercise capacity, which included maximal oxygen uptake (

o2), and minute ventilation (
e). Exercise performance was evaluated by the distance walked in the shuttle walking test (SWT). Changes in dyspnea and HRQL also were measured.

Results

Results showed significant increases in SIPmax, maximal inspiratory pressure, and SWT only in group T (p < 0.003, p < 0.003, and p < 0.001, respectively), with significant differences after 6 months between the two groups (p < 0.003, p < 0.003, and p < 0.05, respectively). The levels of

o2 and
e did not change in either group. The values for transitional dyspnea index and HRQL improved in group T at 6 months in comparison with group C (p < 0.003 and p < 0.003, respectively).

Conclusions

We conclude that targeted IMT relieves dyspnea, increases the capacity to walk, and improves HRQL in COPD patients.

Section snippets

Patients

Twenty patients with COPD were selected from the outpatient clinic. Patients were randomly assigned to the training group (group T) or to a control group (group C) on a double-blind basis. Table 1 shows the baseline characteristics of the patients. All patients had severe airflow obstruction (ie, FEV1< 50%) and were included with the presence of COPD as defined by the American Thoracic Society.9 Patients were in stable condition and were free of any clinical evidence of cardiovascular,

Results

All selected patients completed the study. There were no significant differences between the two groups at the start of the study. The general characteristics and pulmonary function data are presented in Table 1.

Discussion

This study shows that in COPD patients, IMT at home using an incentive flowmeter device (target-flow) diminishes dyspnea and improves respiratory muscle function, exercise performance, and HRQL.

The baseline characteristics of the two groups were similar. Although the trained patients were not supervised while performing the training at home, we assume from the tests performed in the laboratory throughout the study period that they followed the same regimen at home. In addition, the study shows

References (36)

  • R Dekhuijzen et al.

    Target-flow inspiratory muscle training during pulmonary rehabilitation in patients with COPD

    Chest

    (1991)
  • K Smith et al.

    Respiratory muscle training in chronic airflow limitation: a meta-analysis

    Am Rev Respir Dis

    (1992)
  • MJ Belman et al.

    Targeted resistive ventilatory muscle training in chronic obstructive pulmonary disease

    J Appl Physiol

    (1988)
  • GH Guyatt et al.

    A measure of quality of life for clinical trials in chronic lung disease

    Thorax

    (1987)
  • American Thoracic Society

    Standards for the diagnosis and care of patients with chronic obstructive pulmonary disease (COPD) and asthma

    Am J Respir Crit Care Med

    (1995)
  • GAV Borg

    Physiological basis of perceived exertion

    Med Sci Sports Exerc

    (1982)
  • JF Morris et al.

    Spirometric standards for healthy nonsmoking adults

    Am Rev Respir Dis

    (1971)
  • J Martyn et al.

    Measurement of inspiratory muscle performance with incremental threshold loading

    Am Rev Respir Dis

    (1987)
  • Cited by (109)

    • Is the six-minute step test able to reflect the severity and symptoms based on cat score?

      2023, Heart and Lung
      Citation Excerpt :

      The highest score determined by the CAT found that patients with fewer steps were patients with mild and mild to moderate clinical impact, as well as the inverse behavior with the lowest CAT score who climbed the most step. Patients with COPD have decreased functional capacity and increased dyspnea on minimal exertion as the disease progresses,11–25 thus compromising performance in the 6MST. Furthermore, in the linear regression analysis, the FEV1 (L) and the CAT score were able to influence 29% of the 6MST performance.

    • Inspiratory muscle training improves autonomic modulation and exercise tolerance in chronic obstructive pulmonary disease subjects: A randomized-controlled trial

      2019, Respiratory Physiology and Neurobiology
      Citation Excerpt :

      Additionally, these changes were associated with increases in the 6MWT distance. Furthermore, Riera et al. 2001, showed that IMT at 60% and 70% of PImax promoted increases in walking capacity, sleep quality, but no changes in peak VO2 were found (HS et al., 2001). However, Berry et al. in 1996, showed that IMT at 80% of the PImax during six weeks in combination with general exercise training is not more effective than exercise training alone (Berry et al., 1996).

    View all citing articles on Scopus

    Supported by “Junta de Andalucia” grant No. 94//535–119.

    View full text