Purpose: Pulmonary rehabilitation (PR) is essential to manage patients with COPD. The aim of this study was to investigate the appropriate intensity of PR exercise training for patients with moderate-to-severe COPD.
Patients and methods: A prospective multicenter randomized controlled trial was conducted from January 2014 to October 2018. The subjects were randomly assigned to three groups with different intensities of PR, according to their maximum oxygen uptake percentage determined by cardiopulmonary exercise testing. After 20 weeks of exercise training, the effects of low-, moderate-, and high-intensity exercise interventions on patients were compared to determine the most appropriate PR prescription.
Results: For patients with moderate COPD, all the measured parameters were significantly improved in the moderate- and high-intensity PR groups (P <0.01), while there was no significant difference in the frequency of acute exacerbations and the mMRC questionnaire after 20 weeks of PR exercise in the low-intensity PR group. For patients with severe COPD, all variables were also improved in the high-intensity PR group (P <0.05), while the mean differences of pre- and post-PR were lower than those in patients with moderate COPD. Moreover, the Hamilton Anxiety Scale and body mass index showed no significant difference in low-intensity PR group (P >0.05).
Conclusion: High-intensity PR exercise is helpful for patients with moderate to severe COPD. Moderate COPD patients need to receive intensive PR training; the improvement degrees from PR intervention were higher than those of the severe COPD patients. For patients with severe COPD, high-intensity PR exercise may be more beneficial if patients can tolerate it.
Keywords: chronic obstructive pulmonary disease, cardiopulmonary exercise testing, exercise therapy, pulmonary rehabilitation