Effects of High-Intensity Interval Training on Pulmonary Function and Exercise Capacity in Individuals with Chronic Obstructive Pulmonary Disease: A Meta-Analysis and Systematic Review

Introduction This study aimed to examine the effectiveness of high-intensity interval training (HIIT) on pulmonary function and exercise capacity in individuals with chronic obstructive pulmonary disease (COPD). Methods Ten databases (PubMed, the Cochrane Library, Web of Science, EMBASE, MEDLINE, CINAHL, CNKI, Wanfang, Weipu, and CBM) were searched for relevant articles published from inception to 30 June 2020. Studies were included if they were randomized controlled trials (RCTs) comparing a HIIT group with usual care or other training groups. Quality was assessed using the Physiotherapy Evidence Database (PEDro) scale, and the overall quality of evidence was assessed using the GRADE approach. The primary outcomes were peak VO2 and FEV1% predicted, and the secondary outcomes were FEV1/FVC, peak V-E, peak WR, 6MWD, dyspnea, health-related quality of life, and adverse event. Results Twelve articles (689 patients) were included. HIIT was shown to have a positive effect on exercise capacity (peak WR, 6MWD), pulmonary function (FEV1% pred, peak V-E), dyspnea, and quality of life. However, sensitivity analyses for dyspnea were unstable, and the result changed from positive to negative after removing one study (SMD = - 0.13, 95% CI [- 0.44, 0.17], P = 0.40). Conclusions HIIT could improve pulmonary function, exercise capacity, and quality of life but may not decrease dyspnea in patients with COPD. It can be recommended as a safe and effective exercise modality in rehabilitation programs. Given that the overall results were based on a limited number of studies with significant heterogeneity and some of the results were based on low GRADE rating evidence, more high-quality, larger sample size, multicenter, and long-term follow-up RCTs are needed to confirm the clinical efficacy of HIIT in patients with COPD. PROSPERO Registration CRD42020165897.