A combination of resistance and endurance training increases leg muscle strength in COPD:An evidence-based recommendation based on systematic review with meta-analyses

Resistance training (RT) is thought to be effective in preventing muscle depletion, whereas endurance training (ET) is known to improve exercise capacity and health-related quality of life (HRQoL) in chronic obstructive pulmonary disease (COPD). Our objectives were to assess the efficiency of combining RT with ET compared with ET alone. We identified eligible studies through a systematic multi-database search. One author checked titles and abstracts for relevance using broad inclusion criteria, whilst two independent authors checked the full-text copies for eligibility. Two authors independently extracted data, and we assessed the risk of bias and quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation guidelines. We included 11 randomized controlled trials (331 participants) and 2 previous systematic reviews. The meta-analyses showed equal improvements in HRQoL, walking distance and exercise capacity. However, we found moderate quality evidence of a significant increase in leg muscle strength favouring a combination of RT and ET (standardized mean difference of 0.69 (95% confidence interval: 0.39-0.98). In conclusion, we found significantly increased leg muscle strength favouring a combination of RT with ET compared with ET alone. Therefore, we recommend that RT should be incorporated in rehabilitation of COPD together with ET.