Effect of exercise interventions on oxygen uptake in people with chronic obstructive pulmonary disease: A network meta-analysis of randomized controlled trials

Background: Although aerobic training leads to physiological improvements in people with chronic obstructive pulmonary disease (COPD), measured by the VO2 peak, there is no evidence as to which type of physical exercise intervention is the most effective in improving the VO₂ peak or max.

Objective: A network meta-analysis (NMA) was performed to determine the effects of different physical interventions on oxygen uptake in people with COPD.

Methods: A literature search was performed from database inception to February 2024. Randomized controlled trials on the effectiveness of exercise programs on oxygen uptake with COPD were included. We assessed the risk of bias using the Cochrane Risk of Bias (RoB 2.0) tool and the quality of the evidence using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool. Pairwise meta-analyses and NMAs were performed for direct and indirect evidence.

Results: A total of 22 studies were included in this NMA. The highest effects for improvement in oxygen uptake scores were for continuous, moderate-intensity endurance exercise versus a control (effect size [ES]: 1.17; 95% CI 0.59 to 1.74), followed by continuous, high-intensity endurance exercise versus a control (ES: 0.47; 95% CI 0.08 to 0.85), and combined exercise versus a control (ES: 0.41; 95% CI 0.18 to 0.64).

Conclusions: Continuous, moderate-intensity endurance exercise should be considered the most effective strategy to improve oxygen uptake in people with COPD, followed by continuous, high-intensity endurance exercise and combined exercise. Due to the importance of VO₂ as a predictor of quality of life and mortality in people with COPD, it is essential to include its assessment in clinical guidelines and to include the most effective physical activity interventions to improve it.

Trial registration: PROSPERO database: CRD42023425893.