Comparison of the effects of high and low-moderate load lower limb resistance training on muscle strength and exercise capacity in individuals with COPD: A systematic review and meta-analysis

Background: Extrapulmonary changes also occur in COPD. Resistance training can increase muscle strength and exercise capacity.Objective: The objective of this systematic review was to examine and compare the effectiveness of high and low-moderate load lower limb resistance training on muscle strength and exercise capacity in individuals with stable chronic obstructive pulmonary disease (COPD).Methods: The PubMed/Medline, Scopus, Cochrane Library, ClinicalTrials.gov, Web of Science, EBSCO, and CINAHL databases were searched to identify the articles published in English between January 1970 and July 2023.Results: Seven randomized controlled trials with a total of 188 individuals with COPD (RT: 100, CG: 88) met the inclusion criteria. A significant difference was revealed (favoring high load) in the change in knee extensor muscle strength and leg press strength in the high load resistance training group compared to the low-moderate load resistance training group (MD 21.90 Nm, 95 % CI 17.46-26.34 Nm, p < 0.00001; MD 5.80 kg, 95 % CI 3.87-7.73 kg, p < 0.00001). A significant difference was observed in the change in 6 MWT (six minute walk test) distance (favoring low-moderate load) and VO2peak (peak oxygen uptake) (favoring high load) in the high load resistance training group compared to the low-moderate load resistance training group (MD -16.90 m, 95 % CI -29.76- -4.04 m, p < 0.010; MD 3.10 ml/kg/min, 95 % CI 2.65-3.55 ml/kg/min, p < 0.00001).Conclusion: This systematic review and meta-analysis demonstrated that both high-load and low-moderate load resistance training increased muscle strength and might increase exercise capacity.