Effectiveness of Endurance Training Combined with Strength Exercises on Muscle Strength Gains in Rheumatoid Arthritis: A Systematic Review

Abstract Rheumatoid arthritis (RA) is a chronic, autoimmune, systemic inflammatory disease. RA mainly affects the synovial membrane of the joints and surrounding tissues. Disease progression can lead to joint deformities, which restrict mobility and contribute to reduced muscle strength. The aim of this study was to identify, critically evaluate, and systematically synthesize all available scientific evidence on the effectiveness of endurance exercise combined with muscle strength training (ST) in RA. Indexed databases were included, such as PubMed, Web of Science, Embase, Scopus, Latin American and Caribbean Health Sciences (LiLACS), Cochrane, as well as gray literature databases: Google Scholar, Open Gray, and ProQuest. There were no limitations on period or language. The risk of bias was assessed using the Cochrane Risk of Bias 2 tool by two independent reviewers. The primary outcome was muscle strength and secondary outcomes were functional incapacity, disease activity, and quality of life. Initially, 1.605 records were found, 1,461 in the main databases and 144 in the gray literature. Four studies were included in this review. Supervised programs, lasting 8 to 24 weeks and with an intensity between 40 to 80% of 1RM and 60 to 80% of HRmax, showed significant improvement in muscle strength (gains of 15–35%) and reduction in disease activity, without inflammatory exacerbation. There was also a decrease in functional disability (mean reduction of 0.42) and a trend toward improvement in quality of life. Combined endurance and ST, applied at moderate to high intensity (40–80% of 1RM; 60–80% of HRmax), proved effective for patients with RA, promoting increased muscle strength, functional improvement, and reduced disease activity without aggravating the inflammatory process.