High-intensity exercise improves strength and aerobic capacity in rheumatoid arthritis patients compared to low-intensity exercise

BackgroundCurrently, the evidence for the effectiveness of exercise in patients with rheumatoid arthritis (RA) is controversial.ObjectiveTo determine the effectiveness of high-intensity exercise on physical function and disease activity in patients with RA.MethodsThis systematic review was prospectively registered with PROSPERO (CRD42022332312). Electronic searches were performed in MEDLINE, Web of Science, EMBASE, SCOPUS, CINAHL, SPORTDiscus, Epistemonikos, and LILACS databases from inception to September 2025. Randomised clinical trials that evaluated the effectiveness of high-intensity exercise on physical function and disease activity in patients with RA were included. The selection of studies, data extraction, and risk of bias assessment were performed by two independent reviewers.ResultsEleven clinical trials met the eligibility criteria. For the comparison of high-intensity exercise versus supervised or unsupervised low-intensity exercise, there was no significant difference between groups: the standard mean difference (SMD) was 0.03 (95% CI, -0.15 to 0.20;  = 0.77) for physical function, and 0.06 (95% CI, -0.13 to 0.25;  = 0.53) for disease activity at 20-24 weeks. Conversely, high-intensity exercise was significantly more effective in improving knee extensor muscle strength (SMD = 0.30; 95% CI, 0.13 to 0.48;  < 0.001) and aerobic capacity (SMD = 0.35; 95% CI, 0.15 to 0.55;  < 0.001) than supervised or unsupervised low-intensity exercise at 20-24 weeks. No adverse events related to the interventions were reported in any of the included studies.ConclusionHigh-intensity exercises compared to supervised or unsupervised low-intensity exercise did not significantly improve self-reported physical function and disease activity in patients with RA. In addition, high-intensity exercise is safe and effective in significantly improving extensor muscle strength and aerobic capacity in this population. According to the GRADE approach, the quality of evidence was very low to high. More clinical trials are needed to confirm these findings.