High-intensity interval training improves cardiovascular and physical health in patients with rheumatoid arthritis: a multicentre randomised controlled trial

Objectives Patients with rheumatoid arthritis (RA) have substantially elevated risk for cardiovascular diseases, and low cardiorespiratory fitness (VO 2 max) is a major mediator. The aim of this assessor-blinded, two-armed multicentre randomised controlled trial was to evaluate the effects of high-intensity interval training (HIIT) and strength exercise on cardiovascular health, physical fitness and overall health in patients with RA. Methods In total, 87 patients (86% female; aged 20–60 years) were randomly assigned to an intervention group (IG) or a control group (CG). The IG performed HIIT and strength exercise for 12 weeks. The CG was instructed to be physically active on a moderately intensive level, ≥150 min/week. Primary outcome was change in VO 2 max. Secondary outcomes were changes in anthropometry measures, muscle strength, overall health (Visual Analogue Scale (VAS)-Global), Patient Global Impression of Change (PGIC), pain and disease activity (Disease Activity Score in 28 joints (DAS28)). Results There was a significant mean group difference of change on VO 2 max (3.71 mL/kg/min; 95% CI 2.16, 5.25) in favour of the IG. Significant mean group differences of change were also seen for O 2 -pulse (1.38; 95% CI 0.85 to 1.91), waist circumference (−2.6; 95% CI −5.09 to –0.18), 1-minute sit-to-stand (5.0; 95% CI 3.35 to 6.72), handgrip strength (28.5; 95% CI 3.80 to 52.8), overall health (−14.7; 95% CI –23.8 to –5.50) and PGIC (p<0.0001) in favour of the IG. No significant mean group differences of change were found for pain (−4.0; 95% CI −13.07 to 5.06), DAS28 (−0.25; 95% CI −0.60 to 0.10) and erythrocyte sedimentation rate (−0.64; 95% CI −3.23 to 1.90). Conclusion Supervised HIIT and strength exercise improved cardiovascular health, physical fitness and overall health without a deterioration in pain and disease activity and should be considered in patients with well-controlled RA. Trial registration number NCT05768165 .