Impact of High-Intensity Interval Training on Disease Activity and Disease in Patients With Psoriatic Arthritis: A Randomized Controlled Trial

Objective To evaluate the impact of high-intensity interval training (HIIT) on disease activity and disease perception in patients with psoriatic arthritis (PsA) and to evaluate whether a potential effect could be sustained for a longer period of time. Methods We randomly assigned 67 patients with PsA (43 women and 24 men) to an intervention group in which patients performed HIIT for 11 weeks or a control group of patients who were instructed not to change their physical exercise habits. Outcomes were assessed at 3 months and 9 months with the patient's global assessment (PGA), fatigue, and pain scores measured on a 100-mm visual analog scale (VAS), and the composite Disease Activity Score in 44 joints (DAS44) was calculated. We used linear mixed models to calculate the mean difference (95% confidence interval [95% CI]) between groups according to the intent-to-treat principle. Results At 3 months, there was no clear difference in the PGA score (-0.49 [95% CI -10.91, 9.94]), DAS44 (-0.08 [95% CI -0.36, 0.20]), or pain intensity (5.45 [95% CI -4.36, 15.26]) between the groups. However, patients in the intervention group reported less fatigue (-12.83 [95% CI -25.88, 0.23]) than those in the control group. There was no evidence of long-term effects of HIIT on outcomes measured at 9 months. Conclusion HIIT showed no clear effects on disease activity markers in patients with PsA, but the intervention (exercise) group reported meaningfully less fatigue after the intervention period. The results of this study suggest that patients with PsA tolerate HIIT without deterioration of disease activity and with improvement in fatigue.