High-intensity exercise for maintained health-enhancing physical activity in patients with rheumatoid arthritis: a randomised controlled trial
Question
Does a 12-week supervised high-intensity interval training and strength exercise intervention increase and maintain health-enhancing physical activity, assessed by accelerometry and self-report, over 6 and 12 months in patients with rheumatoid arthritis compared with counselling and a home exercise program?
Summary
This secondary analysis of a multicentre randomized controlled trial tested whether a 12-week supervised high-intensity exercise program helped adults with rheumatoid arthritis maintain health-enhancing physical activity at 6 and 12 months. Eighty-seven patients with low-to-moderate disease activity or remission were randomized to supervised HIIT plus strength exercise or to counselling plus a home exercise program. The intervention group had greater self-reported bicycling at 6 months and greater accelerometer-derived vigorous physical activity and self-reported strength exercise at 12 months, while sedentary time and moderate physical activity did not differ significantly. Most intervention participants adhered to at least 80% of the prescribed protocol, but one participant had irregular heart rate during HIIT and several reported musculoskeletal pain requiring modification.
Methodology
- Eighty-seven adults with rheumatoid arthritis, mostly female, aged 20-60 years, with stable anti-rheumatic medication and low-to-moderate disease activity or remission.
- 87 participants.
- Bicycle ergometer HIIT plus strength exercise for large muscle groups.
- Intensity: HIIT bouts at 90%-95% HRmax; strength exercise at 70%-80% one-repetition maximum.
- Two supervised sessions/week plus an encouraged third non-supervised cardiorespiratory session.
- 12 weeks.
- Secondary analysis of a randomized controlled multicentre trial with 6- and 12-month follow-up.
- Relative vigorous physical activity, Relative moderate physical activity, Sedentary time, and Self-reported bicycling and strength exercise were tracked.
Outcomes
Bicycling at 6 months
The intervention group was more likely than control to report bicycling at 6 months.
OR 6.6, 95% CI 1.29 to 34.27, p=0.0239; adjusted OR 6.6, 95% CI 1.27 to 34.38, p=0.0250.
Relative vigorous physical activity at 12 months
The intervention group maintained or increased accelerometer-derived vigorous physical activity more than control at 12 months.
Intervention effect 4.7 min/day, 95% CI 0.82 to 8.51, p=0.0177; adjusted 3.2 min/day, 95% CI 0.18 to 6.24, p=0.0377.
Strength exercise at 12 months
The intervention group was more likely than control to report strength exercise at 12 months.
OR 23.1, 95% CI 1.64 to 327.13, p=0.0204; adjusted OR 25.4, 95% CI 1.74 to 369.56, p=0.0183.
Relative moderate physical activity and sedentary time
No significant intervention effects were found for accelerometer-derived moderate physical activity or sedentary time at either follow-up.
RMPA p=0.6324 at 6 months and p=0.4227 at 12 months; sedentary time p=0.2721 at 6 months and p=0.4937 at 12 months.
Adherence and safety
Most intervention participants met the adherence threshold, but there were reported symptom events requiring modification.
37/43 (86%) adhered to at least 80% of the prescribed protocol; one irregular heart-rate event, four temporary musculoskeletal pain reports, and one persistent musculoskeletal pain report.
Insights
- In screened rheumatoid arthritis patients, a supervised 12-week high-intensity exercise block may support longer-term vigorous activity and continuation of bicycling or strength exercise.
- Clinical HIIT programming for rheumatoid arthritis should include heart-rate monitoring, professional oversight, and clear modification pathways for musculoskeletal pain and abnormal rhythm symptoms.
- Accelerometer-only follow-up can miss non-ambulatory activities that matter for interval and strength programs.
Limitations
- Secondary analysis; parent trial power calculation was based on VO2max, not physical activity outcomes.
- Exact HIIT work-rest structure and total session duration were not reported in the article text.
- Accelerometers did not capture non-ambulatory activities such as bicycling and strength exercise.
- Self-report activity measures may be biased by memory, perception, understanding, or social desirability.
- Generalizability is limited to screened patients with rheumatoid arthritis and low-to-moderate disease activity or remission.
Safety
- One patient experienced irregular heart rate during supervised HIIT and completed at moderate intensity after referral for ultrasound cardiography.
- Four patients reported temporarily increased musculoskeletal pain during strength exercise, managed with temporary exercise modification.
- One patient reported persistent musculoskeletal pain after half of the exercise period and completed the intervention without strength exercise.