High-intensity interval and resistance training programme improves pain and fatigue outcomes in people with systemic sclerosis: a European multicentre randomised controlled trial
Question
Does a tailored 12-week supervised combined HIIT and resistance-training program reduce pain and fatigue, and improve quality of life, function, depression, strength/endurance, and cardiorespiratory fitness, compared with usual care in people with systemic sclerosis?
Summary
In a six-centre European randomized controlled trial, 170 adults with systemic sclerosis were assigned to 12 weeks of usual care or usual care plus a supervised twice-weekly upper-body exercise program combining HIIT and resistance training. At 12 weeks, the exercise group improved more than usual care on the primary pain and fatigue outcomes, with additional improvements in depression, systemic sclerosis quality of life, self-reported function, upper-body strength/endurance, and arm-crank cardiorespiratory fitness. Exercise-related side effects were not reported, but the protocol excluded people with active exacerbations or severe cardiopulmonary involvement.
Methodology
- Adults with systemic sclerosis, mostly women and mostly limited cutaneous systemic sclerosis, clinically cleared to exercise.
- 170 participants.
- Upper-body HIIT and upper-body resistance circuit training.
- Work intervals: 30 seconds at 100% peak power output.
- Recovery: 30 seconds passive recovery.
- Intensity: HIIT at 100% PPO; resistance training at 75%-80% 1RM.
- About 60 minutes.
- Twice weekly.
- 12 weeks.
- European multicentre, parallel-group, superiority, assessor- and statistician-blinded randomized controlled trial with 1:1 allocation.
- Pain, Fatigue, Cardiorespiratory fitness, and Musculoskeletal strength and endurance were tracked.
Outcomes
Fatigue
FACIT-F total improved more with exercise than usual care at 12 weeks.
Mean difference in change scores -10.4 points (95% CI -19.4 to -1.4), p<0.05.
Pain
VAS pain improved more with exercise than usual care at 12 weeks.
Mean difference in change scores 0.48 (95% CI 0.21 to 0.76), p<0.05; VAS pain p<0.001, ES=0.6 by independent t-test.
Cardiorespiratory fitness
Exercise improved arm-crank VO2peak while usual care declined at 12 weeks; benefits were lost by 24 weeks.
VO2peak mL/kg/min mean difference in change scores -3.1 (95% CI -4.6 to -1.6); abstract reports cardiorespiratory fitness p<0.001.
Adverse events
No major or minor exercise-related side effects occurred.
One moderate expected epileptic seizure occurred before exercise started and was deemed unrelated.
Insights
- In screened clinical populations, HIIT evidence should be framed around supervision, medical clearance, and monitoring rather than direct consumer self-prescription.
- A 30-second work/30-second passive-recovery HIIT structure can be embedded in a broader twice-weekly program, but this study combined it with resistance training.
- Benefits were strongest at the supervised 12-week endpoint and did not clearly persist after supervision ended.
Limitations
- Combined intervention prevents isolating the independent contribution of HIIT.
- Participants and providers were not blinded.
- Different physiological assessment equipment across sites could increase variability.
- Other non-pharmacological treatments alongside usual care were not systematically collected.
- The protocol excluded many screened patients with exacerbations or severe complications.
Safety
- No major or minor exercise-related side effects occurred.
- One participant in the exercise group had a moderate expected epileptic seizure before starting the program, required hospitalization, and the event was deemed unrelated to exercise.
- The study excluded active exacerbations and severe cardiac or pulmonary involvement and used screening plus session monitoring.