Background: Physical activity is recommended for patients with systemic lupus erythematosus (SLE), yet most patients do not meet guideline-based activity levels, and fatigue remains a major unmet need. Fatigue is one of the most disabling symptoms in patients with SLE and is often insufficiently controlled by pharmacological treatment. Exercise interventions, particularly high-intensity interval training (HIIT), have shown promising effects on fatigue and physical function in other inflammatory diseases, but evidence in SLE remains limited [1].

Objectives: This study aimed to evaluate the feasibility, effects and safety of a structured HIIT–based rehabilitation program on physical performance and fatigue in patients with SLE [2].

Methods: ActiLup was a monocentric, prospective proof-of-concept study embedded in a 28-week design, including a 12-week baseline observation, a 4-week supervised inpatient rehabilitation with HIIT, and a 12-week follow-up. Adults with SLE and moderate to severe fatigue underwent individualized endurance and strength training, including supervised HIIT sessions in addition to the recommendations of the Amercian College of Sports Medicine (ASCM). Primary outcomes were changes in peak oxygen uptake (VO ₂ peak) and fatigue assessed by FACIT-F and FSMC. Secondary outcomes included functional performance, disease activity, quality of life, and objectively measured physical activity. Statistical analyses focused on within-subject changes over time using repeated-measures ANOVA with sphericity testing and Bonferroni-corrected post-hoc comparisons, complemented by t-tests or nonparametric tests as appropriate and effect sizes (Cohen’s d/f) [2].

Results: 30 patients reached the primary endpoint, and 28 completed follow-up.

The study population had a mean age of 47.3 ± 11.2 years, with a mean disease duration of 97.5 ± SD 102.3 months. The majority of the cohort was female (93.3 %, n = 28). At baseline, VO

₂

peak was 20.42 ± 4.9 ml/kg/min and weekly step count was 65274 ± 32286.

VO

₂

peak increased significantly during rehabilitation (+1.8 ml/kg/min, p < 0.01) and remained above baseline at follow-up. Functional performance improved markedly, with significant gains in chair-stand repetitions (p < 0.01). Fatigue severity improved significantly on the FACIT-F scale (+7.8 points, p < 0.01), exceeding the threshold for clinically relevant fatigue. Disease activity remained stable throughout the intervention period. Importantly, no disease flares and no serious exercise-related adverse events occurred during the HIIT program.

Conclusions: A structured HIIT-based rehabilitation program was feasible, safe, and effective in patients with SLE and fatigue. The intervention led to meaningful improvements in aerobic capacity, functional performance, and fatigue without worsening disease activity, supporting the integration of higher-intensity exercise into multidisciplinary SLE care.

The study was funded by GSK (ISS 213382).

REFERENCES: [1] Dreher M, Köppel M, Baumann FT et al. Rheuma in motion-A positioning of exercise and movement therapy in chronic inflammatory rheumatic diseases. Z Rheumatol 2025; 84: 425-437. doi:10.1007/s00393-025-01693-1.

[2] Dreher M, Petros S, Engelhardt S et al. ActiLup: is it feasible? High-intensity interval training in systemic lupus erythematosus patients with fatigue: protocol for a prospective, monocentric proof-of-concept study. BMJ Open Sport & Exercise Medicine 2025; 11: e002403. doi:10.1136/bmjsem-2024-002403.

Acknowledgments: NIL.

Disclosure of Interests: Matthias Dreher I am a speaker for UCB, Lilly and Chugai -> but not associated with EULAR or the lecture, ActiLup was funded by GSK (ISS 213382), Sarah Engelhardt: None declared, Laura Geselle: None declared, Sameer Petros: None declared, Tobias Wicke: None declared, Johannes Babb: None declared, Andreas Schwarting Andreas Schwarting is a speaker for GSK, ActiLup was funded by GSK (ISS 213382).