FIBROSTEPS: Study Protocol for a 2 × 2 Factorial Randomized Controlled Trial Evaluating Group Exercise and Somatic Tracking in Fibromyalgia

Fibromyalgia (FM) causes widespread pain, poor sleep, fatigue, and reduced quality of life. Exercise is the best supported non-pharmacological treatment, yet many patients report that it is insufficient on its own. Somatic tracking is a component of pain reprocessing therapy. It is promising in chronic back pain but untested as a stand-alone intervention in FM. The Fibromyalgia Somatic Tracking and Exercise Program Study (FIBROSTEPS) is a single-center 2 × 2 factorial randomized controlled superiority trial estimating the separate and combined effects of group exercise and somatic tracking on the impact of FM. Two hundred adults aged 18–65 years, of either sex, with FM diagnosed by the 2016 criteria, are randomized 1:1:1:1 after an 8-week baseline period to general activity recommendations plus usual care (control), supervised group exercise, somatic tracking, or both. Both interventions run for 16 weeks with one session per week (45 min physiotherapist-led group exercise; 40 min guided somatic tracking with a certified therapist). The primary outcome is change in total original Fibromyalgia Impact Questionnaire score (0–100) from week 8 to week 24, analyzed by intention-to-treat. Secondary outcomes include insomnia severity, daily pain intensity, and Fitbit-measured activity and sleep. The trial has 80% power for the two main effects; the exercise × somatic-tracking interaction is prespecified as exploratory. No results are reported; the trial will provide randomized evidence on somatic tracking in FM, alone and combined with exercise, informing multi-component FM rehabilitation. Trial Registration: ClinicalTrials.gov (NCT06922747). Ethics Approval: Regional Committee for Medical and Health Research Ethics (REK), reference 2025/853403.