Mobility and stretching exercise program delivered through the Rehbody platform (AI/CV-assisted) in addition to usual care. The program includes seven specific exercises.

Cumulative intervention consisting of the mobility and stretching program described in Arm 1 plus AI/CV-assisted resistance training delivered through Rehbody, in addition to usual care. Total: 11 exercises.

Continuation of usual care, including medical management, pharmacological treatment, and conventional physiotherapy when applicable.

Frequency: Twice weekly. Intensity: Borg Rating of Perceived Exertion (RPE) scale 4-6/10. Number of exercises: 11.

Sets and repetitions:

2 sets of 10-15 repetitions for mobility exercises. 10-12 repetitions for resistance training exercises. 4 repetitions for stretching exercises.

Rest interval: 20-60 seconds between sets. Total intervention duration: 12 weeks.

Mobility exercises (10-15 minutes):

Overhead Shoulder Raise (Bodyweight) Right Knee Raise with Arm Movement (Standing) Left Knee Raise with Arm Movement (Standing) Full Left Ankle Dorsiflexion-Plantarflexion (Standing) Full Right Ankle Dorsiflexion-Plantarflexion (Standing)

Resistance training exercises (15-20 minutes):

6. Weighted Deadlift 7. Chair Squat 8. Weighted Lateral Shoulder Raise 9. Bilateral Dumbbell Bent-Over Row

Stretching exercises (5 minutes):

10. Seated Cervical Flexion Stretch 11. Kneeling Prayer Stretch

The Fibromyalgia Impact Questionnaire-Revised (FIQ-R) is a 21-item self-reported instrument that assesses physical function, overall impact, and symptom severity in individuals with fibromyalgia. The Chilean validated version demonstrates excellent internal consistency (Cronbach's α = 0.91), good test-retest reliability (ICC = 0.90), and adequate convergent validity through significant correlations with pain intensity, pain interference, symptom severity, and health-related quality of life (Escobar, 2018). Total scores range from 0 to 100, with higher scores indicating greater disease impact. The questionnaire requires approximately 1.3 minutes to complete (Carrasco-Vega et al., 2023). A 14% change in the total FIQ-R score was considered the Minimal Detectable Change (MDC) (Bennett, Friend, et al., 2009). Assessments will be conducted at baseline (Week 0), post-intervention (Week 13), and follow-up (Week 25).

The 30-Second Sit-to-Stand Test (30s-STS) assesses lower-limb strength through a physical performance measure. It has demonstrated good to excellent test-retest reliability (ICC: 0.85-0.91), adequate known-groups validity for distinguishing individuals with and without fibromyalgia, and a minimal detectable change of ≥3 repetitions (Socorro-Cumplido et al., 2024). The test is associated with handgrip strength, muscle mass, balance, functional capacity, overall physical performance, and mobility- and quality of life-related outcomes (Kakavas et al., 2020; Khuna et al., 2024). Participants are instructed to perform as many sit-to-stand repetitions as possible within 30 seconds without using their arms, while the assessor records the total number of repetitions. The 30s-STS has been validated for remote administration in telehealth settings and for use in the Chilean population. Assessments will be conducted at baseline (Week 0), post-intervention (Week 13), and follow-up (Week 25).

It will be assessed using The 4-item Pain Catastrophizing Scale (PCS-4) is a shortened version of the original 13-item Pain Catastrophizing Scale designed to assess catastrophic thinking related to pain in individuals with musculoskeletal conditions. The Spanish version has been validated in the Chilean population and demonstrates a unidimensional structure, high internal consistency (Cronbach's α = 0.84; McDonald's ω = 0.84), and evidence of validity through associations with pain intensity, pain interference, and kinesiophobia (Bascour-Sandoval et al., 2022). The questionnaire is self-administered and consists of four items rated on a 5-point Likert scale from 0 ("not at all") to 4 ("all the time"). Total scores range from 0 to 16, with higher scores indicating greater levels of pain catastrophizing. Assessments will be conducted at baseline (Week 0), post-intervention (Week 13), and follow-up (Week 25).