Background and Objectives: Fibromyalgia (FM) is a chronic and complex condition characterized by widespread pain, fatigue, psychological burden, and cognitive impairment, posing significant challenges for treatment. Immersive virtual reality exercise (iVRE) has been proposed as an innovative therapeutic approach to increase adherence, motivation, and multidimensional benefits, but evidence in FM remains limited. This study aimed to evaluate the effects of a six-week iVRE program on cortisol levels, quality of life, cognitive function, and psychological symptoms in women with FM. Materials and Methods: A quasi-experimental pre–post design was conducted with 21 women (mean age 48.1 ± 10.7 years) diagnosed with FM, who completed twelve 30 min sessions of iVRE using Oculus Quest 2™ and the FitXR platform. Outcomes assessed pre- and post-intervention included salivary cortisol (ELISA), quality of life (FIQR), emotional status (DASS-21), and cognitive function (MoCA). Adherence and safety were monitored throughout. Results: The intervention was well tolerated, with no adverse events and 100% adherence. Statistically significant improvements were observed in FIQR scores (p < 0.001, d = 3.54), depression (p < 0.001, d = 1.19), anxiety (p < 0.001, d = 1.39), and stress (p < 0.001, d = 2.28). Cognitive performance improved significantly, with higher MoCA total scores (p < 0.001, d = 1.52) and better outcomes in visuospatial ability, language, and delayed recall domains. No significant changes were detected in salivary cortisol levels (p = 1.000). Conclusions: A six-week iVRE program is safe and feasible, promoting clinically relevant improvements in quality of life, emotional well-being, and cognitive function in women with FM, despite the absence of changes in cortisol. These findings highlight iVRE as a promising complementary therapeutic strategy within multidisciplinary FM management, warranting further controlled studies with larger samples and long-term follow-up to confirm its efficacy and explore underlying mechanisms.

INPLASY202520087 EFFECTIVENESS OF THE USE OF BLOOD FLOW RESTRICTION IN LOWER LIMB TENDONS. A REVIEW SYSTEMATICS Keywords: Blood flow restriction; Kaatsu; Tendon; Lower extremity tendinopathy; Tendi…

Background and Objectives: Comprehensive physical profiling is important for monitoring athletic development in youth soccer players (YSP), yet integrated data from competitive South American players remain limited. This study aimed to characterize the anthropometric profile, neuromuscular performance, and cardiorespiratory fitness of competitive Chilean YSP and explore associations among these components. Methods: This cross-sectional study included 24 male YSP from a Chilean professional club academy. Participants underwent anthropometric assessment, bilateral quadriceps isometric strength testing, vertical jump testing (Squat Jump [SJ], Countermovement Jump [CMJ], and Abalakov Jump [ABK]), and maximal cardiopulmonary exercise testing. The primary analysis was an integrated characterization of anthropometric, neuromuscular performance, and cardiorespiratory fitness. Secondary exploratory analyses included correlations with false discovery rate adjustment and multiple linear regression. Results: Participants had a median age of 13.5 years (IQR: 13.0–14.0) and a BMI of 21.1 ± 1.6 kg·m⁻². Mean bilateral quadriceps strength was 406.1 ± 70.0 N, while mean jump heights were 24.6 ± 4.2 cm for SJ, 28.4 ± 3.7 cm for CMJ, and 33.4 ± 5.3 cm for ABK. The average relative VO₂peak was 55.0 ± 4.7 mL·kg⁻¹·min⁻¹, while absolute VO₂peak was slightly higher than predicted. Bilateral quadriceps strength was positively associated with all three jumps before FDR adjustment; after FDR correction, the associations with CMJ and ABK remained statistically significant, whereas the association with SJ did not. Relative VO₂peak was not associated with CMJ performance. Conclusions: This study provides an integrated characterization of physical performance within this cohort of youth soccer players. Quadriceps strength was associated with vertical jump performance, whereas relative VO₂peak was not associated with CMJ, supporting assessment of neuromuscular and cardiorespiratory capacities.

Fibromyalgia is a chronic pain condition associated with reduced quality of life, psychological symptoms, cognitive impairment, and low adherence to exercise-based interventions. Immersive virtual reality (IVR) has gained attention as a rehabilitation approach; however, the relationship between user experience, adherence, and clinical outcomes remains unclear. This post hoc exploratory secondary analysis was derived from a randomized controlled clinical trial (NCT07605143) and included 16 women with fibromyalgia who completed a six-week IVR-based rehabilitation program. Associations between user experience, adherence, and clinical outcomes were explored among participants exposed to IVR. Quality of life was assessed using the Fibromyalgia Impact Questionnaire-Revised (FIQ-R), psychological symptoms using the Depression Anxiety Stress Scales (DASS-21), and user experience using the Player Experience of Need Satisfaction (PENS) questionnaire. Within-group changes were observed in FIQ-R scores (p = 0.001; d = 1.08) and DASS-21 stress levels (p = 0.025). Participants demonstrated favorable adherence and positive user experience. A significant correlation was identified between intuitive control and changes in depression scores (ρ = 0.63, p = 0.008). This exploratory analysis identified favorable user experience and adherence among women participating in an IVR-based rehabilitation program. However, due to the absence of a concurrent control group, no conclusions regarding treatment efficacy can be drawn. These findings should be considered hypothesis-generating.

Introduction: Lower limb tendinopathy is a common condition that leads to pain and functional limitations, particularly among physically active individuals. While high-load training promotes tendon adaptation, its early use in rehabilitation may aggravate symptoms. Blood flow restriction (BFR) training has emerged as a promising low-load alternative. Objective: To evaluate the effectiveness of BFR training on the structural and functional properties of lower limb tendons through a systematic review of controlled clinical trials. Methodology: Following PRISMA guidelines, five databases were searched up to March 2025. Five controlled clinical trials involving 232 participants with and without tendinopathy were included. Methodological quality was assessed using the Cochrane RoB 2 tool and the PEDro scale. Interventions involved low-load resistance exercise (20–35% 1RM) combined with BFR, compared against high-load training or no intervention. Results: Studies reported significant improvements in tendon thickness, cross-sectional area, and muscle strength with low-load BFR training. These outcomes were generally comparable to high-load protocols. However, acute responses varied across studies, with inconsistent changes in tendon thickness observed post-exercise. Discussion: BFR training appears to promote structural and functional improvements without requiring high loads, although more consistent studies are needed to standardize protocols and outcomes. Conclusion: BFR is a promising strategy for managing lower limb tendinopathies, especially when high-load exercise is contraindicated. More robust studies are needed to standardize protocols and explore long-term benefits in both clinical and athletic populations.