Promoção da qualidade de vida na fibromialgia por meio do exercício físico: perspectivas biopsicossociais e contribuições metodológicas

Abstract

Introduction: Fibromyalgia is a chronic, multifactorial musculoskeletal condition of high clinical complexity, characterized by widespread pain, fatigue, sleep disturbances, mood alterations, and substantial functional impairment. Although physical exercise is widely recommended as a nonpharmacological intervention, important gaps remain regarding optimal prescription parameters, comparisons between training intensities, the validity and specificity of diagnostic instruments, the integration of the biopsychosocial model, and factors associated with adherence to nonpharmacological treatment. Objectives: This thesis aimed to: (1) compare fibromyalgia symptoms with those of other chronic musculoskeletal pain conditions using instruments proposed by the American College of Rheumatology; (2) compare the effects of 24 sessions of resistance training with progressive versus constant intensity and walking on fibromyalgia impact and secondary clinical outcomes; (3) investigate biopsychosocial variables associated with social support, self-care, and fibromyalgia knowledge; and (4) examine clinical, sociodemographic, and social variables associated with exercise adherence in women with fibromyalgia. Methods: Four studies were conducted: one randomized controlled clinical trial, two cross-sectional studies, and one cohort study. Participants were adults diagnosed with fibromyalgia according to the 2016 criteria, predominantly physically inactive women. The interventions included resistance training with progressive intensity, resistance training with constant intensity, and moderate-intensity walking. Self-reported outcomes were assessed, including fibromyalgia impact, sleep quality, anxiety, depression, pain, perceived improvement, and treatment adherence. Pain mechanisms were evaluated through temporal summation, conditioned pain modulation, and cutaneous sensory thresholds. Musculoskeletal performance was assessed using isokinetic dynamometry and handgrip strength, in addition to walking ability. Statistical analyses included mixed linear models based on the intention-to-treat principle, logistic regression analyses, analyses of variance, and effect size calculations. Results: The instruments used to assess symptoms adequately discriminated individuals with fibromyalgia from those with other chronic musculoskeletal pain conditions and should not be applied outside this specific context. Twenty-four sessions of resistance training with progressive intensity did not result in greater reductions in fibromyalgia impact compared with constant-intensity resistance training or walking. All exercise modalities produced significant improvements across multiple clinical and physiological outcomes; however, these changes did not reach minimal clinically important differences. Resistance training with progressive intensity led to significant improvements in musculoskeletal performance, particularly in knee extension strength. Exercise adherence was low after three months without supervised intervention. Social support emerged as the primary protective factor for physical activity adherence. Social variables explained meaningful proportions of the variance in social support, self-care, and fibromyalgia knowledge scores. Conclusion: Physical exercise, regardless of modality or intensity progression strategy, provides clinical and physiological benefits for individuals with fibromyalgia; however, these benefits are insufficient to produce sustained, clinically meaningful changes. Different exercise modalities induce similar biological adaptations, highlighting the relevance of total workload and applied effort rather than specific training strategies. Treatment adherence remains a major challenge and is strongly associated with social factors, particularly social support. These findings underscore the need for an integrated biopsychosocial approach to the diagnosis, assessment, and nonpharmacological treatment of fibromyalgia.