Effectiveness of physical activity in reducing pain in patients with fibromyalgia: a blinded randomized clinical trial.

The purpose of this study was to evaluate and compare the effectiveness of muscle-strengthening exercises (MS) and a walking program (WA) in reducing pain in patients with fibromyalgia. Ninety women, 30-55 years of age, diagnosed with fibromyalgia according to the American College of Rheumatology 1990 criteria, were randomized into 3 groups: WA Group, MS Group, and control group. Pain (visual analog scale) was evaluated as the primary outcome. Physical functioning (Fibromyalgia Impact Questionnaire, FIQ), health-related quality of life (Short-Form 36 Health Survey, SF-36), and use of medication were evaluated as secondary outcomes. Assessments were performed at baseline, 8, 16, and 28 weeks. Intention-to-treat and efficacy analyses were conducted. Sixty-eight patients completed the treatment protocol. All 3 groups showed improvement after the 16-week treatment compared to baseline. At the 28-week follow-up, pain reduction was similar for the WA and MS groups (P = 0.39), but different from the control group (P = 0.01). At the end of the treatment, 80% of subjects in the control group took pain medication, but only 46.7% in the WA and 41.4% in the MS groups. Mean FIQ total scores were lower for the WA and MS groups (P = 0.96) compared with the control group (P < 0.01). Patients in the WA and MS groups reported higher scores (better health status) than controls in almost all SF-36 subscales. MS was as effective as WA in reducing pain regarding all study variables; however, symptoms management during the follow-up period was more efficient in the WA group.