Exercise for treating fibromyalgia syndrome.

BACKGROUND: Fibromyalgia (FMS) is a syndrome expressed by chronic widespread body pain which leads to reduced physical function and frequent use of health care services. Exercise training is commonly recommended as a treatment.

OBJECTIVES: The objective of this systematic review was to examine the efficacy of exercise training as an treatment for FMS.

SEARCH STRATEGY: We searched 6 electronic bibliographies for studies of exercise training in FMS: MEDLINE (1966-12/2000), CINAHL (1982-12/2000), HealthSTAR (1990-12/2000), Sports Discus (1975-05/2000), EMBASE (1974-05/2000) and the Cochrane Controlled Trials Register (2000, issue 4). We also reviewed the reference lists from identified articles including reviews and meta-analyses of treatment studies.

SELECTION CRITERIA: Randomized trials focused on cardiorespiratory endurance, muscle strength and/or flexibility as treatment for FMS were selected.

DATA COLLECTION AND ANALYSIS: Two reviewers independently identified trials meeting inclusion criteria, rated the methodologic quality using 2 standardized validated instruments, evaluated the adequacy of the exercise training stimulus using the American College of Sports Medicine (ACSM) criteria and evaluated the results. Disagreements were resolved through active discussion and consensus. High quality training studies had scores of 50% or greater on van Tulder methodologic criteria and met the minimum training standards of ACSM. Outcome variables were grouped into 7 constructs: pain, tender points, physical function, global well being, self efficacy, fatigue & sleep, and psychological function. Two reviewers independently extracted data on study characteristics, results and point estimates for selected variables, and used consensus to address discrepancies.

MAIN RESULTS: Sixteen trials involving a total of 724 participants were assigned at random to: exercise intervention groups (n=379), control groups (n=277), or groups receiving an alternate treatment (n=68). Seven studies were high quality training studies: 4 aerobic training, 1 a mixture of aerobic, strength and flexibility training, 1 strength training and 2 with exercise training as part of a composite treatment. Flexibility protocols were never described in sufficient detail to allow evaluation. The four high quality aerobic training studies reported significantly greater improvements in the exercise groups versus control groups in aerobic performance (17.1% increase in aerobic performance with exercise versus 0.5% increase in the control groups), tender point pain pressure threshold (28.1% increase versus 7.0% decrease) and improvements in pain (11.4% decrease in pain versus 1.6% increase). Poor description of exercise protocols was common, with insufficient information on intensity, duration, frequency and mode of exercise. Adverse events were also poorly reported.

REVIEWER'S CONCLUSIONS: Supervised aerobic exercise training has beneficial effects on physical capacity and FMS symptoms. Strength training may also have benefits on some FMS symptoms. Further studies on muscle strengthening and flexibility are needed. Research on the long-term benefit of exercise for FMS is needed.