Why is this review important?

Fibromyalgia is a complex disorder with symptoms of chronic musculoskeletal pain, tenderness, fatigue, stiffness, physical exhaustion, and unrefreshing sleep, co-occurring with psychological conditions of mood, stress, anxiety, depression, and cognitive problems such as memory loss. Fibromyalgia as a spectrum has complex pathogenesis involving the central-peripheral nervous system and commonly overlapping with somatic syndromes such as gastrointestinal pain or irritability, temporomandibular joint dysfunction, insomnia, etc. It is debilitating for the physical and psychosocial functionality of an individual and has far-reaching implications for the person’s family, employment opportunities, independence, and quality of life. Hence, an evidence-based multidimensional and multidisciplinary treatment is required.

This review accordingly targets evidence from interventional studies that have a multi-modality approach and mixed-exercise training programs.

What is this review about?

The aim of the review was to evaluate the benefits and harms of mixed-exercise interventions in adults (>18 years of age) diagnosed with fibromyalgia.

Mixed intervention was defined as programs that included two or more forms of exercises (combinations of aerobic, resistance, flexibility, agility, coordination, balance, therapeutic exercises, warm-up, warm-down, and/or belly dance). Reviewers compared mixed-exercise management versus control conditions including no intervention, wait list, drug treatment, participant education, biofeedback, relaxation, cognitive behavioural therapy, and other mono-exercise interventions, such as remedial exercise, flexibility, and posture. The mixed programs were fully or partially supervised, with average duration of 14 weeks (minimum two sessions per week of 45 to 60 minutes each).

This review included 29 randomized control trials conducted in 12 different countries up to December 2017 and consisting of 2,088 participants in a mixed-exercise group and 1,065 in a control group (19 studies). Out of all of the studies, 70% included only female participants, such that 98% (2,028) of the total participants were females.

Major outcomes were health-related quality of life, pain intensity, fatigue, stiffness, physical function, a number of participants who withdrew (dropped out), and adverse events. Adverse events were injuries and exacerbations of pain and/or other fibromyalgia symptoms during intervention. Three minor outcomes were submaximal cardiorespiratory function, muscle strength, and total participants with reduction in pain intensity greater than 30%. These outcomes were measured at 3 time points: baseline, post-treatment, and long-term follow-up (6 to 52 weeks).

Who will be interested in this review?

Prevalence of fibromyalgia is reported as 1% to 2% of people in the United States, 2.1% to 2.9% in Europe, and 2.7% globally with a 3:1 female to male ratio. This review will help patients with fibromyalgia, their family members and caregivers, health professionals dealing with fibromyalgia, professionals working with chronic-pain syndromes, general practitioners, etc.

What did the evidence from this review tell us?

Twenty-one trials (1,253 participants) provided moderate-quality evidence for all of the major outcomes except stiffness (low quality). All major-outcome parameters were self-reported, with the exception of withdrawals and adverse events. These parameters were expressed on a 100-point scale (0 to 100). After 5 to 26 weeks of a multi-exercise program, people who exercised were 7% better in absolute measures: pain was improved by 5%, fatigue by 13%, stiffness by 7%, and physical function by 11%. Participants who exercised rated their quality of life at 49 points, and people in the control group rated their quality of life at 56 points.

Across the 21 studies producing moderate-quality evidence, no injuries or other adverse events were reported. Although some participants experienced increased fibromyalgia symptoms (pain, soreness, or tiredness) during or after exercise, findings in this area were inconclusive due to low event rates. Comparing the 2 groups’ dropout rates (early leaving of the study), 12% of exercisers and 11% of control participants dropped out. Pooled analysis resulted in a moderate-quality risk ratio for all-cause withdrawals with similar rates across groups (19 studies; 1,065 participants; risk ratio 1.02).

Long-term effects were analysed as very low-quality evidence (in 8 studies) with improvement in quality of life, fatigue, and physical function that persisted for 6 to 52 weeks post intervention though withdrawals, and adverse events were not measured in these studies.

Thus, it is uncertain (because of very low quality evidence) whether mixed exercise improved the quality of life and physical function or decreased the symptoms, compared to non-exercise (no intervention/wait list) or other exercise programs. Also, the interventions were heterogeneous; results often were based on small single studies, and adverse events were not measured.  

Authors’ conclusion

Mixed exercise may improve quality of life and the ability to do daily activities, and it may decrease pain or tiredness. Low-quality evidence suggested that mixed exercise may slightly improve stiffness. Reviewers considered the quality of evidence to be low to moderate because of small numbers of participants in the studies, some issues involving study design, and the low quality of results reported in the studies. Due to scarce data of adverse effects or harms, the uncertainty regarding safety prevails.

What next?

Further studies need to assess the impact of mixed-exercise training in adults with fibromyalgia and to investigate participants of different ages, ethnicities, and countries. These studies should be well-designed, adequately powered randomised trials that observe and report the outcomes describing baseline physical fitness levels, physical activity participation, exercise frequency, intensity, time (duration), type (mode), and progression with adverse-effects that matter most to patients, clinicians, and policymakers.