Patients with Fibromyalgia Shouldn’t Resist Resistance Training

Active rehabilitation with exercise has become a more common strategy for countering the effects of fibromyalgia, according to the investigators of a systematic review and meta-analysis looking at the benefits of resistance-based exercise in those with the disorder. Their findings were recently published in the Journal of Bodywork and Movement Therapies.

The investigators, from Australia, Brazil, and Portugal, say that resistance-based exercise has been emphasized either alone or in combination with aerobic or flexibility interventions because of its potential for pain modulation through promotion of neuromuscular adaptations that enhance physical function. Fibromyalgia, they note, is increasingly considered to have multidimensional effects on not only pain, but fatigue, psychological well-being, quality of life, and physical function. Multiple studies, the investigators say, have shown a moderate reduction in pain and improved physical function among patients with fibromyalgia who participate in a resistance-based exercise regimen.

Mining the literature for clues to a benefit

The current systematic review and meta-analysis included a search of 7 databases, conducted up to February 2024, which yielded 22 eligible randomized controlled trials involving 1235 participants.

The studies examined the effects on pain, fatigue, depression, anxiety, sleep quality, quality of life, physical function, and muscle strength in patients with fibromyalgia who underwent a resistance-based exercise program.

Patient demographics, along with clinical characteristics and exercise prescriptions, such as duration, number of sessions, and peak intensity, were also analyzed to determine whether they influenced outcomes. A 3-level mixed-effects meta-analysis and meta-regression were used to analyze outcomes.

Several symptoms are shown to improve

Compared to control groups, patients with fibromyalgia who followed a resistance-based exercise program saw a small but statistically significant improvement in a number of symptoms, including:

• pain (standardized mean difference [SMD] -0.40, 95% confidence interval [CI] -0.55 to -0.25; P<.001)
• fatigue (-0.48 SMD, 95% CI -0.69 to -0.26; P<.001)
• depression (-0.46 SMD, 95% CI -0.70 to -0.22; P<.001)
• anxiety (-0.31 SMD, 95% CI -0.43 to -0.19; P<.001).

Sleep quality and physical function also improved slightly in patients undergoing a resistance-based exercise program, and there was a large effect size in lower-limb muscle strength (1.17 SMD, 95% CI 0.89 to 1.44; P<.001). Subgroup analyses determined that age, body mass index, and illness duration did not affect the benefits of resistance-based exercise. No additional effects were observed when aerobic or flexibility exercises were included.

Where the study fell short

Limitations of the analysis include the high risk of bias in many of the included studies, tied to concern about the randomization process, outcomes measurement, and selection of the results reported. Publication bias was found in 3 of the 4 outcomes that were assessed, and a high risk of indirectness was noted as well.

The level of certainty of evidence about the benefits of resistance exercise was low to very low. In addition, all studies included only females, so the results can’t be generalized to the male population with fibromyalgia.

Finally, due to limited evidence, the analysis did not investigate the potential impact of demographic, clinical, and exercise prescription moderators on anxiety, sleep quality, physical function, and muscle strength.

A pair of the study’s authors weigh in

“Exercise programs involving resistance exercise may positively affect multiple symptoms of fibromyalgia, including pain, fatigue, depression, anxiety, sleep quality, quality of life, physical function, and muscle strength,” co-investigators Pedro Lopez, BSc, MSc, PhD, and Anderson Rech, PhD, told MedPage Today. “Although the effects were generally small and the certainty of evidence was limited, these benefits appeared to occur across different patient profiles and exercise prescriptions, suggesting that even low-dose, moderate-intensity resistance exercise may be useful when integrated into fibromyalgia care.”

“Resistance exercise,” they emphasized, “should be considered an important component of multidisciplinary fibromyalgia management.”

Drs. Lopez and Rech believe more studies with better study designs are needed. “Many randomized controlled trials in this field still have important methodological limitations, including high risk of bias, poor reporting of exercise prescription, limited control of intervention fidelity, and insufficient reporting of adherence, adverse events, and usual care,” they concluded.