Resistance Exercise Lifts Fatigue in Fibromyalgia

“Person-centered” progressive resistance exercise boosted multiple aspects of fatigue in women with fibromyalgia, Swedish researcher reported.

In the substudy in a randomized controlled trial of muscle strength, health status, and pain intensity in 130 fibromyalgia patients (ages 22-64), the mean Multidimensional Fatigue Inventory-20 (MFI-20) improvements in the resistance group from baseline to post-treatment evaluation was 7.5% in general fatigue, 10.6% in physical fatigue, and 10.7% in mental fatigue, reported reported Anna Ericsson, PhD, of the University of Gothenburg in Goteborg, Sweden, and colleagues.

Working fewer hours and getting better sleep also improved fatigue in the 15-week multicenter study, they reported in Arthritis Research & Therapy.

“Significant improvements were found for change in the MFI-20 subscales for general fatigue, physical fatigue, and mental fatigue in the resistance exercise group in comparison with the active control group,” they noted.

The person-centered approach emphasizes active patient involvement in planning the treatment to enhance the patient’s ability to manage health problems, the authors explained.

Fibromyalgia affects approximately 1% to 3% of the general population, limiting work capacity and social life. While some research has suggested that physical exercise can lower fatigue levels, little is known about the specific effects of resistance exercise and in particular on fatigue.

Recruited through newspaper ads, the 130 patients were randomized to a resistance training group or an active control group receiving relaxation therapy. Those in the intervention arm worked out twice a week for 15 weeks in physiotherapy clinics, doing 50 minutes of resistance exercise targeting large muscle groups in the trunk and all four extremities. Initiated at 40% of one repetition maximum, training progressed to as much as 80% of one repetition maximum over 15 weeks.

More than 60% of participants increased loads up to 80% of one repetition maximum, and attendance was 71%. Only 7% of the resistance group dropped out because of increased pain, suggesting most women with fibromyalgia can tolerate tailored resistance exercise twice a week for over 3 months, the authors pointed out.

In other findings, the resistance exercise group improved in the Fibromyalgia Impact Questionnaire for fatigue from baseline to post-treatment assessment, with a mean difference of –8.6 (P=0.002). The resistance exercise group also improved in the Pittsburgh Sleep Quality Index (PSQI) subscale for sleep quality, with a mean difference of –0.2 (P=0.047). Active controls, however, showed PSQI subscale improvement in sleep medication needs, with a mean difference of 0.3 (P=0.036).

Sleep efficiency was the strongest predictor of change in the MFI-20 subscale for general fatigue (beta = -0.54, P=0.031, R²=0.05). Poorer sleep efficiency at baseline predicted improvement in general fatigue.

At baseline, the difference between the resistance exercise group and the active control group on the PSQI subscale of sleep efficiency was a mean 1.9 versus a mean of 1.4 (P=0.027). With adjustment for PSQI sleep efficiency, the difference between groups in fatigue change was significant only for the MFI-20 subscale of physical fatigue. Here the intervention group showed a score difference of –1.7 versus 0.0 for controls (P=0.013), for an effect size of 0.33.

Working fewer hours per week (beta=0.84, P=0.005) also emerged as significant independent predictors of change in physical fatigue (R²=0.14). Fewer hours worked at baseline also predicted improvement in physical fatigue.

A study limitation was that positive expectations of exercise have been found to influence the effect of exercise on psychological outcomes. In addition, the recruitment advertising could have attracted participants with expectations of improvement and a positive attitude toward resistance exercise, which in turn might have impacted compliance and the magnitude of improvement.

The authors noted that “person-centered approach … most likely contributed to the high attendance rate and low occurrence of adverse effects, as the approach enhances self-efficacy and sense of control in the participants.”

They also explained that active relaxation was chosen for the control group as it was assumed that it also would improve well-being in these patients.

• Reviewed by Henry A. Solomon, MD, FACP, FACCClinical Associate Professor, Weill Cornell Medical College and Dorothy Caputo, MA, BSN, RN, Nurse Planner

LAST UPDATED 08.18.2016

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