Exercise as it relates to Disease/Does resistance training improve muscle strength and pain intensity in Fibromyalgia?

This page is a critical analysis of the research article "Resistance Exercise Improves Muscle Strength, Health Status and Pain Intensity in Fibromyalgia - a Randomised Controlled Trial" by Larsson A, Palstam A, Löfgren M, Ernberg M, Bjersing J, Bileviciute-Ljungar I et al.

What is the background to this research?
Fibromyalgia (FM) is a rheumatic, chronic, widespread pain condition, causing stiffness and tenderness of the muscles, tendons and joints. Fibromyalgia affects approximately 1-3% of the general population, and is more commonly identified in older women.



An association between physical activity - in particular resistance training - and the improvement of muscular strength and pain intensity in patients with fibromyalgia has been explored and analysed by a number of studies. Although the precise aetiology of FM is unknown, physical deconditioning is believed to contribute to the development of fibromyalgia. Current guidelines for patients with FM recommend standard aerobic exercise such as brisk walking and cycling. However, a few studies have documented promising effects of the embodiment of resistance training to increase muscle strength in patients with FM, as well as avoid an increase in the susceptibility of mechanical strain. A prompt diagnosis and treatment of fibromyalgia patients may produce substantial improvement in quality of life.

Where is the research from?
The research was conducted and completed in Sweden and was primarily supported by the Swedish Rheumatism Association. This article was published in the Arthritis Research & Therapy journal which is an international, open access, peer-reviewed journal. The lead author, Anette Larsson is a reputable expert within the Department of Rheumatology and Inflammation Research. She is respected for her research on fibromyalgia and the impact of physical activity on muscle conditioning and inflammatory cell control studies. The authors declare that they have no competing interests.

What kind of research was this?
This research was an assessor blinded randomised controlled multi-center trial (RCT). RCTs are the most stringent way of determining whether a cause-effect relation exists between the intervention and the outcome. The subjects within this study were placed in either a progressive resistance group exercise or an active control group. Additionally, a person-centred model of exercise was used to support the participants’ self-confidence for management of exercise. According to a report on the “levels of evidence” conducted by the Canadian Task Force on the Periodic Health Examination in 1979, RCTs were given the highest level because they are designed to be unbiased and have less risk of systematic errors.

What did the research involve?
A number of inclusion/exclusion criteria were determined and exhibited below in Table 1.

A total of 130 women were recruited for this and informed written consent was obtained from all participants before the baseline examination. The resistance exercise program was performed twice a week for 15 weeks and conducted on physiotherapy premises and at a local gym. An introductory discussion about the participants’ earlier experiences and instructions/modifications of specific exercises according to individual conditions and self-efficacy principles took place. An exercise protocol was created for each participant based on this information provided. Exercise focusing primarily on the lower extremity, core stability, and power were included in the program, and loads were increased only when the participant was ready to do so. The active control group was delivered similarly and performed as a series of mental exercises known as autogenic training. Participants spent 25 minutes focusing on relaxation and body awareness, followed by discussion and stretching.

The limitations of this study explored the biases of a small sample size of participants that possibly were already motivated to exercise, hence why they chose to participate. This was limited by blinding the participants in advance to which intervention was the control intervention or the active intervention. Additionally, a longer period of guidance and support was recommended to increase the possibilities of maintaining regular exercise habits.

What were the basic results?
Outcomes were assessed at baseline and at post-treatment examination after 15 weeks.

Primary outcomes:
 * Isometric knee-extension force: significantly greater improvement (p = 0.010). The effect size of change in isometric knee-extension force for the intervention group compared with the active control group was 0.55

Secondary outcomes:
 * The fibromyalgia impact questionnaire (FIQ): resistance exercise group improved significantly, demonstrating a lower score indicating a higher health status
 * 6 minute walk test (6MWT): significant improvement (p = 0.003) in the resistance exercise group compared to the active control group
 * Isometric elbow-flexion force: significantly greater improvement (p = 0.020) in the resistance group
 * Current pain intensity (VAS): Significantly greater improvement in current pain intensity (p = 0.033)
 * Health related quality of life (SF-36 PCS and MCS): Significant improvements within the resistance exercise group (p = 0.007). This was stated to be reflecting what is considered to be a clinically important difference.

What conclusions can we take from this research?
The positive results of the study showed that a supervised resistance exercise program based on person-centred principles with individually adjusted loads according to each participant’s resources, is feasible and successful. It was concluded that muscle-strengthening activity, such as resistance exercise, at least twice a week is recommended for preventing age-related loss of muscle mass and impaired physical function. These results prove positive outcomes of resistance training on patients with fibromyalgia; however, it can be difficult to obtain long-lasting effects following an intervention, as was stated by previous studies.

Practical advice / further resources
A possible reason for the paucity of studies evaluating the effects of resistance exercise in FM, is the risk of increased pain during isometric muscle contraction. If there is a possibility of pain during exercise, this may inhibit the participant to engage in physical activity, especially without the motivation and supervision of a health practitioner. Within the study, some of the reasons given by participants for not continuing to exercise were expensive gym memberships, need for continued supervision and guidance, and difficulties in prioritising exercise in daily life. Resistance exercising can be challenging and sometimes dangerous, therefore it is crucial that an individual exerts these exercises with the correct form and has a thorough understanding of loads, intensity, and repetitions. Furthermore, an unawareness of the psychological determinants that have an influence on motivation and maintenance of physical activity can be recognised in this study and may conflict with real-world implications.

Websites for FM exercising tips/advice
 * 1) https://fmaware.net/strength-training-for-the-person-with-fibromyalgia/
 * 2) https://arthritisaustralia.com.au/managing-arthritis/living-with-arthritis/physical-activity-and-exercise/exercise-and-fibromyalgia/

Support group information
 * 1) https://www.everydayhealth.com/fibromyalgia/resources/