To evaluate the efficacy of aerobic exercise in reducing the pain intensity and functional status in patients with fibromyalgia, and to determine the dose-response relationship, specifically identifying the optimal dose for maximum clinical benefits.
This systematic review and meta-analysis included a search of PubMed, PEDro, Google Scholar, and EBSCO for randomized controlled trials (RCTs) of aerobic exercise in patients with clinical diagnosis of fibromyalgia on pain intensity (Visual Analog Scale) and clinical/functional status (Fibromyalgia Impact Questionnaire, FIQ) from inception to 9 February 2024. Two independent investigators selected the studies, extracted the data, and assessed the risk of bias (using the Cochrane Risk of Bias Tool 2.0) and certainty of evidence (using the GRADE approach). The dose-response relationship was evaluated using a restricted cubic spline model.
Twenty-three RCTs were included. The meta-analysis showed a significant improvement in pain intensity and functional status. A minimum dose of 50 minutes per week (SMD: -0.67, 95%CI: -0.70 to -0.65) and a total duration of 600 minutes (SMD: -0.65, 95% CI = -0.69 to -0.62) was estimated to effectively reduce pain intensity. The maximum effect was achieved with 90 minutes per week (SMD: -1.14, 95%CI = -1.19 to -1.09) and 1200 minutes total duration (SMD: -1.08, 95%CI = -1.13 to -1.02). Additionally, a minimum dose of 60 minutes per week (SMD: -0.66; 95%CI: -0.62 to -0.70) and 900 minutes total duration (SMD: -0.64; 95%CI: -0.60 to -0.68) was estimated to effectively reduce the FIQ. While the maximum effect was obtained with 150 minutes per week (SMD: -1.65; 95%CI: -1.78 to -1.53) and 3000 minutes of total duration (SMD: -1.36; 95%CI: -1.48 to -1.24).
The results of the meta-analysis showed that aerobic exercise is effective in reducing both the pain and clinical/functional status in patients with fibromyalgia. Specifically, a maximal effect on pain intensity was observed at 90 minutes per week and at 1200 total time (min) of exercise during the entire program. In addition, a linear dose-response association of both weekly minutes and total minutes of aerobic exercise with the reduction in the FIQ was observed, with a minimum dose of 60 minutes per week and 900 total minutes being necessary to obtain a moderate effect. However, the certainty of the evidence was low due to the limitations of the design of the included studies.
The findings are of importance in the context of public health. But, given the difficulty in meeting international physical activity recommendations for patients with fibromyalgia, an individual exercise prescription that gradually progresses them up to those recommendations (i.e., 90 min daily of light-to- moderate physical activity) would seem appropriate.
Exercise
Dose–response relationship
