Preference for Resistance Training Volume After Acute Exercise in Women With Fibromyalgia: A Randomized Crossover Clinical Trial.

Abstract

Background and purpose: To evaluate participants' preferences following acute exposure to three resistance training protocols differing solely in the number of sets performed.

Methods: Randomized crossover clinical trial. Thirty-eight women aged 18-65 years with fibromyalgia diagnosed according to the 2016 American College of Rheumatology criteria completed the study. All participants were naïve to resistance training during the previous 6 months and completed every intervention protocol and assessment. Participants performed three resistance training sessions in randomized order, consisting of one-, two-, or three-set protocols separated by 7-day washout periods. Exercise selection, intensity, and repetitions were standardized across protocols, with the number of sets representing the only intervention variable. The primary outcome was participant preference for resistance training volume after completion of all three protocols. Secondary outcomes included treatment expectancy, pain intensity assessed before and after exercise and 24 hours later, and exercise execution time.

Results: No participant selected the one-set protocol as the preferred training volume, whereas the two- and three-set protocols were equally preferred, each being selected by 50% of participants (p < 0.001; Cohen's w = 0.71). Treatment expectancy did not differ significantly among protocols (p = 0.20). No between-protocol differences in pain intensity were observed at any assessment time point. A significant within-protocol reduction in pain over time was identified only for the two-set protocol (p = 0.015); however, the magnitude of change did not reach the predefined minimal clinically important difference. Exercise execution time did not differ significantly among training volumes, and no serious adverse events occurred during the study.

Discussion: Women with fibromyalgia demonstrated equivalent preference for resistance training protocols involving two and three sets, whereas no participant identified the one-set protocol as the preferred option. Treatment expectancy was similar across protocols, and no clinically meaningful differences in pain intensity were observed. These findings support the incorporation of patient preference into individualized resistance training prescriptions and warrant further investigation of whether such preferences translate into improved long-term adherence and clinical outcomes.

Trial registration: ClinicalTrials.gov (Identifier: NCT06424743, 2024-08-21).