Abstract Purpose To explore acute changes in laboratory-based indices of experimental pain modulation in women with fibromyalgia following two exercise modalities (strength training vs. walking) during the first and fourth weeks of an exercise program. Methods This exploratory quasi-experimental study employed a repeated measures design and was conducted as a secondary analysis of a registered clinical trial. Women diagnosed with fibromyalgia were allocated to either a walking or a strength training group. The walking group performed moderate-intensity treadmill walking (60–70% of estimated maximum heart rate) for 40 min, while the strength training group completed moderate-intensity resistance exercises prescribed at 50% of one-repetition maximum, determined using the 1-RM test. Laboratory-based measures of experimental pain sensitivity and endogenous pain modulation—including pressure pain thresholds, temporal summation, and conditioned pain modulation—were assessed before and after exercise sessions in the first and fourth weeks. Results 18 women with fibromyalgia and comparable baseline characteristics were evaluated. Between-group and within-group comparisons across time revealed no statistically detectable differences in experimental pain sensitivity or endogenous pain modulation indices ( p ≥ .05). Observed changes were small and accompanied by wide confidence intervals, reflecting substantial interindividual variability and the absence of consistent acute exercise-related patterns. Conclusion Neither walking nor strength training produced statistically detectable differences in laboratory-based measures of experimental pain modulation, including conditioned pain modulation and temporal summation.
Melo et al. (Fri,) studied this question.