TENS for Movement-Evoked Pain in Fibromyalgia: A Randomised Double-Blind Controlled Trial

Purpose: Fibromyalgia involves chronic widespread pain and heightened movement evoked pain (MEP), which can limit access to resistance training's functional and psychological benefits by hindering exercise participation and adherence. This study aimed to determine whether transcutaneous electrical nerve stimulation (TENS) applied during resistance exercise reduces MEP in women with fibromyalgia. Materials and methods: 21 women with fibromyalgia performed 2 sets of 10 leg press repetitions at 60% predicted 1 RM while receiving randomized active TENS (100 Hz) or sham TENS. Pain intensity and unpleasantness (0 to 10 numerical rating scales) were assessed at baseline, immediately post exercise, 15 min post-exercise, end-of-day, and 24h later. Results: Active TENS led to a greater reduction in post-exercise pain than sham, with 90% of participants experiencing at least a 15% decrease in whole body pain 15 minutes post-exercise, compared to none in the sham group. No group differences were observed at the end of the day or 24h after the exercise session. Conclusion: These results suggest that a single session of high frequency TENS during resistance exercise can produce short term reductions in MEP in women with fibromyalgia. While effects did not persist at 24h, these short-term effects may help mitigate acute exercise related pain and support early training adherence.