Fig. 1

Line and scatter plot showing the median (interquartile range) levels of cytokines during microdialysis in the vastus lateralis muscle of the most painful leg in 24 patients with fibromyalgia (FMS) and 27 healthy controls (CON) before and after 15 weeks of resistance exercise twice per week. a IL-1β, b IL-6, c IL-8, d TNF. Microdialysis was performed for 220 min. During the first 140 min the participant rested (data not shown), whereafter they performed dynamic contractions of the leg (knee extension) for 20 min (EXC) followed by another 60 min of rest (recovery phase). Samples were collected every 20 min and the dialysate sampled between 120–140 min was regarded as baseline (BL). *P < 0.05, both sessions; ^# P < 0.05, only after resistance exercise. IL interleukin, TNF tumor necrosis factor beta