NC and CFS subjects received 10 s heat stimuli to each forearm to characterize their heat
pain sensitivity at baseline and after handgrip exercises. Heat intensity increased from
baseline to target temperature in 6 s and was continued at this level for another 4 s. All
subjects rated the heat pain intensity at the end of each stimulus using a VAS (0-10). The
experimental pain ratings of 3 trials per arm were averaged
A: Average (SEM) heat pain ratings of 44°C heat stimuli to the
forearm were significantly greater in CFS subjects than NC (p = .005). However, within
each group there was no statistical difference between experimental pain ratings obtained
before and after handgrip exercise (p > .05).
B: Average (SEM) heat pain ratings of 46°C heat stimuli to the
forearm were significantly greater in CFS subjects than NC (p = .005). However,
experimental pain ratings obtained before and after handgrip exercise were not statistical
different within each group (p > .05).