Fibromyalgia (FM) is an idiopathic disease characterized by widespread pain and a myriad of symptoms. Symptoms are diverse and include not only pain but also anxiety, depression, orthostatic intolerance, and cold intolerance. While the etiology of FM is not fully understood, data have suggested that FM may stem from dysfunction of the autonomic nervous system. This dysfunction has been reported at rest, and after a physiological stressor such as exercise. However, few studies have examined the responses during exercise. This novel approach may shed some new light on the effect of exercise in women with FM.