Oxygen uptake during exercise in patients with primary fibromyalgia syndrome

Objective. Muscle ischemia has been postulated as a causative factor in pain and disability in patients with prunary fibromyalgia syndrome (PFS) and previous studies have demonstrated that patients with PFS have reduced maximum oxygen uptake (VO 2 ). Our objective was to examine the level and pattern of VO 2 in response to graded exercise and defined levels of constant work rate exercise in patients with PFS. Methods. Unmedicated patients fulfilling modified Yunus' criteria for the diagnosis of PFS and healthy control subjects performed upright cycle ergometry exercise with measurements of respiratory gas exchange and grading of pain using visual analog scores