Failure To Reproduce VO2max In Patients With Chronic Fatigue Syndrome As An Objective Indicator Of Disease

PURPOSE: To assess the reproducibility of VO2max in subjects diagnosed with chronic fatigue syndrome (CFS) compared to healthy controls. METHODS: Subjects were 10 females and 2 males (41.3+1.11 yrs) diagnosed with CFS by a physician experienced in the diagnosis of CFS, and 3 male and 4 female healthy controls (23.3+1.11 yrs) . Each subject completed two maximum exercise tests on a cycle ergometer separated by 24 hrs to assess the reproducibility of VO2max and associated measures. VO2max, max heart rate (HRmax), anaerobic threshold (AT), max workload (Wmax), workload at AT (ATwork), and respiratory exchange ratio (RER) were measured. RESULTS: For CFS subjects, significant decreases from test 1 to test 2 were 13.5% for VO2max (21.5 to 18.6 ml.kg-1.min-1; p