METABOLIC AND CARDIOVASCULAR EFFECTS OF A PROGRESSIVE EXERCISE TEST IN PATIENTS WITH CHRONIC FATIGUE SYNDROME

PURPOSE: TO evaluate the aerobic power (as maximum volume of oxygen co nsumed [VO2 max]) of women with chronic fatigue syndrome (CFS). PATIEN TS AND METHODS: Twenty-one women with CFS and 22 sedentary healthy con trols (CON) were studied at the CFS Cooperative Research Center Exerci se Laboratory at the VA Medical Center, East Orange, New Jersey. Perfo rmance was measured on an incremental treadmill protocol walking to ex haustion. Expired gases were analyzed by a metabolic system, heart rat e was recorded continuously, and ratings of perceived exertion (RPE) w ere taken at each workload. The groups were divided into those who ach ieved VO2 max (CFS-MAX and CON-MAX) and those who stopped at a submaxi mal level (CFS-NOMAX and CON-NOMAX) by using standard criteria. RESULT S: Seventeen CON and 10 CFS subjects achieved VO2 max. The VO2 max (mL /kg/min) of the CFS-MAX (28.1 +/- 5.1) was lower than that of the CON- MAX (32.1 +/- 4.3, P = 0.05). The CFS-MAX achieved 98 +/- 11% of predi cted VO2 max. The CFS group had a higher RPE at the same absolute work loads as controls (P < 0.01) but not the same relative workloads. CONC LUSION: Compared with normal controls, women with CFS have an aerobic power indicating a low normal fitness level with no indication of card iopulmonary abnormality. Our CFS group could withstand a maximal tread mill exercise test without a major exacerbation in either fatigue or o ther symptoms of their illness.