Strength and physiological response to exercise in patients with chronic fatigue syndrome

Abstract

Objective-To measure strength, aerobic exercise capacity and eYciency, and functional incapacity in patients with chronic fatigue syndrome (CFS) who do not have a current psychiatric disorder. Methods-Sixty six patients with CFS without a current psychiatric disorder, 30 healthy but sedentary controls, and 15 patients with a current major depressive disorder were recruited into the study. Exercise capacity and eYciency were assessed by monitoring peak and submaximal oxygen uptake, heart rate, blood lactate, duration of exercise, and perceived exertion during a treadmill walking test. Strength was measured using twitch interpolated voluntary isometric quadriceps contractions. Symptomatic measures included physical and mental fatigue, mood, sleep, somatic amplification, and functional incapacity. Results-Compared with sedentary controls, patients with CFS were physically weaker, had a significantly reduced exercise capacity, and perceived greater eVort during exercise, but were equally unfit. Compared with depressed controls, patients with CFS had significantly higher submaximal oxygen uptakes during exercise, were weaker, and perceived greater physical fatigue and incapacity. Multiple regression models suggested that exercise incapacity in CFS was related to quadriceps muscle weakness, increased cardiovascular response to exercise, and body mass index. The best model of the increased exercise capacity found after graded exercise therapy consisted of a reduction in submaximal heart rate response to exercise. Conclusions-Patients with CFS were weaker than sedentary and depressed controls and as unfit as sedentary controls. Low exercise capacity in patients with CFS was related to quadriceps muscle weakness, low physical fitness, and a high body mass ratio. Improved physical fitness after treatment was associated with increased exercise capacity. These data imply that physical deconditioning helps to maintain physical disability in CFS and that a treatment designed to reverse deconditioning helps to improve physical function. (J Neurol Neurosurg Psychiatry 2000;69:302-307)

Differential heat shock protein responses to strenuous standardized exercise in chronic fatigue syndrome patients and matched healthy controls

“…18 In particular, an enhanced activity of oxidative stress has been demonstrated in resting CFS patients and post-exercise. [18][19][20] Thus, impairment of mitochondrial oxidative phosphorylation and antioxidant defences have been implicated in the pathogenesis of CFS. 18;21 In the current study, differences were observed in the expression of HSP27 by CFS patients compared with control subjects, both in basal expression and following strenuous exercise.…”

Timed loaded standing in female chronic fatigue syndrome compared with other populations

“…Both deconditioning and central factors have been used to explain this muscular weakness in CFS [23][24].…”

A Cross-Cultural Perspective on Psychological Determinants of Chronic Fatigue Syndrome: a Comparison Between a Portuguese and a Dutch Patient Sample

“…Patients' perceptions and expectations related to symptom exacerbation as a consequence of exercise can explain the reduced levels of physical activity found in these patients [6]. At the same time, lack of physical activity and excessive resting are factors that can result in physical deconditioning which, in turn, might perpetuate fatigue and physical disability [19]. The importance of identifying and understanding the specific cognitive and behavioral determinants of CFS is reinforced by the promising results of CBT and graded exercise approaches in CFS management [20,21].…”