Subclassifying chronic fatigue syndrome through exercise testing.

  title={Subclassifying chronic fatigue syndrome through exercise testing.},
  author={J Mark VanNess and Christopher R. Snell and David R. Strayer and Line Dempsey and Staci R. Stevens},
  journal={Medicine and science in sports and exercise},
  volume={35 6},
PURPOSE The purpose of this study was to examine physiological responses of persons with chronic fatigue syndrome (CFS) to a graded exercise test. METHODS Cardiopulmonary exercise tests were performed on 189 patients diagnosed with CFS. Based on values for peak oxygen consumption, patients were assigned to one of four impairment categories (none, mild, moderate, and severe), using American Medical Association (AMA) guidelines. A one-way MANOVA was used to determine differences between… 

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Properties of measurements obtained during cardiopulmonary exercise testing in individuals with myalgic encephalomyelitis/chronic fatigue syndrome.

CPET measurements demonstrate adequate responsiveness and reproducibility for research and clinical applications and demonstrated moderate to high reliability for individuals with ME/CFS.

Discriminative Validity of Metabolic and Workload Measurements for Identifying People With Chronic Fatigue Syndrome

It might be concluded that a single exercise test is insufficient to reliably demonstrate functional impairment in people with CFS and a second test might be necessary to document the atypical recovery response and protracted fatigue possibly unique to CFS, which can severely limit productivity in the home and workplace.

Diminished Cardiopulmonary Capacity During Post-Exertional Malaise

AbstractReduced functional capacity and post-exertional malaise following physical activity are hallmark symptoms of Chronic Fatigue Syndrome (CFS). That these symptoms are often delayed may explain

Exercise capacity and immune function in male and female patients with chronic fatigue syndrome (CFS).

The results implicate abnormal immune activity in the pathology of exercise intolerance in CFS and are consistent with a channelopathy involving oxidative stress and nitric oxide-related toxicity.

Decreased oxygen extraction during cardiopulmonary exercise test in patients with chronic fatigue syndrome

Low oxygen uptake by muscle cells causes exercise intolerance in a majority of CFS patients, indicating insufficient metabolic adaptation to incremental exercise, and the high increase of the cardiac output relative to the increase of oxygen uptake argues against deconditioning as a cause for physical impairment in these patients.

Physiological Responses to Arm and Leg Exercise in Women Patients with Chronic Fatigue Syndrome

Cardiopulmonary exercise testing is a valid procedure for determining functional capacity in patients with CFS and the majority of values achieved at peak exhaustive exercise were significantly lower in CFS patients than controls.

Chronotropic Intolerance: An Overlooked Determinant of Symptoms and Activity Limitation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome?

The purposes of this review are to define CI and discuss its applications to clinical populations, summarize existing data regarding heart rate responses to exercise obtained during maximal CPET in people with ME/CFS, and discuss how trends related to CI observed in the literature should influence future patho-etiological research designs and clinical practice.

Cardiopulmonary Exercise Test Methodology for Assessing Exertion Intolerance in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Evidence to date indicates that ME/CFS patients are uniquely unable to reproduce CPET measures during a second test, despite giving maximal effort during both tests, due to the effects of PEM on energy production.

Physiological factors limiting exercise performance in CFS.

  • T. Noakes
  • Psychology
    Medicine and science in sports and exercise
  • 2004
Vanness et al. (8) propose that persons with chronic fatigue syndrome (CFS) can be classified into different categories according to their V̇O2max values. Since subjects with “mild” to “severe” CFS

Post-exertional symptoms distinguish myalgic encephalomyelitis/chronic fatigue syndrome subjects from healthy controls.

A standardized exertional stimulus produced prolonged, diverse symptoms in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome subjects, providing clues to the underlying pathophysiology of ME/CFS, leading to improved diagnosis and treatment.



Physiological responses to incremental exercise in patients with chronic fatigue syndrome.

It was found that the primary exercise-related physiological difference between the CFS and the control group was their significantly lower heart rate at any equal relative and at maximal work level.

Exercise capacity in chronic fatigue syndrome.

Reaching the age-predicted target heart rate seemed to be a limiting factor of the patients with CFS in achieving maximal effort, which could be due to autonomic disturbances.

Assessment of Functional Impairment by Cardiopulmonary Exercise Testing in Patients with Chronic Fatigue Syndrome

The highest V02 of any of the patients in this study was 29.5 ml/kg/min, very close to what normative data predicts to be the average maximal value for the entire group.

Aerobic work capacity in patients with chronic fatigue syndrome.

Patients with the chronic fatigue syndrome have reduced aerobic work capacity compared with normal subjects and patients with the irritable bowel syndrome and have an altered perception of their degree of exertion and their premorbid level of physical activity.

Metabolic and cardiovascular effects of a progressive exercise test in patients with chronic fatigue syndrome.

Impaired oxygen delivery to muscle in chronic fatigue syndrome.

Oxygen delivery was reduced in CFS patients compared with that in sedentary controls, and a significant correlation was found between oxidative metabolism and recovery of oxygen delivery.

Muscle histopathology and physiology in chronic fatigue syndrome.

There was no consistent correlation between symptoms and changes in fibre type prevalence, fibre size, degenerative or regenerative features, glycogen depletion, or mitochondrial abnormalities, and it is clear that CFS is not a myopathy.

The Chronic Fatigue Syndrome: A Comprehensive Approach to Its Definition and Study

We have developed a conceptual framework and a set of research guidelines for use in studies of the chronic fatigue syndrome. The guidelines cover the clinical and laboratory evaluation of persons

A community-based study of chronic fatigue syndrome.

Earlier findings suggesting that CFS is a syndrome primarily affecting white, middle-class patients were not supported, and the highest levels of CFS were consistently found among women, minority groups, and persons with lower levels of education and occupational status.

Chronic fatigue syndrome. 1: Etiology and pathogenesis.

An accurate case definition identifying homogeneous subtypes of CFS is needed and the integration of medical and psychologic treatment modalities and the use of both biologic and Psychologic markers to evaluate treatment response will enhance future treatment strategies.