Comparison of physical and sedentary activities in CFS and their link to autonomic dysfunction

The MEA Ramsay Research Fund has been funding Professor Julia Newton and colleagues at the University of Newcastle to carry out a separate study into muscle abnormalities in ME/CFS. This study is now complete and the results are being prepared for publication.

Abstract published in QJM: an international journal of medicine on 7 March 2011.

Physical activity intensity but not sedentary activity is reduced in chronic fatigue syndrome and is associated with autonomic regulation

1. J.L. Newton1,
2. J. Pairman1,
3. K. Hallsworth1,2,
4. S. Moore1,2,
5. T. Plötz3 and
6. M.I. Trenell1,2

+ Author Affiliations

From the 1UK National Institute for Health Research Biomedical Research Centre in Ageing & Age-related Disease, Institute for Ageing and Health, Newcastle University, Newcastle, UK, 2MRC Centre for Brain Ageing & Vitality, Newcastle University, Newcastle upon Tyne and 3School of Computing Science, Newcastle University, Newcastle upon Tyne, UK

1. Address correspondence to Prof. J.L. Newton, Institute for Ageing and Health, Newcastle University, Newcastle, NE2 4HH, UK. email:

* Received January 11, 2011.
* Revision received February 4, 2011.


Background: Chronic fatigue syndrome (CFS) is a common debilitating condition associated with reduced function and impaired quality of life. The cause is unknown and treatments limited. Studies confirm that CFS is associated with impaired autonomic regulation and impaired muscle function.

Aim: Define the relationship between sedentary behaviour, physical activity and autonomic regulation in people with CFS.

Design: Cohort study.

Methods: Physical activity was assessed objectively in 107 CFS patients (Fukuda) and age, sex and body mass index (BMI)-matched sedentary controls (n = 107). Fatigue severity was determined using the Fatigue Impact Scale in all participants and heart rate variability performed in the CFS group.

The CFS group had levels and patterns of sedentary behaviour similar to non-fatigue controls (P  > 0.05). Seventy-nine percent of the CFS group did not achieve the WHO recommended 10 000 steps per day. Active energy expenditure [time >3 METs (metabolic equivalents)] was reduced in CFS when compared with controls (P < 0.0001). Physical activity duration was inversely associated with resting heart rate (P = 0.04; r2  = 0.03), with reduced activity significantly associating with reduced heart rate variability in CFS. There were no relationships between fatigue severity and any parameter of activity. Thirty-seven percent of the CFS group were overweight (BMI 25–29.9) and 20% obese (BMI ≥30). Conclusion: Low levels of physical activity reported in CFS represent a significant and potentially modifiable perpetuating factor in CFS and are not attributable to high levels of sedentary activity, rather a decrease in physical activity intensity. The reduction in physical activity can in part be explained by autonomic dysfunction but not fatigue severity.

* © The Author 2011. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email:


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