Abstract
To examine the role of delay in recovery of peripheral muscle function following exercise in the fatigue experienced by patients with the chronic fatigue syndrome (CFS) and to examine the influence of effort perception in limiting exercise performance in these patients, a study was carried out on a group of twelve patients with chronic fatigue syndrome and 12 sex and age-matched sedentary control subjects. Symptom limited incremental cycle exercise tests including measurements of perceived exertion were performed followed by examination of the contractile properties of the quadriceps muscle group for up to 48 hours. Muscle function was assessed by percutaneous electrical stimulation and maximum voluntary contractions. Muscle function at rest and during recovery was normal in CFS patients as assessed by maximum isometric voluntary contraction, 20:50 Hz tetanic force ratio and maximum relaxation rate. Exercise duration and the relationship between heart rate and work rate during exercise were similar in both groups. CFS patients had higher perceived exertion scores in relation to heart rate during exercise representing a reduced effort sensation threshold of 3.2 units on an unmodified Borg scale in CFS patients. Patients with chronic fatigue syndrome show normal muscle physiology before and after exercise. Raised perceived exertion scores during exercise suggest that central factors are limiting exercise capacity in these patients.
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Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Behan P. O., Behan W. M., Bell E. J. The postviral fatigue syndrome--an analysis of the findings in 50 cases. J Infect. 1985 May;10(3):211–222. doi: 10.1016/s0163-4453(85)92488-0. [DOI] [PubMed] [Google Scholar]
- Behan W. M., More I. A., Behan P. O. Mitochondrial abnormalities in the postviral fatigue syndrome. Acta Neuropathol. 1991;83(1):61–65. doi: 10.1007/BF00294431. [DOI] [PubMed] [Google Scholar]
- Borg G. Perceived exertion as an indicator of somatic stress. Scand J Rehabil Med. 1970;2(2):92–98. [PubMed] [Google Scholar]
- Cooper R. G., Edwards R. H., Gibson H., Stokes M. J. Human muscle fatigue: frequency dependence of excitation and force generation. J Physiol. 1988 Mar;397:585–599. doi: 10.1113/jphysiol.1988.sp017020. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Edwards R. H., Gibson H., Clague J. E., Helliwell T. Muscle histopathology and physiology in chronic fatigue syndrome. Ciba Found Symp. 1993;173:102–131. doi: 10.1002/9780470514382.ch7. [DOI] [PubMed] [Google Scholar]
- Edwards R. H., Hill D. K., Jones D. A., Merton P. A. Fatigue of long duration in human skeletal muscle after exercise. J Physiol. 1977 Nov;272(3):769–778. doi: 10.1113/jphysiol.1977.sp012072. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Edwards R. H., Melcher A., Hesser C. M., Wigertz O., Ekelund L. G. Physiological correlates of perceived exertion in continuous and intermittent exercise with the same average power output. Eur J Clin Invest. 1972 Jan;2(2):108–114. doi: 10.1111/j.1365-2362.1972.tb00578.x. [DOI] [PubMed] [Google Scholar]
- Edwards R. H. Muscle fatigue and pain. Acta Med Scand Suppl. 1986;711:179–188. doi: 10.1111/j.0954-6820.1986.tb08948.x. [DOI] [PubMed] [Google Scholar]
- Edwards R. H. Studies of muscular performance in normal and dystrophic subjects. Br Med Bull. 1980 May;36(2):159–164. doi: 10.1093/oxfordjournals.bmb.a071632. [DOI] [PubMed] [Google Scholar]
- Edwards R. H., Young A., Hosking G. P., Jones D. A. Human skeletal muscle function: description of tests and normal values. Clin Sci Mol Med. 1977 Mar;52(3):283–290. doi: 10.1042/cs0520283. [DOI] [PubMed] [Google Scholar]
- Gandevia S. C., McCloskey D. I. Interpretation of perceived motor commands by reference to afferent signals. J Physiol. 1978 Oct;283:493–499. [PMC free article] [PubMed] [Google Scholar]
- Gow J. W., Behan W. M., Clements G. B., Woodall C., Riding M., Behan P. O. Enteroviral RNA sequences detected by polymerase chain reaction in muscle of patients with postviral fatigue syndrome. BMJ. 1991 Mar 23;302(6778):692–696. doi: 10.1136/bmj.302.6778.692. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Holmes G. P., Kaplan J. E., Gantz N. M., Komaroff A. L., Schonberger L. B., Straus S. E., Jones J. F., Dubois R. E., Cunningham-Rundles C., Pahwa S. Chronic fatigue syndrome: a working case definition. Ann Intern Med. 1988 Mar;108(3):387–389. doi: 10.7326/0003-4819-108-3-387. [DOI] [PubMed] [Google Scholar]
- Jamal G. A., Hansen S. Electrophysiological studies in the post-viral fatigue syndrome. J Neurol Neurosurg Psychiatry. 1985 Jul;48(7):691–694. doi: 10.1136/jnnp.48.7.691. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lloyd A. R., Gandevia S. C., Hales J. P. Muscle performance, voluntary activation, twitch properties and perceived effort in normal subjects and patients with the chronic fatigue syndrome. Brain. 1991 Feb;114(Pt 1A):85–98. [PubMed] [Google Scholar]
- Lloyd A. R., Hales J. P., Gandevia S. C. Muscle strength, endurance and recovery in the post-infection fatigue syndrome. J Neurol Neurosurg Psychiatry. 1988 Oct;51(10):1316–1322. doi: 10.1136/jnnp.51.10.1316. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Montague T. J., Marrie T. J., Klassen G. A., Bewick D. J., Horacek B. M. Cardiac function at rest and with exercise in the chronic fatigue syndrome. Chest. 1989 Apr;95(4):779–784. doi: 10.1378/chest.95.4.779. [DOI] [PubMed] [Google Scholar]
- Newham D. J., Mills K. R., Quigley B. M., Edwards R. H. Pain and fatigue after concentric and eccentric muscle contractions. Clin Sci (Lond) 1983 Jan;64(1):55–62. doi: 10.1042/cs0640055. [DOI] [PubMed] [Google Scholar]
- Newham D. J., Mills K. R., Quigley B. M., Edwards R. H. Pain and fatigue after concentric and eccentric muscle contractions. Clin Sci (Lond) 1983 Jan;64(1):55–62. doi: 10.1042/cs0640055. [DOI] [PubMed] [Google Scholar]
- Peel M. Rehabilitation in postviral syndrome. J Soc Occup Med. 1988 Spring-Summer;38(1-2):44–45. doi: 10.1093/occmed/38.1-2.44. [DOI] [PubMed] [Google Scholar]
- Riley M. S., O'Brien C. J., McCluskey D. R., Bell N. P., Nicholls D. P. Aerobic work capacity in patients with chronic fatigue syndrome. BMJ. 1990 Oct 27;301(6758):953–956. doi: 10.1136/bmj.301.6758.953. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rutherford O. M., Jones D. A., Newham D. J. Clinical and experimental application of the percutaneous twitch superimposition technique for the study of human muscle activation. J Neurol Neurosurg Psychiatry. 1986 Nov;49(11):1288–1291. doi: 10.1136/jnnp.49.11.1288. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stokes M. J., Cooper R. G., Edwards R. H. Normal muscle strength and fatigability in patients with effort syndromes. BMJ. 1988 Oct 22;297(6655):1014–1017. doi: 10.1136/bmj.297.6655.1014. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stokes M., Young A. The contribution of reflex inhibition to arthrogenous muscle weakness. Clin Sci (Lond) 1984 Jul;67(1):7–14. doi: 10.1042/cs0670007. [DOI] [PubMed] [Google Scholar]
- Woods J. J., Furbush F., Bigland-Ritchie B. Evidence for a fatigue-induced reflex inhibition of motoneuron firing rates. J Neurophysiol. 1987 Jul;58(1):125–137. doi: 10.1152/jn.1987.58.1.125. [DOI] [PubMed] [Google Scholar]