Date sent:      	Fri, 4 Apr 2003 

Perceived Exertion in Fatiguing Illness: Civilians with Chronic Fatigue
Syndrome.

Med Sci Sports Exerc 2003 Apr;35(4):563-568

Cook DB [1, 2], Nagelkirk PR [1, 2], Peckerman A [1, 2], Poluri
A [2], Lamanca JJ [2, 3], Natelson BH [1, 2]


[1] Center for the Study of War-Related Illnesses, VA NJ Health Care,
East Orange, NJ;

[2] Chronic Fatigue Syndrome Cooperative Research Center, University of
Medicine and Dentistry of New Jersey - New Jersey Medical School, Newark,
NJ; and

[3] The Heart Failure Center, Division of Circulatory Physiology, New
York Presbyterian Hospital, New York, NY

Address for correspondence: Dane B. Cook, Ph.D., Fatigue Research Center,
New Jersey Medical School, 88 Ross Street, East Orange, NJ 07018; E-mail:
mailto:cookdb@njneuromed.org.

Submitted for publication January 2002.
Accepted for publication November 2002.

NLM Citation: PMID: 12673137


PURPOSE: It has been reported that ratings of perceived exertion (RPE)
are elevated in chronic fatigue syndrome (CFS). However, methodological
limitations have rendered this conclusion suspect. The purpose of the
present investigation was to examine RPE during exercise in civilians
with CFS by comparing subjects at both absolute exercise stage and
relative oxygen consumption reference criteria.

METHODS: A sample of 39 civilian females (N = 19 CFS, 34 +/- 7 yr; N = 20
healthy controls, 33 +/- 7 yr) underwent a maximal exercise test on a
treadmill. RPE were obtained during the last 15 s of each 3-min stage
using Borg's 6-20 scale.

RESULTS: There were no significant differences in peak [OV0312]O(2), RER,
or RPE. However, controls exercised longer (20.0 +/- 1.1 vs 15.9 +/- 1.1
min, P = 0.01, healthy vs CFS) and had higher peak HR (183 +/- 3 vs 174
+/- 2 bpm, P = 0.03, healthy vs CFS). Civilians with CFS reported higher
RPE at stages 3 through 5 compared with controls (F(3,111)= 3.6,P =
0.017). Preexercise fatigue ratings were not a significant predictor of
perceived exertion during exercise. There were no group differences
(F(1,37)= 1.9,P = 0.17) when RPE were expressed relative to peak
[OV0312]O(2).

CONCLUSIONS: Our results show that RPE are greater in civilians with CFS
when the data are expressed in terms of absolute exercise intensity.
However, by examining RPE relative to a common maximum (i.e., peak
[OV0312]O(2)) no differences were observed. The findings of the present
investigation challenge the notion that RPE are dysregulated in CFS.