تاثیر تست ورزش حداکثر بر علائم و فعالیت در سندرم خستگی مزمن

Objective This study examined the effects of exercise on symptoms and activity in chronic fatigue syndrome (CFS). Methods Twenty CFS patients and 20 neighborhood controls performed an incremental exercise test until exhaustion. Fatigue, muscle pain, minutes spent resting, and the level of physical activity were assessed with a self-observation list. Physical activity was assessed with an actometer as well. Data were obtained 3 days before the maximal exercise test (MET) up to 5 days thereafter. Results For CFS patients, daily observed fatigue was increased up to 2 days after the exercise test. For controls, self-observed fatigue returned to baseline after 2 h. Both CFS patients and controls spent more minutes resting on the day before and on the day after the MET. For CFS patients, self-observed minutes resting increased on the day of the exercise test. For neither group, a decrease of actometer recorded or self-observed physical activity after exercise was found. Conclusion Fatigue in CFS patients increased after exercise, but the level of actual physical activity remained unchanged.

Chronic fatigue syndrome (CFS) is characterized by a severe, disabling, and unexplained fatigue, lasting for at least 6 months. CFS patients often report that even minimal exercise aggravates symptoms and leads to a decrease of physical activity [1]. Nevertheless, in several studies, gradually increasing activity programs have proven to be important in the treatment of CFS [2], [3], [4], [5], [6] and [7]. Although CFS patients seem to have the belief that activity is harmful, the effect of exercise on symptoms and activity in CFS patients is not known. Until now, only a few studies examined exacerbation of symptoms and decrease of physical activity after exercise. Most of these studies mainly concern physiological responses to treadmill or cycle exercise tests in CFS. Two uncontrolled studies, one measuring on the seventh day after exercise [8] and one everyday up to 7 days [9], did not find any adverse effects of exercise on symptoms and activity. Conversely, two controlled studies did find an increase of fatigue after exercise. One study measured after 24 h [10], 1 up to 4 days [11]. In the studies mentioned, assessment took place by just asking for adverse after-effects following testing [8], by questionnaires like the modified version of the Profile Of Mood Scales (POMS; [9], [10] and [11]), an activity restriction index [9], a symptom log [9], and daily ratings of fatigue [11]. Only in one study was an accelerometer used to measure the effect of exercise on physical activity. An unexplained reduction in activity on the fifth day after the exercise test was found for CFS but not for controls [12]. It has been shown that self-report questionnaires on physical activity do not correlate very well with accelerometer readings [13]. Whereas questionnaires that require simple ratings of actual activity were related to the accelerometer, instruments that require general subjective interpretations of activity were not. Furthermore, questionnaires like the POMS do not seem sensitive for day-to-day changes in repeated measurements. Standardized self-observation measures seem more appropriate to assess fluctuations in fatigue [14] and [15]. The purpose of the current study was to investigate the effect of a maximal exercise test (MET) on fatigue, muscle pain, rest, and activity on the days surrounding the exercise test. In a former study [16], the physiological aspects of a MET in CFS compared with controls were described. No significant differences in physical fitness between CFS patients and their controls were found. In this same study, self-observation measurements, as well as an accelerometer, were used. These results are presented now. Symptoms and activity were measured the hours before and after the test, as well as the days before, of, and after the exercise test. CFS patients were compared with neighborhood controls. It was expected that after the MET for CFS patients, as well as for controls fatigue, muscle pain and rest will be increased and physical activity will be decreased as compared with baseline. In this context, a significant difference in the extent as well as in the duration of changes in symptoms and activity between CFS and controls was anticipated. CFS patients were expected to experience a more severe increase of symptoms, of longer duration, and a more prevalent and longer lasting decrease of activity.