Can exercise limits prevent post-exertional malaise in chronic fatigue syndrome

Clin Rehabil. 2008 May;22(5):426-35.

Can exercise limits prevent post-exertional malaise in chronic fatigue syndrome? An uncontrolled clinical trial.

Nijs J, Almond F, De Becker P, Truijen S, Paul L. Department of Human Physiology, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel. This email address is being protected from spambots. You need JavaScript enabled to view it..

Objective: It was hypothesized that the use of exercise limits prevents symptom increases and worsening of their health status following a walking exercise in people with chronic fatigue syndrome.

Design: An uncontrolled clinical trial (semi-experimental design).Setting: Outpatient clinic of a university department.Subjects: Twenty-four patients with chronic fatigue syndrome.

Interventions: Subjects undertook a walking test with the two concurrent exercise limits. Each subject walked at an intensity where the maximum heart rate was determined by heart rate corresponding to the respiratory exchange ratio = 1.0 derived from a previous submaximal exercise test and for a duration calculated from how long each patient felt they were able to walk.

Main outcome measures: The Short Form 36 Health Survey or SF-36, the Chronic Fatigue Syndrome Symptom List, and the Chronic Fatigue Syndrome - Activities and Participation Questionnaire were filled in prior to, immediately after and 24 hours after exercise.

Results: The fatigue increase observed immediately post-exercise (P= 0.006) returned to pre-exercise levels 24 hours post-exercise. The increase in pain observed immediately post-exercise was retained at 24 hours post-exercise (P=0.03). Fourteen of the 24 subjects experienced a clinically meaningful change in bodily pain (change of SF-36 bodily pain score >/=10); 6 indicated that the exercise bout had slightly worsened their health status, and 2 had a clinically meaningful decrease in vitality (change of SF-36 vitality score >/=20). There was no change in activity limitations/participation restrictions.

Conclusion: It was shown that the use of exercise limits (limiting both the intensity and duration of exercise) prevents important health status changes following a walking exercise in people with chronic fatigue syndrome, but was unable to prevent short-term symptom increases.