Tag: delayed recovery

Post-exertional malaise in daily life and experimental exercise models in patients with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Post-exertional malaise (PEM) is commonly recognized as a hallmark of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and is often used as one of several criteria for diagnosing ME/CFS.

In this perspective paper we want to reflect on how PEM is understood, assessed, and evaluated in scientific literature, and to identify topics to be addressed in future research.

Studies show that patients use a wide variety of words and concepts to label their experience of PEM in everyday life, and they report physical or mental exertions as triggers of PEM. They also report that PEM may have an immediate or delayed onset and may last from a few days to several months.

When standardized exercise tests are used to trigger PEM experimentally, the exacerbation of symptoms has a more immediate onset but still shows a wide variability in duration.

There are indications of altered muscular metabolism and autonomic nervous responses if exercise is repeated on successive days in patients with ME/CFS. The decreased muscular capacity appears to be maintained over several days following such controlled exercise bouts. These responses may correspond to patients’ experiences of increased exertion.

Based on this background we argue that there is a need to look more closely into the processes occurring in the restitution period following exercise, as PEM reaches the peak in this phase.

Source: Nina K. Vøllestad, Anne Marit Mengshoel. Post-exertional malaise in daily life and experimental exercise models in patients with myalgic encephalomyelitis/chronic fatigue syndrome. Frontiers in Physiology, Volume 14- 2023. https://www.frontiersin.org/articles/10.3389/fphys.2023.1257557/abstract

Demonstration of delayed recovery from fatiguing exercise in chronic fatigue syndrome

Abstract:

Patients with the chronic fatigue syndrome (CFS) complain consistently of delay in recovery of peripheral muscle function after exercise. The purpose of this study was to try to confirm this observation.

A fatiguing exercise test was carried out on the quadriceps muscle group of ten patients and ten control subjects. The test consisted of 18 maximum voluntary contractions (MVCs) with a 50% duty cycle (10 s contraction, 10 s rest), and the force generated by each contraction was recorded using a KinCom dynamometer. This was followed by a recovery phase lasting 200 min in which quadriceps strength was evaluated at increasing intervals, and a follow-up session at 24 h post-exercise involving three 10 s MVCs.

Throughout the exercise period, the MVCs obtained from the control group were significantly higher than those of the patient group (P = 0.006), but both groups showed a parallel decline in force over the 18 contractions, in keeping with a similar endurance capacity.

Recovery was prolonged in the patient group, however, with a significant difference compared to initial MVCs being evident during the recovery phase after exercise (P = 0.001) and also at 24 h (P < 0.001). In contrast, the control group achieved MVCs which were not significantly different from initial values during the recovery phase, and maintained these at 24 h.

These findings support the clinical complaint of delayed recovery after exercise in patients with CFS.

Copyright 1999 Lippincott Williams & Wilkins

 

Source: Paul L, Wood L, Behan WM, Maclaren WM. Demonstration of delayed recovery from fatiguing exercise in chronic fatigue syndrome. Eur J Neurol. 1999 Jan;6(1):63-9. http://www.ncbi.nlm.nih.gov/pubmed/10209352

 

Medical aspects of delayed convalescence

Abstract:

Disease and illness are not synonymous. In most instances, disease is demonstrable by anatomic, physiologic, biochemical, microbiologic, or immunologic abnormalities. Disease is a pathologic process. Not all persons with a disease are sick or ill. Symptoms of illness associated with a disease may be manifest or persist after the disease has disappeared.

The absence of demonstrable disease, however, does not necessarily mean that symptoms of illness are unreal. Recovery from disease and recovery from illness are not always equated. Many factors, including personal characteristics and social circumstances, can be responsible for recovery from disease and illness.

Chronic fatigue syndrome or symptoms of illness can persist in some patients but not in others after many different diseases.

 

Source: Cluff LE. Medical aspects of delayed convalescence. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S138-40.  http://www.ncbi.nlm.nih.gov/pubmed/2020799