Preprint Skeletal muscle properties in long COVID and ME/CFS differ from those induced by bed rest, 2025, Charlton, Wust et al

Google translation from Dutch to English,

https://www-amsterdamumc-org.transl...ensen.htm?_x_tr_sl=nl&_x_tr_tl=en&_x_tr_hl=en

May 27, 2025
Muscles of patients with post-covid and ME/CFS respond differently than those of healthy people
Fatigue and difficulty with exertion in people with post-covid and ME/CFS are not simply the result of poor fitness. This is evident from new research from Amsterdam UMC and the Vrije Universiteit Amsterdam. The changes in the muscles of these patients are different from those of healthy people who have been inactive for a long time. This must be taken into account in the treatment and rehabilitation of these patients.

In the study, researchers compared muscle changes in people with post-COVID and ME/CFS (myalgic encephalomyelitis/chronic fatigue syndrome) with those of healthy people who had been bedridden for 60 days. All groups had less energy than healthy people who were normally active and were less able to exert themselves. But the cause turned out to be different.

“Patients often hear that they are simply out of shape,” says exercise scientist and lead researcher Rob Wüst. “Our results show that this is not true. The changes in the muscles of these patients are different from what we see in healthy people who have been inactive for a long time.”

Key Findings
When comparing the muscles of the groups studied, remarkable differences emerged:

* No muscle breakdown in patients, while healthy people did have clear muscle loss (muscle atrophy) after bed rest
* Change in muscle fibers: patients had fewer 'slow' fibers that are needed for endurance, and more 'fast' fibers that tire quickly
* Problems with energy production in the muscles due to poorly functioning mitochondria - the energy factories of our cells
* Fewer capillaries in the muscles of ME/CFS patients, which may explain why they feel worse after exercise (post-exertional malaise)

Customized rehabilitation
These findings show that it is incorrect to assume that people with post-covid or ME/CFS mainly have complaints because they are less active. Their muscles work differently, and this must be taken into account in treatment and rehabilitation. The researchers therefore call for new, adapted rehabilitation programs that are more in line with what is really biologically going on in these patients.

The results of the study have not yet been assessed by fellow scientists, the so-called peer review. The study has already been published on the website MedRxiv , where scientists can publish their results early. Read the original message on the website of the VU .
Photo: Adobe Stock, generated with AI

Researchers
Research Institute

Read also

https://twitter.com/user/status/1927787768190525767
Click to expand...
 
Last edited:
Dolphin said:
No muscle breakdown in patients, while healthy people did have clear muscle loss (muscle atrophy) after bed rest
Click to expand...
That is interesting. When I was bedridden at least one doctor observed that I did not have any significant muscle wasting which was surprising given that I had been in bed for about 5 years at that point. (The dr I’m thinking of was doing was assessing for incapacity benefits l. I wasn’t sure if was insinuating that I might be exaggerating about my incapacity but the observation was valid.)


Dolphin said:
Customized rehabilitation
These findings show that it is incorrect to assume that people with post-covid or ME/CFS mainly have complaints because they are less active. Their muscles work differently, and this must be taken into account in treatment and rehabilitation. The researchers therefore call for new, adapted rehabilitation programs that are more in line with what is really biologically going on in these patients.
Click to expand...
Adapted rehabilitation programs??? I’m surprised if these authors believe that people with ME/CFS can be rehabilitated.
 
Robert 1973 said:
That is interesting. When I was bedridden at least one doctor observed that I did not have any significant muscle wasting which was surprising given that I had been in bed for about 5 years at that point.
Click to expand...
It certainly is.

One the most important and under appreciated clues about ME/CFS is that we are not much more (classically) deconditioned, and that we can be more active as soon as we feel better, without having to re-condition.

By all conventional understanding we should be much more deconditioned. Yet we are not. It is just not a basic or characteristic feature of most patients, and therefore not a defining one of ME/CFS, and so of little relevance to understanding or treating the primary pathological process driving the disease.

Why is that?
 
Last edited:
Sean said:
It certainly is.

One the most important and under appreciated clues about ME/CFS is that we are not much more (classically) deconditioned, and that we can be more active as soon as we feel better, without having to re-condition.

By all conventional understanding we should be much more deconditioned. Yet we are not. It is just is not a basic or characteristic feature of most patients, and therefore not a defining one of ME/CFS, and so of little relevance to understanding or treating the primary pathological process driving the disease.

Why is that?
Click to expand...
I would really like to know this because it's one of the rare consistent parts of my ME experience.
 
Sean said:
By all conventional understanding we should be much more deconditioned.
Click to expand...
Would an anti-deconditioning mechanism make sense as a survival trait? If a body does face situations where it is unable to move much (illness, hiberation, etc), the ability to emerge fully functional would boost survival. There might have been some crippling diseases in early history that made such a mechanism important, but further evolution came up with a better solution, leaving the mechanism mostly dormant and hidden. ME could be this ancient mechanism activating. Maybe there are some species that do show such an anti-deconditioning mechanism. How far back in evolution might this have occurred? Crocodilians? Probably not marine (too hard to hide safely for long periods).

There's my thinking out of the box for the day.
 
You must log in or register to reply here.
Back
Top