Muscles of long Covid patients respond differently to inactivity than healthy people

The muscles of people who suffer from long Covid or the chronic illness ME/CVS respond differently to a workout after a period of inactivity than the muscles of people with a clean bill of health, a study by the Vrije Universities and Amsterdam UMC has proven. According to the researchers, this means that the fatigue and struggle among people with long Covid or ME/CVS does not come due to them being out of shape.

Movement scientists compared the muscle changes among people with these health issues to those of healthy people who had rested for 60 days. All groups were lacking in energy and were able to produce less effort. “But the cause proved to be different,” the Vrije Universiteit said.

For example, there is no muscle breakdown in patients, while healthy people did have a clear decrease in muscle after bed rest. There also appeared to be a change in the muscle fibers. “Patients had fewer “slow-twitch” fibers, which are essential for endurance, and more “fast-twitch” fibers, which tire quickly,” the researchers wrote.

Researchers also saw issues when it came to energy production. This came as a result of malfunctioning mitochondria, which are the energy factories of human cells.

Another reason that researchers believe that people who have had long Covid or ME/CVS felt worse after a workout was the fact that their muscles had fewer capillaries.

According to the researchers, the findings show that it is unfair to assume that people suffering from long Covid or ME/CVS are experiencing issues due to inactivity. “Their muscles function differently, and this must be taken into account during treatment and rehabilitation.”