In people who suffer persistently from Covid, the most common symptoms are usually fatigue, a feeling that has a biological cause and is a reaction to the mitochondria of muscle cells producing less energy.
Dutch researchers published a study in Nature Communications in which 25 consecutive Covid patients and 21 healthy people participated.
The study found “pronounced changes in the muscles” of people with long-term Covid, with mitochondria in muscle cells producing less energy than healthy patients.
Research participants had to pedal for fifteen minutes, a test that worsened long-term persistent COVID symptoms, called post-exertional malaise (PEM).
Extreme fatigue occurs after physical, cognitive, or emotional exertion beyond an unknown personal threshold.
The researchers also looked at blood and muscle tissue one week before and one day after the test.
“We observed several abnormalities in the muscle tissues of the patients. At the cellular level, we observed that muscle mitochondria, also known as the cell’s energy factories, function poorly and produce less energy,” explained Rob Wüst of the Vrije University in Amsterdam and one of the signatories. .
The cause of fatigue is “really biological.” The brain needs energy to think. Muscles require energy to move,” said Michel van Vugt from the University Medical Center (CMU) in Amsterdam.
This discovery means – he assured – that we can now start investigating adequate treatments for patients with persistent Covid.
Although one theory about long-term Covid is that coronavirus particles could remain in the body, researchers have seen no sign of this in muscles “at the moment”.
Additionally, they observed that the heart and lungs function well in the patients, meaning that lasting effects on fitness are not caused by abnormalities in those organs. Patients with this disease must monitor their physical limits and not exceed them, although they can walk or ride an electric bicycle to maintain a certain physical condition, CMU’s Brent Appelman said in a statement. Keeping in mind that each person has a different threshold. ,
Van Vugt said that some classic forms of rehabilitation and physiotherapy are also counterproductive to the recovery of these patients, because symptoms can worsen after physical exertion.
Although most people infected with the SARS-CoV-2 virus recover within weeks, it is estimated that one in eight will have persistent Covid, with symptoms such as brain fog, fatigue, exercise intolerance or tachycardia syndrome. efe