The continued fatigue for no apparent reason that many of those affected by persistent COVID experience has a biological cause that has just been identified by a team of scientists from the UMC Amsterdam and the Vrije Universiteit Amsterdam (VU). Specifically, what they have discovered is that the mitochondria in the muscle cells of these people produce less energy than those of healthy individuals.
“We saw several abnormalities in the patients’ muscle tissue. At the cellular level, we saw that the muscle mitochondria, also known as the energy factories of the cell, function less well and produce less energy,” explained Rob Wást, assistant professor in the Department of Human Movement Sciences at VU. “So the cause of fatigue is really biological. The brain needs energy to think. Muscles need energy to move. “This discovery means that we can now start investigating an appropriate treatment for those with long-term COVID,” adds Michale van Vugt, Professor of Internal Medicine at UMC Amsterdam.
Although most people who become infected with the SARS-CoV-2 coronavirus recover in just a few weeks, it is estimated that around one in 10 infected people will suffer from what is known as persistent or long COVID, the symptoms of which include cognitive impairments. (brain fog, loss of memory or attention), fatigue, exercise intolerance, breathing difficulties, postural orthostatic tachycardia syndrome (POTS), gastrointestinal problems, etc.
Light physical exercise for patients with long COVID
The new study involved 25 long-COVID patients and 21 healthy individuals who acted as a control group. They were asked to pedal a bicycle for 15 minutes, and the test caused a long-term worsening of symptoms in people with long COVID, known as post-exertional malaise (debilitating fatigue that intensifies with physical, cognitive or emotional activity). . The researchers analyzed blood and muscle tissue a week before the cycling test and one day after it.
One of the theories about long COVID is that coronavirus particles can remain in the body of people who have had SARS-CoV-2 infection, but, Van Vugt noted, they saw “no indication of this in the muscles right now.” Additionally, the researchers found that the heart and lungs were functioning well in the patients, meaning that the lasting effect of COVID on the patient’s abilities is not due to abnormalities in the heart or lungs. The results have been published in Nature Communications.
“Because symptoms can worsen after physical exertion, some classic forms of rehabilitation and physical therapy are counterproductive to the recovery of patients with long COVID”
These scientists have warned that exercise is not always good for long COVID patients. “In concrete terms, we advise these patients to be aware of their physical limits and not to exceed them. Consider a light effort that will not lead to worsening of the discomfort. Walking or pedaling an electric bike is good for maintaining physical fitness, but keep in mind that each patient has a different limit,” explained Brent Appelman, a researcher at the UMC in Amsterdam. “Because symptoms can worsen after physical exertion, some classic forms of rehabilitation and physiotherapy are counterproductive to the recovery of these patients,” concludes Van Vugt.
