a hvg.hu He writes that physical fatigue and decreased performance are a painful problem for those who have suffered from Covid, which occurs mainly during things that involve greater physical stress, such as training. Dutch researchers have now discovered the reasons for this.
In a publication published in the scientific journal Nature Communications, researchers from Vrije Universiteit Amsterdam write that distinct changes are visible in patients' muscles. According to Michelle van Vogt, the study's lead author, this is exactly why fatigue has a clear biological origin.
They confirmed this with a relatively simple test. 25 people with long-term Covid and 21 healthy people were asked to ride a bike for 15 minutes. This does not pose a challenge for most people, but it poses a serious burden for those who belong to the former group.
The problem is in the muscles
The study revealed that the mitochondria responsible for producing energy in muscles produce much less energy compared to healthy people, as The Guardian has already reported.
The researchers took muscle samples one week before the cycling test. It turns out that the percentage of glycolytic fiber was higher in those suffering from long-term Covid, which means that the muscles need more sugar, not oxygen, to produce energy.
After training, not only did the mitochondria function worse, but the muscles also showed signs of more serious tissue damage, which the body was unable to repair.
The research included people who were actively working, fit and in good health before becoming infected. None of them were sick enough to be hospitalized, and their hearts and lungs were functioning healthily even after training.
Meanwhile, researchers also confirmed that they found no sign that long Covid is caused by virus particles in the body. However, according to Brent Appleman, co-author of the study, there is only one thing that can be advised to patients until then:
Don't put pressure on yourself
And they only work on training as much as it doesn't burden them yet.
