Long Covid causes changes in body that make exercise debilitating: Study
Many people with long Covid feel tired, unwell and in pain for lengthy periods after exercise, and researchers say they now know why.
Experts say they have evidence that biological changes are to blame, such as severe muscle damage, mitochondrial problems and the presence of microclots in the body.
“It’s really confirming that there is something inside the body going wrong with the disease,” said Dr Rob Wüst, an author of the study at Vrije Universiteit (Free University) Amsterdam.
Long Covid is thought to affect about 2 million people in the UK alone, and many experience a worsening of symptoms for weeks after a single bout of exercise.
Published in the journal Nature Communications, the study involved 25 patients with long Covid who reported experiencing malaise after exercising, and 21 people who had had Covid but made a full recovery. None of the participants had been hospitalised with Covid, while all had been fit and healthy before catching the virus and were of working age.
Each participant spent about 10-15 minutes on an exercise bicycle, and blood samples and skeletal muscle biopsies were taken a week before and the day after the task.
While there was considerable variation between patients, on average, people with long Covid had a lower exercise capacity than healthy participants.
When the researchers analysed the biopsies taken before exercise, they found that those with long Covid had a greater proportion of white fibres in their muscles than healthy participants. These fibres have fewer power-producing structures, known as mitochondria, within their cells, and fewer capillaries.
The team also found signs that the mitochondria in people with long Covid did not work as well as those in healthy participants.
Wüst said the findings partly explained why people with long Covid had a lower capacity for exercise.
Source: The Guardian