Long COVID Fatigue Linked to Malfunctioning Mitochondria

At least 65 million people around the world have long COVID, a condition where they continue to experience COVID-19 symptoms for months after their symptoms originally start.

The most common symptoms of long COVID are fatigue, dizziness, mobility issues, sleep problems, cognitive impairment, and brain fog or inability to concentrate.

These types of lingering symptoms can have a profound impact on a person’s life. A study published in June 2023 found more than half of people with long COVID reported their work, home, social, and private lives were severely impacted by the symptoms, with fatigue being the main problem. Scientists are still unsure as to why some people develop long COVID and its symptoms while others do not.

Now researchers from the Amsterdam University Medical Center are helping to provide some answers with their new study — recently published in the journal Nature Communications — that found the fatigue experienced by those with long COVID has a physical cause.

For this study, Prof. van Vugt and her team recruited 25 people with long COVID and 21 healthy control participants. They were all asked to take a cycling test for approximately 15 minutes, that was designed to push them to maximum exertion.

According to researchers, the cycling test caused a worsening of symptoms in the participants with long COVID, known as post-exertional malaise (PEM), resulting in worsening of fatigue for up to 7 days after.

Scientists examined blood and muscle tissue samples from all participants both one week before the cycling test and one day after.

They found various abnormalities in the muscle tissue of the participants with long COVID, including lowered functioning of the mitochondria of the muscle. 

Known as the “powerhouse of the cell,” mitochondria are responsible for making the energy needed to power the body’s cells.

When asked about the next steps planned for this research, Prof. van Vugt said they plan to examine whether the same muscle alterations can be found in other post-infectious patients to hopefully uncover the cause of these changes in the muscle, leading to proof of concept studies for treatment.


Appelman, B., Charlton, B.T., Goulding, R.P. et al. Muscle abnormalities worsen after post-exertional malaise in long COVID. Nat Commun 15, 17 (2024). https://doi.org/10.1038/s41467-023-44432-3

Long COVID fatigue linked to malfunctioning mitochondria. By Corrie Pelc on January 13, 2024 . MedicalNewsToday. Retrieved January 17,2024 from: https://www.medicalnewstoday.com/articles/long-covid-fatigue-linked-to-malfunctioning-mitochondria 

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