The new review article on muscle adaptations and post-exertional malaise in people with Long COVID was published today in the journal “Trends in Endocrinology and Metabolism”. The researchers from the Vrije Universiteit Amsterdam and the Amsterdam UMC have published new insights into the consequences of changes that occur in the muscles of patients with post-COVID. Their recent review article, conducted by a multidisciplinary team led by muscle physiologist Rob Wüst, sheds light on the potential causes of exercise limitations and post-exertional malaise (PEM) – a core symptom of post-COVID.
Exertion complaints and muscle adaptations
In post-COVID, patients often experience long-term symptoms such as fatigue, muscle pain, brain fog and PEM, where even minor physical or mental exertion can lead to worsening of symptoms. These symptoms have a major impact on daily functioning and recovery.
Through literature review, the researchers identified multiple changes in the muscles of post-COVID patients that may contribute to the decline in exercise capacity. These adaptations provide important insights into the underlying mechanisms of post-COVID and the challenges patients face.
Important findings
- Post-COVID is associated with a shift in metabolism and muscle properties that may explain why fatigue sets in more quickly.
- The mitochondria, the cell's 'energy factories', function less efficiently, meaning that muscles can generate less energy and become exhausted more quickly.
- Problems in the oxygen supply to muscles, possibly caused by changes in the capillary network (small blood vessels that bring oxygen to the muscles) and the endothelial cells (cells lining the blood vessels), can increase symptoms.
- Post-exertional malaise is likely exacerbated by damage to muscle tissue and accumulation of immune cells in muscles after exercise, which can lead to muscle pain.
“While much of the research on post-COVID focuses on the immune system, our work highlights the role of muscle adaptations in the long-term symptoms,” said muscle physiologist Wüst. “This could be an important step in developing targeted treatments.”
Future perspective
The authors emphasize that the mechanisms behind PEM and Long COVID are not yet fully understood, and that there are currently no effective treatments available to directly address these muscle-related problems. However, their findings provide important starting points for further research.
“Our goal is to support both patients and healthcare providers by providing insight into the causes of this complex condition,” Dr. Wüst added. “We hope that our findings will contribute to more targeted treatments and improved patient care.”
For patients and healthcare providers
The researchers advise patients to consult with their healthcare provider to keep physical activities within their limits and to avoid overload. For more information and support, patients can contact Stichting Long COVID Nederland and ME/CVS Stichting Nederland.
The full review article, “Skeletal muscle adaptations and post-exertional malaise in long COVID”, is published in Trends in Endocrinology & Metabolism. See link below.
