I stumbled upon an interesting article on Long Covid, and we can see similitude with POIS. The article mentions similarities with Lyme, chronic fatigue syndrome, etc... if the authors knew about POIS, they may have included it in their list:
"
How Long COVID Defies Simple SolutionsLong COVID is a “dynamic disability” that requires health professionals to go off script when a patient’s symptoms don’t respond in a predictable way to treatment, says David Putrino, PhD, a neuroscientist, physical therapist, and director of rehabilitation innovation for the Mount Sinai Health System in New York City. “We’re not so good at dealing with somebody who, for all intents and purposes, can appear healthy and non-disabled on one day and be completely debilitated the next day,” he says.
Putrino says more than half of
his clinic’s long COVID patients told his team they had at least one of these
persistent problems:
- Fatigue (82%)
- Brain fog (67%)
- Headache (60%)
- Sleep problems (59%)
- Dizziness (54%)
And 86% said exercise worsened their symptoms.
The symptoms are similar to what doctors see with illnesses such as
lupus, Lyme disease, and
chronic fatigue syndrome – something
many experts compare long COVID to. Researchers and medical professionals still don’t know exactly how COVID-19 causes those symptoms. But there are some theories.
Potential Causes Of Long COVID SymptomsPutrino says it is possible the virus enters a patient’s cells and hijacks the mitochondria – a part of the cell that provides energy. It can linger there for weeks or months – something known as viral persistence. “All of a sudden, the body’s getting less energy for itself, even though it’s producing the same amount, or even a little more,” he says. And there is a consequence to this extra stress on the cells. “Creating energy isn’t free. You’re producing more waste products, which puts your body in a state of oxidative stress,” Putrino says. Oxidative stress damages cells as molecules interact with oxygen in harmful ways.
“The other big mechanism is autonomic dysfunction,” Putrino says. It’s marked by breathing problems,
heart palpitations, and other glitches in areas most healthy people never have to think about. About 70% of long COVID patients at Mount Sinai’s clinic have some degree of autonomic dysfunction, he says.
For a person with autonomic dysfunction, something as basic as changing posture can trigger a storm of cytokines, a chemical messenger that tells the immune system where and how to respond to challenges like an injury or infection. “Suddenly, you have this on-off switch,” Putrino says. “You go straight to ‘fight or flight,’” with a surge of adrenaline and a spiking heart rate, “then plunge back to ‘rest or digest.’ You go from fired up to so sleepy, you can’t keep your eyes open.”
A patient with viral persistence and one with autonomic dysfunction may have the same negative reaction to exercise, even though the triggers are completely different."
Source:
https://www.webmd.com/covid/news/20220803/why-exercise-doesnt-help-people-with-long-covid ( probably not accessible to the public, I need to log in to have access)
What I also found interesting is their presentation of two different causes of long covid symptoms: problems with energy production in mitochondria, or autonomic dysfunction causing cytokines imbalance.
Just after that, it is said that both types have the same negative effects from exercise, but with totally different triggers. This is much in line with my hypothesis of different types of POIS leading to the same symptoms.