I feel insane seeing stuff like this because this research already exists for Myalgic Encephalomyelitis, a post viral condition caused by multiple types of viral infections that a LOT of people with "Long Covid" meet the diagnostic criteria for.
This article mentions that ME/CFS is a "similar complex condition" but that's DEEPLY underreporting the similarities. The phrase "post exertional malaise" (now researchers are trying to replace it but this article uses that phrase) was INVENTED for ME/CFS. It's the only known condition, before "long covid", that causes these kinds of symptoms after exertion!
It's good to know for sure that it's the same mechanisms at play when the inciting viral infection is Covid and not, for instance, Epstein-Barr or RSV, but half the time it doesn't seem like researchers are making comparisons at all, just reinventing the wheel and acting like "long covid" is a totally new phenomenon with no previous point of comparison.
There are literally drugs in human trials to try to treat the mitochondrial dysfunction in ME, this dysfunction is well-established and fairly well understood and I feel insane when ppl report on long covid without mentioning that there is already a named and studied condition that accounts for this subset of symptoms!!
SOME researchers are drawing comparisons but they're largely ME researchers who everyone else is largely cignoring because of the widespread perception that ME is a fake disease for lazy women.
That same perception btw is why "graded exercise therapy" (GET), or exercise gradually increasing in intensity, cwas for years the go-to treatment despite MOUNTAINS of evidence that it makes ME patients sicker. Some end up permanently bedbound and unable to even eat or drink without a feeding tube/IV because the damage is so bad!
The GET recommendation was finally changed only in the past few years in the US and the UK, and many doctors hate that they're not allowed to recommend it anymore, because they insist despite the evidence that ME/CFS is psychological and ME patients are just "deconditioned" and too lazy to do anything about it.
Now the same kind of "treatment" is being recommended for long covid patients despite evidence showing exercise is having the same kinds of cellular effects as it does in ME patients. "Taking PEM into account" sounds gentler but I'm deeply concerned about the reinvention of GET for patients who meet all the criteria for an illness that's been shown definitively to become permanently worse with GET.
This mitochondrial damage is progressive in ME, and there's no reason to believe patients who meet all the criteria of ME after Covid won't experience the same progression if they force themselves past their energy envelope in such a systematic way.
PEM happens in part (it's complex) because your anaerobic threshold gets dramatically reduced with this mitochondrial damage. Every time you hit that anaerobic threshold, you're injuring your cells more and more. It's deeply worrying that GET is being recommended for long covid patients who meet the criteria for ME when research like this study keeps showing it's the same phenomenon.