Thanks.
Sebastian Weber?
The underlying rationale sounds reasonable to me. I am agnostic towards Peter Wagner's theory of vo2max (
https://pubmed.ncbi.nlm.nih.gov/36434438/) where peripheral factors (muscle metabolic capacity, including mitochondrial volume and function) can act as aerobic capacity constraints along with more traditional central factors (stroke volume, blood volume and hb mass). But it sure popped into my mind here. More oxygen does not translate directly into performance unless the peripheral side is capable of using it, basically.
So assume Wagner is correct, and you have two neat targets for a regime beside recovery stuff: good ol' blood manipulation to drive central performance limiters further out; and the new mitochondria targeting stuff to really push the peripheral constraints out, too. Now you can theoretically attain a higher vo2max still, in comparison to just working the central side. So higher 5min power, not only higher threshold.
Of course, it is well known that the peripheral side of things is the more important constraint of sub max, threshold type performance, and endurance. And you get that too by pushing mitos up. So push mitos up and you never get tired, basically.
Since Pog's PDBF performance San Millan has been going on ad nauseam about how his lactate meter pinpointed, totally unique type of zone 2 rides are the key to mito development. But besides all the hubbub, this is bread and butter endurance riding, and everyone does it... He also prescribed the same stuff to Garmin riders when working with them, but the results were not, hmm, as revolutionary.
I believe the body is at the same time too dumb and clever and thus insensitive to making such ultra fine grained training intervention protocols game changing. Research is pretty blunt: volume rules the roost in mito development, as it pushes up mito volume. Intensity then targets mito function.
But assume one can teach the body new tricks, then we are talking.
And if it turns out something like you posted about is indeed taking place, then of course the hallowed ultra special Z2 talk would be just what it is, a smokescreen.