it's the shoes. like when swimmers started using those sharkfin bodysuits in the early 2000s and every swimming WR went down in short order.
yea man it's a bummer.
it's beyond a ban now, unfortunately. we're just looking at two different sets of records now. but it's all going to get blurred. really sucks.
hope they ban them from olympic marathon etc.. but it's also a tough questions because shoe tech varies so much, even without the double/triple carbon fiber spring action systems. bleh.
i tell you what tho.. get a pair of vaporfly 4%'s or any of these shoes.. and you'll def respect the performances a bit more - i don't know how they run in these new shoes. they feel like clown shoes. ran a few times in them and absolutely hated it. i'll take my minimalist af 3-4 oz shoes any day over those contraptions.
no idea how they run so fast in them.
pc
Ohhhh don't say that to the shoe maniac, want me to spend 250 euros for shoes i dont really need?
https://www.theguardian.com/sport/2020/dec/06/kibiwott-kandie-breaks-58-minutes-for-half-marathon-wearing-new-shoe-technology
And they are adidas too, although they don't have my beloved boost. It seems that the foam is not so important in the top series, the carbon plates(Nike)/rods(Adidas) do all the job.
Adizeros:

Vaporflys:

they've been hyping up the new adidas for a while now (first saw them on rhonex w/ smiley faces covering them - top secret area 51 technology) .. looks like they are legit lol. tons of adidas athletes now beating the nike athletes lately.