Kirito is light years ahead of INODA both physically although the anime doesn't mention it, he was pure fiber and had kendo training every day with Suguha. So his stamina is through the roof while the other would be a lazy and ugly fat man with a terrible diet, supposedly with a big penis but zero stamina, he would die doing it xd
Inoda
has stamina what're you talking about? Yea he may not be muscular, but in this recent update, it's shown that he had nonstop sex with Kyoko for over 30 minutes in Asuna's room. Unless you're doing it slowly and gently, sex is a workout (especially with how intense Inoda goes in some of these scenes). Most people can't even do it for 30 minutes, let alone as intensely as Inoda was doing it.
And Kirito quit Kendo at like the age of 10 or something, he's like 18 now, so that "stamina" he built up doing Kendo is basically nonexistent. We're told Kirito looks fit when Inoda sees him in only his underwear, so he must be doing the bear minimum of fitness to keep in shape (even tho we haven't seen him do anything physical outside of FOG), but don't count Inoda out when it comes to stamina. I think some of y'all forget that sex isn't as easy to do as like a 15 minute walk.