[ordu]

Hmm... Maybe the dynamics is different? When you push yourself physically your body don't stop getting oxygen suddenly, just the rate of oxygen absorption is less then you are consuming, and it is getting worse, when excesses of lactic acid reach your liver and it starts to suck out oxygen from blood to metabolize it. But the heart pumps blood at its maximum, some limited amount of oxygen is available.

I'm not sure how VF works, but maybe the deficit of oxygen develops much faster, so it leads to complete blackout in seconds?

> there are 4-5 seconds of normal consciousness when I can try to make sure I fail safe. Like sitting down.

Fainting and workout take more time. Definitely more. When I fainted it took tens few minutes from the moment I broke my leg. When I ride my bike up to a hill with all my might, it takes a couple of minutes to see darkness in my eyes.