The limitation in carbohydrate fueling during intense exercise is the gastrointestinal tract's tolerance, not the mitochondria's ability to utilize the substrate.

“exactly yeah and I'm going to be a little bit now I'm going to be very crude there but we can think of to put it this way what brings us to V2 Max is not because we're thinking that we want to have a high V2 Max oh no I want to you can you can start you can start to breed increase of ventilation now as high as you want but you won't increase you will for you yes you will increase your oxygen but you'll never get to your maximum level without sufficient work you need work exactly not even close to it you will bring it up but you will not be just because you're breathing more and you you're working more when you're doing that”