Originally Posted by
burritos
I've been doing intermittent dry fasting for over 2 years. OMAD 3-4 week. I wouldn't consider myself that great of rider. I've seen packs of women with higher BMI pass me. But I can do 3-4 hour bike rides with 3-4k ft climbs in a dry fasted state. I don't think I'm dehydrated cause at the end of the ride I always have long mean piss. So if I can build up to it, I suspect anyone can. When you fast and eat less carbs, it creates a requisite demand that your body burn fat for ATP, ketones, and glucose generation. Ketones and glucose of course is ultimately burned for ATP. But ATP is generated in the cell and is not delivered via the bloodstream, so energy delivery through blood stream is done via ketones, glucose, and lipoproteins(for fat delivery). Also, albumin(protein we see in eggs) can also deliver a little bit of fat.
Like I keep saying, if you ride slow enough, then have at it.
But you can't ride quickly for very long doing that type of stuff. I can do 1 MJ an hour at a tempo pace for multiple hours at a time. Suffice to say, there's a lot of energy being put out day after day. That takes a lot of carbs.