Originally Posted by
rubiksoval
I've done intermittent fasting for the last 9 months and lost about 15 lbs, but again, pace 100% dictates what you can do while fasted or taking in less carbs. I can go out fasted and ride 2 hours very easy, but I've also bonked numerous times when going just that little bit too hard.
I've bonked in just 30 minutes time multiple times when really depleted (generally after not refueling enough from a big ride the day before).
Even with intermittent fasting, if I'm planning a bigger ride the next day, I either have to consume additional carbs and calories during the "window" or, in the event of a ride with much more intensity, forgo the fasting and eat a substantial amount before and during the ride.
Why? Because your body needs carbs to go fast.
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.