I keep wondering if intermittent fasting works in domains other than food.
E.g., by analogy, could we train ourselves to hold our breaths longer and longer, making the times that we breathe more efficient in terms of oxygen delivery and Krebs byproduct waste removal (e.g. CO2)? This seems bad because of the Krebs cycle, but maybe it's secretly good...?
Or what about intermittent thirsting? Going a day without any liquids at all, or maybe not drinking water at all before 5pm, or something like that. I'm not sure if dehydration can cause a mode-switch the way hunger can, and water seems so fundamental to everything else that I could see this just messing things up. But maybe...?
Or how about sleep? Circadian rhythms suggest that a roughly daily sleep cycle is needed, but might it work well to be awake for 48 hours and then sleep for 24 (instead of 16 and 8 respectively three times)? Maybe something with appropriate control of Zeitgebers
would let us make the "circadian" rhythm longer than a day.
My default assumption is that all of these are terrible ideas. But that would have been my assumption about regular fasting ten years ago, and I was very wrong about that!