How do people that do this exercise? are they mostly sedentary?
I mostly ride bikes for exercise and need fuel at least every hour on a ride or else I will bonk out. My output is 500kcal/hour based on power meter, a 4 hour ride would be 2000kcal, it's not doable without some food intake.
Your body adjusts to using fat as fuel. I’m no scientist/doctor but I’m training for a marathon and I find I perform much better than when using gels or bars or any of that other processed ‘fuel’ I used to use.
I also love weightlifting while being fasted. One meal end of day for me has put me in the best shape I ever have in 36 years. So much that I actually took up running haha.
I also ride bike, and used to bonk, but it didn't take long for my body to adapt to using fat as fuel. Half the battle was mental: accepting that I truly didn't need to eat anything; my body already had all the fuel it needed.
Then I could wake up, ride hard for hours (hilly terrain), and feel no need to eat until the afternoon.
Agreed that it's mostly mental. Missing a meal isn't starvation, and the body/mind adapt.
I do IF and do most of my physical activity before my first meal every day. It was hard at first, but now it's when I have the most energy and clarity.
There are two kinds of IF: a skipping a meal kind, when you only eat during a 6-8 hour window and it's easy to fit a 4 hour bike ride in there or a skipping a day kind, when you don't eat every third/fourth day, then you can use the fasting day to do a recovery ride or even rest.
I mostly ride bikes for exercise and need fuel at least every hour on a ride or else I will bonk out. My output is 500kcal/hour based on power meter, a 4 hour ride would be 2000kcal, it's not doable without some food intake.