My problem with IF is that I need energy in the morning because of bicycle commute, and I also want to have a warm meal in the evening after I come back from work. This could only work if the feeding window was 10-11 hours wide.
Try biking harder/longer so that you use up all your blood sugar and convert your metabolism from glycogen to ketones.
Going on an hour or longer run is part of my secret to extended fasting. Exercise-based switching of your metabolism makes the first and second day of fasting NOT suck so bad.
So that's literally the opposite of your assumption, that the exercise makes you "need energy." If your like 99% of people, you already have plenty "energy" throughout your body.
What are you actually experiencing?
Blood sugar withdrawal. Your "need" for energy is actually a craving for the high glycemic ingredients in your food that cause physical addiction like symptoms, like feeling "hungry." And you may find it surprising that "hunger" isn't one of the things people experience on an extended fast when properly hydrated.
Your "need" is easing the pain of withdrawal. Not anything to do with "energy."
Edit: my SO informed me that there are some situations where woman benefit from certain foods after exercise for hormone regulation. But she also concurs that the evidence is pretty clear that men were built for intermittent fasting.
Maybe you're simplifying for the sake of brevity, but this notion of "use up all your blood sugar" and "switching" (as if binary) between glucose and ketones is pervasive and frustrating. That is not how things work.
Unless you have some metabolic disorder, after your hour+ run your blood glucose is still going to be within, maybe on the low end of, the normal range. Even if you've completely depleted your liver of glycogen, which is unlikely for anything short of marathon distance unless you were already low. If your blood sugar was low (never mind gone) you'd be in serious trouble, dead before long if not rectified.
It could be mostly an habit/mental thing. I go to the gym fasted (anywhere from 10 to 20hr fast) and I ohp/squat/deadlift moderately heavy weight for 60-90min. I also commute by bike fasted
Your body doesn't run out of energy that fast, we've just became very used to over feeding
The data on Time Restricting Eating shows that you most probably will experience benefits even with a feeding window as wide as 12 hrs. I do 10hrs and it's been very good for me.
I think people greatly over estimate how many calories you burn while working out. It's very little, unless you're able to train the entire day I doubt the average person is burning many calories from moderate exercise.
Not trying to say exercising isn't worth while, it is but using it as the sole means of weight loss isn't fruitful gotta change the diet as well.
If you only do cardio, ie bike and run, then you are actually WORSE OFF.
Calories burned is directly proportional to muscle mass!
Air squats. Pushups. Crunches. Ten of each of those a day. It can be done in 60 seconds. 10X that and you'll be shredded without running or cycling a day in your life.
Yes to strength training first. However, please be careful doing only highly repetitive exercises like pushups and crunches every day - it's a good way to develop joint injuries as you get older. Build up slowly and switch it up - like a healthy diet, variation is the key to longevity!
From personal experience, reducing calories intake is the only thing that works. Exercising only burns a noticeable amount of calories to if you are a really good or elite athlete who does a lot of hours everyday at a very high intensity.
Anyway, exercising is always necesary to keeping muscular mass.
Pre-covid I was cycling a minimum of 25km/day.
For 8+ years.
I've always been a fat bastard.
IF including 2-week (water-only)fasts during a 3-year period had no noticeable benefits besides 10-20 pound drops at the start. (Keto-only on & off provides brief weight loss.)
My point, "decent" exercise doesn't guarantee weight loss.
