Having gone back and forth on this (a 16-hour fast for a several week period more than one time), and having read a bunch on the topic, I've concluded thus far that, fundamentally, there's no one-size-fits-all for human bodies. In other words, human bodies are so complex that results for almost any food program vary a lot.
Aside from the individual factors, which include your gender and age and whatever uniqueness about your body that we don't know yet (like effects of gut flora on metabolism), there's the type of exercise you do.
If you do long distance running or cycling, at one extreme, it's obviously a no-go. If you do a short conditioning workout or strength workout right before breaking your fast (if you're lucky enough to have a schedule that allows that), that sounds okay.
There's some speculation that fasting 'resets' the gut flora, or that there's a benefit to 'giving the digestive system a rest', then there's some science around the impact on fasting on circadian rhythm reset benefits, some other science around fasting to 'reset the immune system.'
My personal experience was that I didn't get much benefit in terms of body fat cutting, I didn't notice a performance increase or decrease in the gym (where I do strength training and calisthenics primarily with a bit of cardio). I DID notice I was obsessing over food in the mornings and when 2pm came around, there was a feeling of accomplishment.
I'm not sure it was worth it for me. As for everyone else, the jury's still out. It's just that I'm not convinced it'll be back within my lifetime in this complex area of study.
Aside from the individual factors, which include your gender and age and whatever uniqueness about your body that we don't know yet (like effects of gut flora on metabolism), there's the type of exercise you do.
If you do long distance running or cycling, at one extreme, it's obviously a no-go. If you do a short conditioning workout or strength workout right before breaking your fast (if you're lucky enough to have a schedule that allows that), that sounds okay.
There's some speculation that fasting 'resets' the gut flora, or that there's a benefit to 'giving the digestive system a rest', then there's some science around the impact on fasting on circadian rhythm reset benefits, some other science around fasting to 'reset the immune system.'
My personal experience was that I didn't get much benefit in terms of body fat cutting, I didn't notice a performance increase or decrease in the gym (where I do strength training and calisthenics primarily with a bit of cardio). I DID notice I was obsessing over food in the mornings and when 2pm came around, there was a feeling of accomplishment.
I'm not sure it was worth it for me. As for everyone else, the jury's still out. It's just that I'm not convinced it'll be back within my lifetime in this complex area of study.