I tend to do a little bit of both; everything in good measure. In my opinion, the combination of IF and something akin to Keto approach to food composition(low carb, high fat, low-medium protein) is only improving my recovery and performance. If the idea is that our body actually uses fat as it should, as an active source of energy instead of a battery that keeps sitting around, things should work at the very least equally as well if not better. This is a very personal experience, of course.

I do CrossFit and IF.

CrossFit on fast days is easy.

Doing it the day after a fast day is hard.

I write more about it at http://go.DanielOdio.com/health