Flip The "Fast-Fat-Burning" Switch | Neuroscientist Andrew Huberman

so again this isn't really an issue of how long you exercise it's intensely you exercise and therefore what fuel source you're drawing from so hopefully I've made that clear but basically you need to deplete glycogen or through high intensity exercise and then move to a steady state exercise that will allow you to burn more fat or you need to perform a medium intensity or low intensity type exercise for a long period of time before you shift over to burning fat and indeed it seems that going into all that fasted will facilitate the burning of more fat overall but if you can't even get to the exercise if you're somebody who just can't do the training at all you're unwilling to or you're incapable of training unless you eat something then obviously eating something makes the most sense