Low intensity cardio(walking) on an empty stomach?
I've read in several places that this is a great way to lose fat, with one source going as far as to claim that you burn 300% more fat in the morning before you eat anything if you take a brisk walk before eating. While this seems like a pleasant notion, my current understanding of fat loss doesn't seem to add up with the claim.
The claim seems to be that if you don't have any "fuel" in the morning and you were to do cardio, your body would burn more fat than usual. As I understand it, your body is never burning only fat, and it seems like walking on an empty stomach would burn exactly the same amount of fat, but incidentally burn off much more muscle as well since you are running on zero carbohydrates.
I'm not the most knowledgeable on these things, but am I missing a piece of this equation, or is this all just claptrap?