JJ Virgin tested fasted versus fed workouts and found that intense exercise needs glucose and glycogen to perform well. Fat loss comes down to overall daily energy, not when you eat. Eating 1-2 hours before and after workouts gives your muscles the carbs and protein they need.
I did a couple months where I was really testing out fasted versus non-fasted workouts because there was so much buzz about fasted workouts. And I kept thinking, I don't know that this makes so much sense because really when you're doing intense workouts, you're really going to use more glucose and glycogen than you are fat anyway. So the whole point of fasted workouts was you'd burn more fat, but I'm like, I'm doing intense workouts. I'm not really looking at burning fat. And if you really want to burn fat, it really comes down to overall energy flux throughout the day. And you really want to think about eating around your workouts, like an hour or two before and then after, so that you're supplying your body what it needs in terms of carbs and protein to refuel your glycogen stores, the energy stores of carbs in your muscles, so you can use those to work out harder, and that you've got the protein that you need to fuel muscle protein synthesis and refuel those amino acid stores.
