I had a trainer who always recommended that I workout 3 hours fasted. He never wanted me to have a shake or something before the workout. His reasoning was this - you can have a workout based on calories, or a workout based on hormones.
In a caloric workout, you're using whatever is in your glycogen stores. That's probably where those pre-workout shakes come into play. Your body will use that as energy to get you through the workout
In a hormonal workout, you're pretty much using adrenaline to get you through. You're forcing your body to find the energy. It's tougher to get a workout started that way, but a hormonal workout will be more intense.
He would use the caveman example to justify this. If a hunter hasn't eaten for a couple of days, that doesn't mean that he says he can't hunt because there's nothing in his system. If anything, he will work harder to make the kill. Survival response. I've never heard of the Warrior Diet before, but it seems to follow the same concept (you would probably have the most food after you had worked out/made the kill).
There might be some truth in this. All I know is that ever since I tried working out on an empty stomach, I've never gone back to having pre-workout shakes. I definitely don't feel weak while I'm working out.
Last edited by SwollPuppy; 05-06-2010 at 06:33 PM.