I pulled this from a nutrition course text I'm studying.
"The pre-exercise meal is ideally high in carbohydrates, low in protein and fat, and eaten about 3 hours prior to exercise. This is important because it takes this long for the stomach to empty and glucose to enter the bloodstream. If too much protein and fat are present in the pre-exercise meal, this will lengthen the time it takes the stomach to empty."
Shoot, I've been eating about 80g low GI carbs with 55g protein(I eat this amount 4 times a day because It easily fits into my schedule) about 1 - 1 1/2 hours before workouts. On top of that I'll have a protein shake about 15 min before exercise and one after. Now I've known about how proteins and fats will slow down digestion from the reading I've done right here. I just never realized it took so long for breakdown. My thinking was I would eat an hour before and have enough glycogen stored to fuel me and feed the muscle until I was through.