I have been working with the P90X videos over the last couple of weeks with great results. However, I am ABSOLUTELY exhausted afterwards and almost useless for like two hours! I have great energy and enthusiasm to get through the workouts but as soon as i sit down im done.

I cannot eat any wheat products before working out and I dont really want to waste a grain or something like that on a pre-workout meal...normally I have a serving with my evening meal or certified organic wheat free oats. I tried an apple with peanut butter but it didnt do very much nor does my green monster, surprisingly.

I eat either a fat free Greek yogurt or a banana.

I usually have a piece of cheese and a small apple, or a serving of almonds.

Yeah, I agree with the banana comment. Or sometimes I make my own latte- use milk and water and add some coffee. Seems to give me extra energy
Also, since you are doing p90x, you may want to increase the servings of carb? Add one a day? Or some fruit? You are doing an intense exercise that tends to be for bulking a bit so your body may be asking for extra glucose as glycogen stores are being depleted.

I was going to say something like a smoothie...mine is plain yogurt, blueberry, banana, +/- handful greens, and stevia. I sometimes make a batch that lasts 2-3 days. Not real pretty til ya stir it, but saves a lot of time.

I agree with maybe picking up another carb as it seems like you are only getting one per day now.

A banana seems to be my go-to pre-workout food. Oh, and a B complex vitamin if I'm feeling a little draggy. It keeps my energy up through the workout.