conflicting carbohydrates

I'm very tired lately.  Today my lunch nearly knocked me unconcsious, which tanked my mood to boot.  I know that a heavy carb lunch (like rice stir fry) will cause you to crash and get very sleepy.  Carbs are also needed to give you energy when you are working out.  I've been slacking, but I mean to get back into it.  I'm really tired of (heh) getting tired at work.  Gotta love that eternally depleting fleshy prison we're stuck with.

What do you eat for lunch that gives you energy?  What do you eat that knocks you out?