In general you don't want to just load up right before a workout. You want a steady consistent intake of carbohydrates, protein and water. That way you get consistent blood sugar levels instead of peaks and valleys. You don't want to just carboload before the workout because then you'll get a blood sugar spike and then a drop.
But, if the workout is under a hour I don't worry about it, but if it's over an hour I like to have a big bowl of pasta a couple hours before. After a workout you want calorie replacement that's 75% carbohydrates and 25% protein.