The following outlines what is in my opinion the optimal way to approach race week in terms of fueling:
1) In general, keep your diet consistent with your typical routine. No major changes until 1 or 2 days out (depending on race distance). The only exception is a large meal at dinner about 5 days out which will serve the purpose of ensuring that the final workouts on race week are approached fully stocked in terms of calories and glycogen. The whole idea is to keep glycogen as stocked as possible on race week without overdoing it with calories.
2) Pre-fuel workouts within an hour before with a bit more carbohydrate than you normally would.
3) Drink a recovery shake after ALL workouts even if you feel you don’t need it.
4) Begin carbohydrate loading 1-2 days out depending on race distance with about 10 grams of carbohydrate per day per pound body weight.
5) The day before race day should always start with a large meal and then taper throughout the day such that the last meal is light and low fiber. The idea is to begin clearing your gut. There is nothing that you will do between breakfast the day before the race and the starting line that will deplete muscle glycogen.
Hopefully these tips for race week will help get you to the starting line as fresh as possible.