When it comes to getting ready for race day or an event you need to be topping up Glycogen and hydration levels so as not to end up hitting the wall or getting cramps.
I tend to drink fluids throughout the day aiming for 2-3 litres of water (herbal/green teas included) if you are a coffee drinker then no more than 2 cups. You are aiming to have your pee a straw colour or clear.
My preference is to eat carbohydrates that are low GI so sweet potatoes are good and porridge or brown rice. Try to avoid fatty foods and alcohol (which acts as a diuretic). If you can tolerate it then look at eating wholemeal pasta with the addition of fish or beans, brown rice with chicken or tofu or Jacket potato with tuna or cottage cheese. Essential mix of protein and carbohydrates.
The day before a race my eating pan might be a little like this; porridge and berries made with rice and almond milk followed by scrambled eggs, mushrooms and spinach. My snacks will be rice cakes and peanut butter or oatcakes and hummus or nut butter. A baked sweet potato for lunch with some form of protein and plenty of salad or greens. Mid afternoon snack a protein shake or homemade energy/protein bar. Dinner might be risotto. You could eat pasta with a tomato based sauces or rice dishes (not a greasy fried rice, Indian or Chinese dish).
Come race day the focus again is on topping up the glycogen level, maintaining blood sugar and staying hydrated.
Through trial and error I prefer to have my main pre-race meal 2-4 hours before, keeping it simple with porridge and fruit made with low fat, rice or almond milk. Toast/bread with honey or jam or low fat yoghurt and fruit. For those of you that tend to get a little too nervous and feel that solid food is not going float your boat then maybe try having a meal replacement drink. Do not under any circumstances turn up with an empty stomach or you will not finish.
Two hours before try and drink 500ml fluid, not an energy drink (by which I mean the sort that give you wings etc.) but you could have a sports drink or make your own version. 15-30 minutes before take on board between 125 and 250ml of liquid. If you intend to have a coffee drink at least 30-60 minutes before hand.
One hour before the event have a smoothie, yoghurt drink, fruit, an energy bar, dried apricots or rice pudding.
At the end of the race be sure to take on board a recovery food/drink, can be a sports drink or protein shake. You could have flapjacks, granola or energy bars (try and make your own), fresh fruit, a sandwich roll or bagel with meat, fish, egg or cheese, or dried fruits and nuts.
To summarise for race day;
Low GI carbs, low fat, low protein, low to moderate fibre, not too bulky or filling, not salty or spicy, easy to digest. Keep it wholesome and real.
Fuel up well and you will have a good race. Neglect this and you will be cold and miserable and want to give up before you have even started.