Before you begin your training you should fill up your nutrition reserves. The best nutrition before training and competition is to get complex carbohydrates approx. 3 hours before training/competition.
Training and Competition
During training and competition you should especially provide yourself with carbohydrates. On longer training stints (3 hours and above), it is important that you also get something to eat in order not to lose power on the way.
After training and competition, the body kind of lets a window remain open for approx. 4 hours. For these 4 hours the body is especially susceptible to consuming nutrients through the diet you eat and drink.