The timing of nutritional intake is very important not only for improved sports performance, but also for general health. The most effective time and manner in which you take the nutrients you need varies depending on numerous factors including the type of sports, your purpose, amount of practice, season, body weight, gender, age, and general health condition.
The method of dividing an annual training program into several shorter periods and training systematically for specific goals in each period is called "periodization." The important thing is to set nutritional management goals for yourself (or the athlete if you are a coach) for each period based on a fundamental understanding of sports nutrition. Having done that, decide what, how much, when, and how to eat, and stick to the plan.
One interesting point with sports nutrition is that it does not have to be done exactly by the book; but rather can be tailored to suit individual needs.