Italian endurance coach Renato Canova in his talk at the Podium Education Project last Wednesday in ST Louis presented a great metaphor to illustrate the construction of a training program. He compared constructing a training program to making minestrone soup. The ingredients that are constant are the broth and the pasta; the ingredients that vary are the vegetables. You use different vegetables depending on the time of the year when they are ripe. Very simple, clear and effective, know the key constants in your training that must be there all the time. Introduce different elements and emphasis of training as the body adapts and is ready for them. It is not more complicated than that.