How does exercise increase storage of glycogen and fat?

If the athlete had a fit rich and a poor carbohydrate diet, it would mean that they would have lower muscle glycogen content and a higher rate of fat oxidisation during exercise, when compared with a high carbohydrate low fat diet. The whole effect of such a diet could potentially be a sparing of muscle glycogen, and because muscle glycogen storage is paired up with endurance performance, it is possible that adaptation to a high fat diet could potentially enhance endurance performance. Therefor the athlete could afford to eat fatty things in their diet and be able to use the energy it gives to good use. The athlete would have to perform a lot of endurance exercise so that it does not hinder the performance.