I have a question regarding the relationship between glycogen-optimization and fat-burning optimization over 18+ week training plan. From my understanding, how you fuel your training over an 18-week plan will determine your best metabolic pathways during an event. Also, I understand that training each of these pathways are two sides to the same coin, meaning you can only accomplish one at a time. First of all, is my understanding correct? If so, then how would you balance the optimization of these two pathways over a 18-week plan for a gran fondo event (9K+ climbing)? My guess would be to work on fat-burning optimization during base-training, then shift to glycogen 6-8 weeks before the event.
The goal is to have a strong aerobic engine (rely less on glycogen) for 80% of the terrain while also being able to process simply sugars during the VO2 efforts during the big climbs. I understand, specificity in training 6-8 weeks before the event is key, so this is the base of my above assumption.