A good everyday diet is not adequate by itself as nutritional preparation for your best performance in a marathon or half marathon. Meeting your daily carbohydrate needs and maintaining a high-quality diet will push back the wall significantly by making you leaner and lighter and by enabling you to train harder and perform better in workouts. But to get the very most out of your training you must also fuel your body appropriately within workouts.
No workout should be so hard that it puts you at risk of hitting the wall of exhaustion that is so often encountered in longer races. You should, however, regularly experience a moderate to moderately high level of fatigue in workouts. The same fueling practices that you will use in races to maximize your performance (a topic that we will discuss thoroughly in Chapter 7) can also be used in your more challenging workouts to help you run stronger and to thereby enhance the benefit you derive from these training sessions. Fueling your body appropriately in workouts also serves as practice for optimal race nutrition. As we’ll see in this chapter, though, there are important differences between workout fueling and race fueling. You’ll get the greatest possible benefit from your workout fueling if you approach it somewhat differently than you do race fueling.