3. Avoid Sugars
Avoid simple sugars in your fuels; use complex carbohydrates only.
For workouts or races in the 2- to 3-hour or longer range, 10-15% of the calorie content in your fuel should come in the form of protein, ideally soy protein. This protein donation helps satisfy energy requirements more completely while also helping prevent muscle tissue catabolism.
FACT: Simple sugars (glucose, sucrose, fructose, etc.) are inefficient fuels for exercise, and they're health hazards when consumed regularly in typical dietary quantities. These "ose" sugars give you energy peaks and crashes, and they also have a severe limitation on absorption. They need to be mixed in weak concentrations for efficient digestion, which means you can only intake about 100 cal/hr. You can consume more, but you can't absorb more. You'll only get sick trying. Complex carbohydrates, however, absorb at about three times the rate as simple sugars. Plus you get smooth, steady, reliable energy - no peaks and valleys.