2. CALORIC INTAKE
Restrict caloric intake to 120-180 cal/hr during exercise.
For best performance, DO NOT follow the "calories out, calories in" advice given by some "experts." Instead replenish calories in "body cooperative" amounts, allowing your fat stores to make up the difference. For most athletes, 120-180 calories/hour is the ideal range.Fewer calories per hour can be processed while running, so adjust accordingly. In very rare instances, larger athletes and hyper metabolic types may need slightly more calories per hour.
Workouts/races of 2 hours or less: choose a fuel with complex carbohydrates, not simple sugars (glucose, sucrose, fructose, etc.). Simple sugars cause energy peaks and crashes, and must be mixed in weak concentrations for efficient digestion. Complex carbohydrates absorb at about three times the rate as simple sugars. Plus you get steady, reliable energy - no peaks and valleys.
Workouts or races of 2-3-hours, or more: Fuel primarily with complex carbohydrates, not simple sugars. Also, 10-15% of your fuels calorie content should come from protein, ideally soy, to help satisfy energy requirements and prevent muscle tissue catabolism.