Restrict caloric intake to 120-150 cal/hr during exercise.
FACT: Your body can't process caloric intake in an amount that comes anything close to your expenditure rate. If you want to achieve your best performance, DO NOT follow the "calories out, calories in" protocol that some "experts" recommend. Instead, replenish calories in "body cooperative" amounts, allowing your fat stores to make up the difference, which they will easily do. For most athletes, 120-150 calories/hour will be 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 more than 150 calories per hour. However, it's always better to err on the side of too few, as more can easily be added.