Sllightly related response cjrt 7/26/10 8:59:58 AM ET
The best indicator of whether you are ingesting the right number of calories is your weight, adjusting for things like hydration levels since we know a person can lose 4 or 5 pounds in the course of a long run. The body is a wonderful calorie counter. Nutrition in less energy expenditure determines whether one accumulates or not.
Trying to judge things precisely is a mistake. Even the calculators that carefully factor in weight and sex for flat running are only approximations. Running economy differs from person to person.
Eat healthy foods until you are moderately full. If your weight moves other than in a direction you want it to go, adjust slightly. Don't worry about balancing intake and output on a day by day basis. It is much easier to develop a healthy eating pattern and rely upon the body's reserves to deal with unusually high demands.