Practically speaking, it is not possible to make an accurate recommendation on how much to feed an individual exercising dog. Theoretically speaking, we could do the maths and estimate the daily energy requirements in kcal/day based on what we know from the different studies that were performed on canine athletes and then, knowing the energy density of the diet, determine the amount of food a dog should be fed on a daily basis. However, this will just be an uncertain estimate of the true requirements of any individual animal.
It is best therefore not to rely on a calculation to determine how much to feed an exercising dog but instead to adjust the amount fed to ensure that he maintains an ideal body condition (see chart above).
Exercising dogs better be lean : some studies suggest that dogs live longer and perform better when they are fed less food and exercising at a consequently slighly weight less than they would if they were given free access to food.
DR. EMMANUEL FONTAINE 