As mentioned in another post, candy can be just as effective to maintain blood sugar levels and is much cheaper. I carry either caramels, Bit-o-Honey, or best of all, those peanutbutter Halloween candies that come in the black and orange wrappers. They taste terrible to me so I don't eat them but the dogs seem to love them. I give one to each dog about every 45 minutes to an hour early in the season when it is hot and the dogs are not in peak shape. Later, they may get one piece every hour to two hours as the dogs seem to pace themselves better and their conditioning gets better. I'll also pack an extra bologna and cheese sandwich for them to eat at lunch break. Energy seems to be maintained at decent levels.