Best foods for hydration and endurance are fruits and vegetables. Under normal circumstances, you can actually get most of your fluid from food if most of your diet is composed of fruits and vegetables. I recall a study in which endurance was tested on bikes; and, vegetarians had superior endurance to those who ate a lot of meats. I tested this in my own life and confirmed it. Something to consider, for sure. Profuse sweating obviously creates the need for more water.