Keeping electrolytes balanced is not as easy as it sounds. Milk, contributes protein.
Tea, fruit juices, coffee, and wine can assist in polyphenol supplementation.
Water is contained in many foods but additional hyrdation is required for optimal balance. Potassium causes fluid retention, but is required by athletes to prevent dehydration. In addition sodium is neccesary to absorb large amounts of fluid.
Mixing carbs and protein is an optimal way to stay hyrated and get maximum nutrients.