Some points to be noted: hydration is important. Apart from water, include fruits which will ensure minerals and vitamins along with high glycemic value fructose. Tender coconut is a best natural sports drink. Protein rich diet is also needed to build and maintain muscles : include legumes, soya, whey and eggs. Non-vegs can include fish and meat. Don't totally avoid carbohydrates as you need readily available energy for endurance : Include fibre rich cereals.