I think there is something big being left out here…..electrolytes. Water is great, but if too much water is consumed, especially during a long run your system will actually flush out sodium (electrolyte) and that is bad.
I don’t know all there is to know by far (my training partner is researching now and is a biologist), but I’m getting there. I know it’s very difficult to get what we need in potassium. As sweaty summer runners we need somewhere between 4000-6000 miligrams of potassium. A banana has about 450mg, cup or yogurt 350mg, tomato, 550mg. As you can see it takes alot of eating to get what you need. Sports drinks contain some. Gatorade has a little, Gatorade Endurance has 3 times more than Gatorade. I believe it has twice as much sodium also.
If you feel parched during or after a run think about electrolyte balance. Don’t drink pure water. If I drank all water before, during, and after runs I wouldn’t just be lacking electrolytes, I’d be struggling even more to get the caloric intake I need for the day.
I’ll have to reflect more on sodium and chloride another time. Still as runners we need about 2-3 times the RDA of these electrolytes also.