What do electrolytes and sodium have to do with hydration? Is water alone not enough?

Question

Ever since I started running, all I know is that I need to drink a sh*t ton of electrolytes. But I would like to understand why on a physiological level.

In: 576

Answer 1

If your blood has too much water and not enough other stuff in it, the more concentrated solution in your cells will try to diffuse into your blood.

Concentrated solutions always want to diffuse towards a more dilute solution. Moving it in the other direction is like pushing something uphill, and the bigger the difference, the steeper the hill.