Running

Yeah, because following your thirst doesn't work.

It will lead to either dehydration or overhydration just as easily.
The only good way is being properly scientific and measuring your sweat, and rehydrating at that level.
Which is actually what Noakes says: http://www.ingentaconnect.com/content/adis/smd/2007/00000037/F0020004/art00050
"This article argues that humans are designed to drink just enough to maintain plasma osmolality, not necessarily bodyweight, both at rest and during exercise."
Otherwise you might as well just guess.

I don't think Noakes is arguing that our early human ancestors were 'properly scientific and measured their sweat'. He's suggesting they drank according to their thirst, which was dependent on serum osmolality. Which is exactly the point I am making, and exactly the opposite of the point you are making.