Running in the good old days used to be uncomplicated and simple.
Some people remember runners before going out running with nothing with them.
After a time, they come back and drink their water.

Drinking (or hydration) was not such a big deal before.
Today, there are some runners who carry their own water and enough gadgets
to monitor their exact intake during a run or a race.
http://goodhealthandfitnessnetwork.blogspot.com/