I was reading an article (which I can no longer find), and came across a tip about not relying on thirst to determine when to hydrate yourself. This is something I have heard time and again throughout my competitive running days, and it bears repeating.
Hydrating yourself while working out is very important because your muscles need water to function at peak efficiency. The adage goes, “Don’t wait until you are thirsty to start drinking, because by then it is too late.” Your body doesn’t know that it is going to run out of water until after you will not have a chance to recover, especially if you are in the middle of your workout or race. By continuously hydrating as you go along, you avoid getting thirsty in the first place, and you provide your muscles with some of the fuel they require to work.
A quick and dirty way to find out if you are hydrated is to inspect the color of your urine. A very deep yellow color means that your body is retaining fluid due to being underhydrated. It is dark because the urine is concentrated. If it is the color of straw then you should be in good shape; if it looks like water then you are probably okay as long as you are not overhydrated (I will discuss my thoughts on hyponatremia later).
In a road or track race, there are frequently water stations where you can get cups of water while you are running by. I recommend drinking the water rather than dumping it over your head. You will cool off much better by rehydrating yourself. If you can, grab two cups and ingest one and dump the other, if you prefer, but try to at least drink some of the water.