Here are a few symptoms i have experienced as i start to get dehydrated:
1. What little running form i have completely deteriorates. It's really hard to tell when you're weaving, but by the time you are weaving enough that you become aware of it, you're about to go down. If you are having trouble keeping a consistent stride, you could be dehydrated. (there could also be a rock in your shoe, but drinking some more water is still not a bad idea.)
2. Your mouth feels sticky, like when you wake up. When you are dehydrated, your mouth can feel dry and parched, but it can also feel sticky, like your saliva has become very thick. If you try to spit, it will end up all over your face and that is not cool. drink some water.
3. First you sweat, which is gross, but all that sweat is cooling you off. If you stop sweating, thats when you should be concerned. I find that i get a nice think layer of salt all over my face and arms. God i am sexy.
|your face should NOT look like this.|
5. The best indicator for me is if i finish a long run, and go home and immediately fall asleep. Its normal to be tired, especially if it is a new distance for you, but if you are unable to even feed yourself and shower, you are probably dehydrated.
That said, the best way to stay hydrated on a run is to either carry water with you, or make frequent stops. (I carry a water bottle on runs longer than 10 miles, or if its really hot, or i know there is no water anywhere. I like to take frequent little sips as i'm running, rather than stop for larger amounts.) Another thing i found is the Gu Brew! Its basically a flavored electrolyte tab. There are a lot of different companies making similar products, but the gu brew is my favorite. They don't sponsor me, this is just my tastebuds talking. I am sure they all work effectively, but i really like the flavor of the gu brew. Its like gatorade, only lighter, and a little fizzy. It's my new favorite post run drink! I have yet to take it out with me on the run, seeing as how i have been doing low mileage all month, and it's so cold i haven't been sweating much, but i am kind of excited for a rematch with summer distance running! IT'S ON!
When it comes to hydration, only you know what you need, just make sure you always have access to what you need. Or at the very least, if you collapse, don't let it affect your time....