|Double-fisting is always an option.|
1) Drinking 5 glasses of water a day reduces your chances of heart attack-- by a lot! Researchers at Loma Linda University discovered that drinking at least 5 glasses of water per day lowers heart attack risk by over 50%. Water reduces the viscosity of the blood, so lots of factors that contribute to coronary disease are lowered by making this small change. See the study here: http://aje.oxfordjournals.org/content/155/9/827.short
2) Even mild dehydration puts the body at risk for several different diseases, from urinary tract infection (which, although isn't usually fatal, is pretty horrific to go through) to venous thromboembolism (such as those blood clots that people can get in their legs from sitting for too long-- these can be deadly) and many diseases in between. For a summary of research on the relation between hydration and several diseases, read this: http://www.jacn.org/cgi/content/full/26/suppl_5/535S
3) Dehydration is linked to decreases in strength and endurance, particularly in hot climates. ( http://www.ncbi.nlm.nih.gov/pubmed/18550960 ) If you want to perform at your peak, you need to drink water before, during, and after exertion, especially on hot days or if you sweat heavily.
4) Considering that the human body is around 60% water, one might see a reason to keep those levels up there.
So, how much water, exactly, should we be drinking? Well, the "8 glasses a day" rule is a good place to start, but everyone's body is different. Some people need more than others. If you have a high-protein diet, ingest a lot of caffeine, sweat a lot, or have diarrhea or vomiting symptoms, you will need to drink more water than usual. Using thirst as a gauge is not a good way to go about drinking water-- being thirsty means you're already going into dehydration status. Your best bet is to make sure you don't get thirsty.
A singing teacher I once had gave me this gem: "If you're a singer, your pee should always be clear." In other words, if you're a singer you should be drinking a lot of water. Nothing like a good pee quote to make a girl happy. I'd take that to another level and say, "If you're a person, your pee should generally be pretty clear." Meaning you should be drinking a lot of water. The darker your pee is, the more concentrated your urine is, and the more dehydrated you are likely to be. So that's always a good gauge.
So, there's my little schpiel on hydration. I plan to stick with my resolution, and all this typing is making me thirsty. I'm gonna go get me some water.
Oh-- and while you're upping your water intake, you'd probably better read this: http://melodyschoenfeld.blogspot.com/2010/12/do-you-know-whats-in-your-water.html
Questions? Comments? Post 'em here!