Hi, I'm Marty Beene, and I'm here to talk about how to hydrate three days before a big race or even a particularly challenging run. Hydration is one of the most important parts of running, because your body needs to cool itself down, and it does that by sweating. Sweating is transferring water out to your skin. You really need to hydrate all the time, even when you're not running. Your body is actually losing water all the time through respiration and even perspiration that you may not notice. When you run, you lose water much, much faster, so you need to be hydrating in order to support that. Whether it's three days before running your big event or just before any run, there are a lot of things you should be doing. You should be drinking a little bit of water all the time. How much should you be drinking? It's hard to say exactly how much water, because the water needs for a person who's say six foot two and 200 pounds is very different from a person who's five foot two and 100 pounds. Also, the weather conditions and the distance that you're going to run may be very different. I usually advise people to watch for two things. You should be urinating about every half an hour to an hour. For my high school student athletes, I just tell them, if you're not having to pee between every class change, then you're not drinking enough. If you have a major running event planned, like a marathon, it's very important to be completely hydrating three days or more before that. You don't want to put unnecessary stress on your body leading up to the big event.