You’ve heard it before - your body is about 60% water. So what? Well, nearly every major system in your body depends on an adequate supply of water. Regulating body temperature, flushing out toxins, lessening the burden on your kidneys, and even maintaining normal bowel movements are all body functions that depend on water to work properly. There are tons more but you get the idea. 
Okay, how much should I drink?
- Remember that old 8 cups of water rule? Turns out it’s pretty close. The Institute of Medicine determined that an adequate intake is about 9 cups of fluid for women and 13 cups for men, but that number includes all the beverages you drink during the day. 
That sounds like a lot! How do I drink that much each day?
- If you drink 3-4 cups of water when you get up in the morning, you give yourself the best chance of starting the day off hydrated and remaining that way. Drink this before you even eat breakfast and you will combat dehydration from your night’s sleep and will start your day feeling awake and refreshed.
- Have a drink or two with lunch and dinner and you are well on your way to being adequately hydrated. Stick a bottle of water on your desk and sip it throughout the day.
- Finally, keep in mind that any other beverages you drink also count for your daily intake!
What about coffee? Doesn’t that dehydrate me?
- As long as you’re staying under the equivalent of four cups of coffee per day, the water in your coffee or tea actually outweighs the dehydrating effects of the caffeine.  A cup of coffee is not the best way to hydrate, but you can add it to your daily total in good conscience.
What about exercise and the weather?
- Exercising and temperature make things a little more complicated. In general, it's best to start hydrating the day before strenuous exercise. You should keep drinking up until you work out, with about 1-3 cups of water beforehand. It’s a good idea to have small sips over longer periods of time because chugging can cause uncomfortable bloating.
- When it’s hot or humid out, you need to drink additional water to help lower your body temperature and replace what you have lost through sweating.
- If you are sick, you need to be especially proactive about getting more water than your thirst gauge tells you. Start drinking extra water or an oral rehydration solution at the first signs of illness — don't wait until dehydration occurs. 
Are sports drinks okay?
- The Mayo Clinic suggests that if you are exercising for less than an hour, water is the best way to replace lost fluids. The bottom line is that sports drinks are just extra calories for most people. However, if you are exercising for more than an hour, a sports drink can help to rebalance your electrolytes and give you some energy from added carbohydrates. 
How can I check how dehydrated I am?
- One of the easiest ways to gauge hydration is by checking the color of your urine. If you’re hydrated, your urine will be an almost clear, pale yellow. The darker your urine, the more dehydrated you are.
- Check your urine throughout the day and compare it to this chart to see how you are doing. Keep in mind that toilet water can dilute your urine color to appear clearer than it actually is.
Note: Certain vitamins and medications can change your urine’s color. You can learn a lot from checking your urine, but you can learn a lot more from sophisticated urinalysis that you should get with your regular physical examination.