Are you ready for the current word on how much water to drink every day?

by Stephanie Atwood, M.A. CHNRC
#3 BFFB#1

In order to stay hydrated, we should drink 8 glasses of water a day.

But does this mean an 8 oz glass or a 20 oz bottle? Drinking enough liquid, but not too much is the secret! Adequate hydration is pretty simple but many of us ignore its importance to our overall good health.

How much water should you drink? What is adequate hydration?

For the average person on an average day, 8 glasses of 8 ounces of water is what your doctor might tell you. This comes out to 64 ounces total, or 2 quarts. Another common measurement is to drink half of your body weight in ounces of water. For a 140 pound woman this would be 70 ounces of water, slightly more than 2 quarts.

However, when you add in an active day where temperatures are high and you sweat because you are exercising, your need for water can be dramatically higher. In this case, drinking water keeps your core body temperature at a healthy level, battling the fact that you are raising it through exercise and exposure to high ambient air temperatures.

Two other factors for consideration:

1.  Micro nutrients (in the form of electrolytes) are necessary to keep your body in balance. When you sweat you lose salt and other micro-nutrients that are essential for your body to function properly. A drink with salt and other electrolytes is an important part of a workout. Natural drinks like coconut water or fruit infused waters, with some salt added, will help to keep you in balance. Beware of sugar drinks however, as they add calories (extra energy) and, if those calories are not needed, they’ll get stored as fat.

2.  It’s possible to drink too much water. This is called hyponatremia and is related to an excess of water and not enough salt in the blood! For long distance trainees and racers, this often occurs with slower racers who are overweight. The combination of excess fat and many hours on a course can create a dangerous “bloating effect”. Water is going into the body but that body does not sweat well and retains excess liquid, causing a dilution that can be deadly.

Thus, my qualifier for drinking water is: drink about half of your IDEAL body weight in ounces of water PLUS some more, based on air temperature and level of exertion. A marathoner who takes 7 hours to complete 26.2 miles may not need a whole lot more water than the 3 hour marathoner due to a lesser level of exertion and a lower sweat rate because the body is not being heated as intensely. Slower marathoners often sweat less, even though they are out dramatically longer.

Want to check your sweat rate? Weigh yourself before a long workout (at least 60 minutes of exercise). Keep track of how much water you consume during your workout. Weigh yourself after your workout. Subtract how much water you drank during the workout. What is the difference in your weight between pre and post workout? Let’s say it is one pound (16 ounces). For a 2-hour workout, divide 16 ounces by 2 and your hourly sweat rate is 8 ounces per hour.

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