Debunking the Water Myth

Did you know that approximately 70% of your muscles are made up of water? It also makes up about 75% of your brain, 22% of your bones, and 83% of your blood. I'm surprised we don't slosh when we walk! Water is vital to our existence. It helps with digestion, helps regulate body temperature, helps the body absorb nutrients, and decreases your chance of getting bladder and colon cancer. Even though I know all of this, hydration is something I have to continuously and consciously work on.

I've always heard the 8 x 8 rule for drinking water each day—8oz of water 8 times a day. I did a little digging and found that several different theories abound on this topic. Some long held myths about water have recently been debunked by researchers. The Mayo Clinic says that the daily water needs vary from person to person. They do mention the popular 8 glasses of water a day recommendation although they say the theory isn't backed up by scientific evidence. The Mayo Clinic does say that if you drink enough fluid so that you rarely feel thirsty and produce 1.5 liters (6.3 cups) or more of colorless or slightly yellow urine a day, your fluid intake is probably adequate. The following video clip from CBS News provides more information on the recent research of daily water requirements for a healthy body.

Anyone doing anything that causes them to sweat (especially runners) need to make sure they are accounting for the extra water loss by drinking more. The extra amount of water will vary from runner to runner depending how much you sweat. The key is knowing your own body and its hydration needs under various conditions. The Sweat Rate Test below can help you to determine your hydration needs. I recommend doing the test several times each under different conditions such as early morning, midday, later afternoon, very hot, hot/humid, etc. This will give you a good idea of how much water you'll need for each kind of condition.

Sweat Rate Test:
1. Weight before running; record the amount

2. Run for 60 minutes

3. Weight after running; record the amount

4. Calculate the difference of the two weights; record the amount

5. Each pound lost = 16oz of fluids

6. Record the temperature and pace of run

The other day I did the sweat rate test on myself and discovered I had lost 2lbs after my run. That's 32oz of water I needed to replace that I had lost during my run. Not only is it important to replace fluids lost, it's just as important to fully hydrate yourself prior to a workout so that you don't become dehydrated during your run. Also, drinking a sports drink throughout the run, especially on hot days, will help to keep you hydrated as well as provide you with the energy to maintain your endurance level throughout the run.