Skip to main content

« Back

Water and Your Body

Jan 23, 2012

After oxygen, water is the human body’s most important need. Water carries waste products and toxins from the body, actively participates in many chemical reactions, acts as a lubricant and cushion around joints, serves as a shock absorber inside the eyes and spinal cord, aids in the body’s temperature regulation, and helps maintain blood volume.

Water Protects Your Overall Health

If you do not get enough fluid, you will not feel well. After all, you can live without food for a month, but only a week without water. A common cause of daytime fatigue is inadequate fluid intake. Researchers suspect that 75 percent of Americans have mild, chronic dehydration.

You need water because so much of your makeup is water! The average adult contains 40 to 50 quarts or 10 to 13 gallons of water. Blood is 83 percent water, muscles 75 percent, brain 75 percent, heart 75 percent, bones 22 percent, lungs 86 percent, kidneys 83 percent, and eyes 95 percent.

Clinical studies show that drinking eight glasses of water a day can decrease the risk of colon cancer and bladder cancer, and may reduce the risk of breast cancer. Preliminary research suggests drinking eight to ten glasses of water a day can ease back and joint pain for up to 80 percent of sufferers.

Water Aids in Digestion

Healthy digestion requires adequate fluid intake. The colon is your body’s fluid regulator. If you’re not drinking enough, your colon steals water from the waste material and gives it to the body, causing the stools to be water deprived or hard. These hard, dry stools are difficult to pass, because they stick to the dry wall of the colon.

By drinking plenty of water each day, you help your body stay hydrated enough, so that it doesn’t need to extract much water at all from the solid waste materials that are moving through the colon. Since the waste material keeps its water, it stays soft and pliable so that it’s able to move through the colon at a much easier and faster rate.

One of the important jobs of water is to help your kidneys remove wastes like uric acid, urea, and lactic acid. If you do not have enough water to dissolve the wastes then they cannot be removed effectively and you run the risk of kidney damage.

We dehydrate as we get older. Because the thirst response declines with aging, seniors don’t get as thirsty as younger people and must make an effort to drink water even when not thirsty. To try to fill the basic requirements of one-half to two-thirds of your body weight in ounces of water per day, seniors should remember to sip throughout the day.

Water Intake Guidelines

The gold standard has always been that everybody needs eight glasses a day. That isn’t the best guide. Most people should increase their water consumption, but individual needs vary. Your personal water needs are influenced by your physical activity level; consumption of meat, eggs, or salty foods; fever; heat; or dry, hot, or windy climates.

One way of getting enough fluid is to up your vegetable and fruit intake. Many vegetables are more than 90 percent water, and many other foods, like legumes and grains, are more than 80 percent water after being cooked. Of course, soups and broths are nearly all water.

A basic guideline for how much water you need is to divide your weight in half and then consume that many ounces of water each day. So a 128-pound person needs 64 ounces, but a 160-pound person needs 80 ounces. These guidelines are for total fluid intake, including fluid from all food and beverages. How does your total fluid intake compare?

Prevent Dehydration

By sweating, urinating, and breathing, your body gets rid of about ten cups of fluid a day. When you get rid of fluid, you also dump electrolytes, which are minerals like sodium and calcium that keep your body’s fluids balanced. If you exercise, mow the lawn, or forget to drink as much water as you should (e.g., during a long airplane flight), your body will become dehydrated.

Poor hydration can harm a child’s mental performance and learning ability. Symptoms of mild dehydration may include tiredness, headaches, and a feeling not unlike jet lag, as well as reduced alertness and ability to concentrate. Encourage your child’s school to allow plenty of water breaks, or ideally a personal water bottle at every desk.

Even becoming mildly dehydrated (when you lose as little as 1 percent to 2 percent of your body weight) can seriously impact your body’s ability to function. It is fairly easy to become dehydrated. In fact, by the time you become thirsty, your body is telling you it’s dehydrated!

Mild dehydration signs include:

  • Thirst
  • Flushed face
  • Dry, warm skin
  • Lightheadedness or dizziness made worse when you stand
  • Weakness
  • Cramping in the arms and legs
  • Having few or no tears
  • Headache
  • A lack of energy
  • Dry mouth and tongue with thick saliva


Schedule a complimentary fit evaluation so we can get to know you and your goals and build you a customized training program to reach them.