"Our bodies are 70% water and even a 2% deficiency can be life-threatening," said Tim Massie, owner of Iron Horse Nutrition in Pleasanton. "It serves as a lubricant, it helps regulate your metabolism, and it's really important for people involved in weight loss."
Proper hydration also leads to clearer skin, a lower risk of disease, more energy and better concentration.
Breaking the body down by vitals organs, the brain is approximately 90% water; blood, 80%; and lungs, 90%.
"So it's not a small part of us," Massie said. "It's huge."
When customers come to him for weight-loss advice, he puts drinking more water on the top of the list.
"The body is actually pretty smart," he explained. "If you don't have enough water, your body will tend to store extra water.
"It's quite common for people that begin to work out to work with a trainer and they always push them to drink more water. They can lose 5 to 10 pounds in the first couple of weeks."
"A lot of that is water weight -- it looks like fat on the body," Massie added. "When you drink more water it can help you to lose weight and lose fat. Lot of times toxins are stored in fat."
Pleasanton tap water will do the trick, Massie said, although his family's water goes through a filter in the refrigerator.
"Coffee, black tea and soda actually work against the body's water total," he said. "If you drink a cup of coffee, you will need to drink 1-1/2 cups of water."
There are extreme cases where people have died from drinking too much water, and going overboard in drinking water is common in endurance athletes, according to a 2007 article in Scientific American.
When working out, weigh yourself before and after, and drink 20-24 ounces of water for every pound lost. It is also important to hydrate several hours before exercise and to drink 8-10 ounces every 15 minutes during exercise.
"I spent 11 years active duty in the military, in Naval Special Operations, and we used to actually, as a leader, force our teams to drink," Massie said. "Sometimes you don't recognize that your body is getting dehydrated."
Urine is a good indicator of proper hydration: A high volume of light-colored urine means you're probably hydrated; and dark-colored, concentrated urine means you're debydrated, as does cramping, low energy or fatigue, brain fog or dizziness.
"If you're out in sun not getting enough water sometimes you're not really focusing on what you're saying, moving into some dizziness, heat exhaustion or even heat stroke," Massie said.
"I was playing golf a couple of years ago with some friends in Las Vegas. We went to a morning golf school and it was nice outside. Then we had lunch, then got a free 18 holes of golf.
"There was nobody out playing golf, the temperature on the course was about 114 degrees," he continued. "There was like a little golf cart with drinks and stuff -- we only played 9 holes -- and I drank a bottle of Gatorade at every hole."
Despite all this hydration, no bathroom break was necessary.
"It was so arid there," Massie said.
Sodas are bad hydration because they contain so much sugar, he noted, or artificial sweeteners. The same is true with juices, which can contain even more sugar.
Although we get a certain amount of hydration from many of the foods we eat, drinking water allows your system to have an abundance of water and to work properly, Massie said.
"It's a pretty easy fix," he said.
For people trying to lose weight, the recommended formula is to divide the body weight in half and drink that many ounces of water. For instance, a 200-pound person should drink 100 ounces of water per day.
If drinking water becomes a chore, water flavorings such as MiO are on the market to give it a slight taste without adding calories, sodium or sugar. Massie brings a half-gallon jug to work everyday and uses enhancers for variety.
"There's not anything bad in them," he said. "It doesn't take much, a couple of drops in a bottle of water."
"When the well is dry, we know the worth of water," Benjamin Franklin wrote in his Poor Richard's Almanac in 1746.
Now, in 2012, we always know its worth: Drink up!
What water does for your body
* Serves as a lubricant
* Helps regulate the metabolism
* Is the base of saliva
* Forms the fluids that surround the joints
* Helps alleviate constipation
* Acts as a detox agent
* Regulates body temperature