A sip of cool, clean water during the warm summer months is not just refreshing — it’s essential. As we learned during elementary school health class, our bodies are 60 to 70 percent water, and that water is doing some important things for our health.

Water keeps us cool, helps with digestion, distributes nutrients throughout the body, energizes the muscles, helps remove toxins, and keeps our skin looking good. It also aids in athletic performance, making the water bottle one of the most important tools in the arsenal of both serious athletes and weekend warriors.

“Hydration is important because the body is comprised mostly of water, and the proper balance between water and electrolytes in our bodies really determines how most of our systems function, including nerves and muscles,” said Larry Kenney, PhD, a professor of physiology and kinesiology at Penn State.

But whether you’re an athlete or not — regardless of whether your typical summer day is spent on a bike, on a golf course, in the garden, or in a hammock — good hydration remains one of your most essential components to achieving optimal health. In this spirit, here are eight facts you may not know about water, hydration, and health:

Water & Hydration1. Drink eight glasses of water per day? Perhaps.
Our mothers told us we need to drink just eight glasses of water a day, right? Not so fast. Medical researchers are quick to point out that hydration needs vary from person to person and are dependent upon all sorts of factors, from weight and gender to your personal level of activity.

But if you need a number, start with advice from the Institute of Medicine, which recommends men drink 3 liters and women drink 2.2 liters of water a day. This is just a starting point, however. Listen to your body and let it guide you the rest of the way.

2. If you feel thirsty, you’re already dehydrated … slightly.
Thirst is your brain’s way of telling you you’re not drinking enough water. As such, when you’re thirsty, you’re already slightly dehydrated, meaning your body is low on the water is needs to function properly. One of the factors responsible for thirst, after all, is an increased concentration of particles in the blood, a concentration due to the reduction of water in your body.

3. Thirst is only one indicator of thirst.
A decrease in your body’s water levels by just a couple of percentage points can lead you to experience such signs as fatigue, headaches, dry mouth and the lack of clear thinking. The color of your urine is also an accurate determinant of your level of hydration. Your urine should remain a slight yellow color; any darker, and you should grab a glass of water … or three.

4. Our sense of thirst comes and goes with age.
That’s right – our age giveth, and our age taketh away.

Children, for instance, have an underdeveloped sense of thirst. Throw in the fact that kids exhibit high levels of energy, and this combination makes them susceptible to dehydration. Ditto with older adults. While generally less active, seniors experience a less acute thirst mechanism as they age, also putting them at greater risk for dehydration.

5. You can eat to hydrate.
While you will certainly drink most of the water you need each day, you may be surprised by how much water your body can glean from the food you eat. Fresh fruits such as apples, peaches, berries and melons boast especially high water content, with water making up from 80 to 90 percent of the weight.

“You don’t have to drink water per se to get water, you can eat watery foods and that will count,” says Nancy Clark, a registered dietitian and sports nutritionist in Boston. “Soup counts, yogurt and watermelon count. An orange is 90 percent water, salads are a lot of water; so all in all, people get plenty of water through foods and beverages other than water.”

6. Hydration is critical for the heart.
Keeping the body hydrated helps the heart more easily pump blood through the blood vessels to the muscles. It also helps the muscles remove waste so they can work efficiently, the American Heart Association reminds us.

“If you’re well hydrated, your heart doesn’t have to work as hard,” said John Batson, M.D, an American Heart Association volunteer and a sports medicine physician with Lowcountry Spine & Sport in Hilton Head Island, S.C.

A study published in the American Journal of Epidemiology in 2002 found that those who drink more than five glasses of water per day were 41 percent less likely to die from a heart attack during the study period than those who drank less than two glasses.

7. Hydration is critical for the rest of the body, too.
Every system of the body — every cell of every organ — requires water in order to function properly.

At the molecular level, water allows for the transport of oxygen and nutrients to your cells as well as the removal and excretion of the waste products of metabolism. On a larger scale, water aids in the removal of toxins from your body, it regulates your body temperature, it aids in digestion, and it keeps your metabolism in good working order.

Studies have also shown that those who remain hydrated are more alert, have more vibrant skin and are more energetic. Some researchers have also linked water consumption with heart disease (see above) and cancer.

8. That morning coffee is good hydration.
Don’t sweat that cup of coffee in the morning. While it’s been widely assumed that drinking coffee and other caffeinated beverages will actually contribute to dehydration, experts today suggest that’s not necessarily the case, says a report by the Institute of Medicine’s Panel of Dietary Reference Intakes for Electrolytes and Water.

“While consumption of beverages containing caffeine and alcohol have been shown in some studies to have diuretic effects,” the report states, “available information indicates that this may be transient in nature, and that such beverages can contribute to total water intake and thus can be used in meeting recommendations for dietary intake of total water.”

So there you go, coffee drinkers. Keep in mind, however, that nothing beats pure water when it comes to hydrating your bodies.

RESOURCES:
Medical News Today: Study Finds Hydration Lacking on Older Adults

Medical News Today: Hydration – Essential for Your Wellbeing

National Center for Health, Physical Activity & Disability: Keeping Hydrated During the Summer Months

Medical Daily: How To Stay Hydrated This Summer

Mayo Clinic: Dehydration

Mayo Clinic: How Much Water Should You Drink Every Day?

Active: 15 Hydration Facts for Athletes

Mind, Body, Green: Hydration Facts You Need to Know

Cleveland Clinic: Avoiding Dehydration; Proper Hydration