Our bodies are made up of about 60% water, and every system depends on water. So water is important for healthy skin, hair, and nails, as well as controlling body temperature, heart rate, and blood pressure.
"It's definitely essential," says Jim White, registered dietitian and personal trainer in Virginia Beach, Va., and American Dietetic Association spokesman.
You can stay fully hydrated throughout the day by drinking water and other fluids, as well as eating foods that are hydrating.
What Counts as Water?
Fruits are an excellent source for water. Watermelon is 90% water, so it ranks highest on the list. Oranges, grapefruit, and melons like cantaloupe and honeydew are also strong contenders.
Vegetables, though not as full of water as fruit, can also provide a nutrient-rich water source. Stick with celery, cucumbers, tomatoes, green peppers, and Romaine lettuce.
There are plenty of hidden sources of water in your diet, says White. If you want to tap into these foods, reach for oatmeal, yogurt, soup, and smoothies.
Besides guzzling water, milk is a top choice to refuel. Sodas, even diet ones, get a bad rap for lacking nutritional value, but they can still be hydrating. Juices and sports drinks are also hydrating -- you can lower the sugar content by diluting them with water.
Coffee and tea also count in your tally. Many used to believe that they were dehydrating, but that myth has been debunked. The diuretic effect does not offset hydration.
Alcohol is a huge dehydrator, says White. You should try to limit your intake, but if you are going to raise a glass, aim for at least a one-to-one ratio with water.
If you don't like the taste of plain water, White suggests adding lemon to it. Or test out your own concoction, like sparkling water with raspberries with a sprig of mint.
How Much Water Should I Drink?
Parents should make sure that children and teens are getting adequate hydration throughout the day. The American Academy of Pediatrics recommends that children drink plenty of fluids before starting any exercise and continue to drink during physical activity.
During exercise, the AAP suggests drinking about 3-8 ounces of water every 20 minutes for children 9-12 and about 34-50 ounces per hour for adolescent boys and girls.
Athletes need to take precautions to avoid dehydration. White recommends drinking 16 ounces one hour prior to exercise, 4-8 ounces every 15 minutes during exercise, and another 16 ounces an hour after exercise. The amounts can vary depending on your personal response, heat index, and the type of activity.
"If you're sweating, you're losing water," says Nancy Clark, MS, RD, sports dietitian in Chestnut Hill, Mass., and author of Nancy Clark's Sports Nutrition Guidebook.
How can you tell if you're getting enough fluids during the day? You can tell by checking your urine color and output. If you're urinating every two to four hours, the output is light-colored, and there's significant volume, then you're probably well-hydrated.
"That's a very simple, easy way to monitor hydration," says Clark. "If you go from 8 in the morning until 4 in the afternoon without peeing, then you're dehydrated."
Signs of Dehydration
How can you tell if you're dehydrated? You might feel tired, cranky, moody, or get a headache. "As the body gets dehydrated, the heart has to work harder to pump blood through the vessels," explains Clark.
To get a better handle on your hydration levels, White recommends keeping a water log. "Everyone tracks food. How often do we track our water intake?" he asks.
For techie types, there are free apps that pop up with water reminders throughout the day. Whatever method works best for you, drink up and stay well hydrated.