Can you tell me what can happen if you don’t drink enough water during this summer heat?

The bottom line is 55 percent to 75 percent of the body’s weight is water: The brain is 70 percent water; blood is 82 percent water; and the lungs are nearly 90 percent water. This refreshing liquid carries nutrients and oxygen to cells; cushions organs, tissue, bones and joints; removes wastes; and regulates body temperature.

Excessive water loss, called dehydration, can impair body function and lead to heat exhaustion and/or heat stroke that can be life-threatening.

Water is lost through perspiration and elimination. In high heat, humidity or times of high activity like working outdoors or participating in athletic activities perspiration, which cools the body through evaporation of fluids, increases. Exposure to the sun or a sunburn can speed fluid loss, so can beverages with caffeine, which acts as a diuretic.

Fluid replacement is essential, but it’s best not to wait until you’re thirsty. People often become slightly dehydrated before they become thirsty.

According to Mary Higgins, K-State Research and Extension nutrition specialist, checking to see if your body is well hydrated is easy just look at your urine. If urine is pale yellow in color, fluids would appear to be adequate. If urine is dark yellow or appears concentrated, more fluids are needed.

How much and what type of fluids are recommended each day?

Eight to 12 cups of fluid are recommended each day to replenish essential body fluids. Water is recommended as a majority of the fluid replacement because it is readily absorbed. Cool water is preferred because it is absorbed more readily than warm, hot or ice water.

Some fluid replacement can come from other sources, such as milk; 100 percent fruit juice; low-sodium vegetable juice; foods that have a high water content, such as melons and other fruits and vegetables like celery or tomatoes; or foods made with fluids, such as puddings, gelatin salads or soups.

Beverages that contain caffeine, such as coffee, tea and some soft drinks, or alcohol, which acts as a diuretic and speeds fluid loss, are not recommended as essential fluid replacements. It is suggested that only half of the amounts of these beverages be counted toward total fluid replacement.

Sports beverages may be helpful to some athletes who are exercising more than one hour and in need of quick energy, but our nutrition specialist recommends diluting them with an equal part of water to help replenish fluids and reduce calories. Sugary beverages like sports drinks or carbonated beverages can add unnecessary calories.

Who is most at risk if they don’t drink enough fluid?

Replenishing fluids is recommended for everyone. Before working in the heat, exercising or participating in athletics, it is recommended to drink from 14 to 22 ounces of cool water. It is also advisable to drink from 1 to 1 1/2 cups of water every 15-20 minutes during exertion. Children should be encouraged to take frequent water breaks, drinking about one-half cup after each 15 minutes of activity.

Older adults also need to drink fluids, even if they are not thirsty. The ability to sense thirst declines over the years, so older people cannot rely on their thirst to prompt them to drink enough fluids. The ability to regulate body temperature also declines with age.

If a caregiver is thirsty, a dependent older adult, infant or small child probably is, too. Hold a glass of water or other nourishing liquid up to them when offering a drink.

What about sports drinks?

According to K-State Extension nutrition specialists, water will remain the No. 1 choice for rehydration, with few exceptions. Water is absorbed quickly and works well for most recreational athletes, especially in combination with an appropriate diet.

Sports drinks may be beneficial if an athlete is running a marathon, competing in a triathlon, or participating in some high-intensity endurance event that lasts longer than 90 minutes. A drink with a small amount of sugar might improve stamina. Unlike sugar taken before exercise, which could result in blood sugar dips, sugar taken during exercise can enhance performance because the body does not secrete insulin during exercise.

The best time to drink sports-type fluid replacers is during exercise, not 20 to 45 minutes before the event, when they might trigger a hypoglycemic reaction. It also is not advised to drink sports drinks after a lengthy endurance event, because muscles need full-strength, carbohydrate-rich beverages to replace the glycogen burned during the event and the minerals lost in sweat.

Are there any recipes out there for homemade sports drinks?

The following recipe, found in Nancy Clark’s “Sports Nutrition Guidebook,” has a nutritional profile similar to commercial sports drinks:

Homemade Sports Drink

Yield: 1 quart

4 tablespoons sugar

1/4 teaspoon salt

1/4 cup boiling water

1/4 cup orange juice (not concentrate) or 2 tablespoons lemon juice

3 3/4 cups cold water

In the bottom of a pitcher, dissolve the sugar and salt in the hot water. Add the juice and remaining water; chill.

Nutrition Information per 8 ounces: 55 calories, 14 grams carbohydrates, 154 mgs. sodium, 30 mgs. potassium.

Susan Krumm is an Extension agent in family and consumer sciences with K-State Research and Extension-Douglas County, 2110 Harper St. She can be reached at 843-7058.