Drink Up!

Quick: What’s the most critical nutrient for growth, development, and health? If you guessed “water,” congratulations! The importance of water in the diet is frequently overlooked, and most people don’t even consider it an essential nutrient. However, without any water or other fluids, you would die within a week.

While water does not provide energy in the same way carbohydrates and fat do, it plays an essential role in energy formation. As the most abundant nutrient in your body, it is the medium in which all energy reactions take place. Thus, you need ample fluids for fuel and stamina. You get those fluids from a variety of sources—the foods you eat, the beverages you consume, and the plain, pure water you drink. Here’s a closer look at the importance of water in your diet.

An essential nutrient. It is hard to say enough good things about water. It makes up about 60 percent of body weight in adults. It is involved in all metabolic processes, carrying nutrients throughout the body and transporting waste products away. It is part of the lubricant fluid in your joints to keep them moving. And when your body’s temperature begins to rise, water acts like the coolant in your radiator.

Water, water everywhere. Nearly all foods you eat contain water, which is absorbed during digestion. Most fruits and vegetables are 75 to 90 percent water. Meats contain roughly 50 to 70 percent water, and beverages such as juice, milk, and sports drinks are more than 85 percent water. On average, you consume about four cups of water daily from food alone.

To keep your body “watered,” you need a bare minimum of eight to 10 cups of pure water daily or about a quart for every 1,000 calories of food you eat—even more to replace the fluids you lose during exercise.

The Temperature Regulator. Your body produces energy for exercise, but only 25 percent of that energy is actually used for mechanical work. The other 75 percent is released as heat. The extra energy produced during exercise causes your body to heat up, raising your core temperature. To get rid of that extra heat, you sweat, which, as it evaporates, cools your blood and body. If you couldn’t cool off, you would quickly succumb to the heat stress caused by the increase in your body’s core temperature.

Water and fat burning. Drinking more water can actually help you stay lean, indirectly. Your kidneys depend on enough water to do their job of filtering waste products from the body. In a water shortage, the kidneys need backup, so they turn to the liver for help. One of the liver’s many functions is mobilizing stored fat for energy. By taking on extra assignments from the kidneys, the liver can’t do its fat-burning job as well. Fat loss is compromised as a result.

Water and exercise performance. Ever wondered why some days you’re so pooped you can’t pump iron? One reason may be dehydration. To move your muscles, you need water. Of all places in your body, water is found in highest concentrations in metabolically active tissues like muscle. Muscles are controlled by nerves, and the action of nerves is dependent upon the exchange of electrolyte minerals dissolved in water across the nerve and muscle cell membranes. Thus if you’re low on water or electrolytes, muscle strength and control are weakened. In fact, a water deficit of just 2 to 4 percent of your body weight can cut your strength-training workout by as much as 21 percent if you are dehydrated—and your aerobic power by a whopping 48 percent. Your body’s thirst mechanism kicks in when you have lost 2 percent of your body weight in water. But by that time, you are already dehydrated. To prevent dehydration, you must get yourself on a scheduled plan to drink often throughout the day.

Are you getting enough? Most people are walking around in a moderately dehydrated state. Add exercise and a warm climate, and you spell dehydration in a big way. What about you? Are you dehydrated? The list below provides some early and severe warning signs of dehydration and heat stress. 

Early Signs Severe Signs Fatigue Loss of appetite Flushed skin Heat intolerance Light-headedness Dark urine with a strong odor Dry cough Difficulty swallowing Stumbling Clumsiness Shriveled skin Sunken eyes and dim vision Painful urination Numb skin Muscle spasm Delirium

Early Signs of Dehydration

Check your urine. It should be light-colored with little odor. If it is a golden color or a deep color with a strong odor, you are dehydrated. Weigh yourself without clothing before and after exercise. For every pound lost during exercise, you have lost about two cups of fluid. Any weight lost during exercise is fluid loss and should be replaced by fluids as soon after exercise as possible. Dehydration is cumulative. Your body can't rehydrate itself. If you fail to rehydrate on consecutive occasions, you will become increasingly dehydrated and begin to suffer from the early symptoms of dehydration. Sore throat, dry cough, and a hoarse voice are all additional signs of dehydration. A burning sensation in your stomach can signal dehydration. Watch for muscle cramps. No one knows for sure what causes muscle cramps, but a shortfall of water may be an important factor. Muscle cramps are more apt to occur if you are doing hard, physical work in the heat without drinking enough fluids. You can usually alleviate cramps by moving to a cool place, drinking fluids, and replacing electrolytes with a sport drink.