You need water to regulate body temperature and to provide the means for nutrients to travel to your organs and tissues. Water also helps transport oxygen to your cells, removes waste and protects your joints and organs.
Dehydration occurs when you lose more water than you take in. You lose water through urination, respiration, and by sweating, and you lose more water when you're active than when you're sedentary.
Diuretics, such as caffeine pills, certain medications and alcohol may increase the amount of water your body loses. Lost fluids must be replaced by the fluids in the foods you eat and the beverages you drink.
Symptoms of mild dehydration include thirst, pains in joints and muscles, headaches and constipation. A strong odor to your urine, along with a yellow or amber color, may also indicate dehydration.
Note: riboflavin, a B vitamin, will make your urine bright yellow when you take dietary supplements that contain large amounts of riboflavin. Certain medications can change the color of urine, as well.
How Much Water Do I Need?
The foods you eat supply about 20 percent of the water you need. The rest comes from the beverages you drink. One method of determining your need for water is by taking your weight in pounds and dividing that number in half. This gives you approximately the number of ounces you should drink each day.
For example, if you weigh 160 pounds, you might want to drink at least 80 ounces of water or other fluids per day.
My hydration calculator can help you determine how much water you need to drink each day. It also takes your activity levels, altitude and other factors into consideration.
Water is probably the best choice for hydration because it's cheap and has no calories or added ingredients. Sweetened soft drinks and sodas have extra sugar but no additional nutritional value.
Sports drinks contain minerals that may help keep your electrolytes in balance, which is good for recovering after a hard workout, but look out for added sugar and calories that you may not want.
Fruit and vegetable juices have vitamins and minerals, but read the labels because most vegetable juices are high in sodium.
Caffeinated beverages like tea and coffee count too, but too much caffeine can make you feel jittery.
Armstrong LE, Pumerantz AC, Roti MW, Judelson DA, Watson G, Dias JC, Sokmen B, Casa DJ, Maresh CM, Lieberman H, Kellogg M. "Fluid, electrolyte, and renal indices of hydration during 11 days of controlled caffeine consumption." Int J Sport Nutr Exerc Metab. 2005 Jun;15(3):252-65.
Institute of Medicine of the National Academies. "Dietary Reference Intakes: Water, Potassium, Sodium, Chloride, and Sulfate." Accessed March 15, 2007. .
Spigt MG, Kuijper EC, Schayck CP, Troost J, Knipschild PG, Linssen VM, Knottnerus JA. "Increasing the daily water intake for the prophylactic treatment of headache: a pilot trial." Eur J Neurol. 2005 Sep;12(9):715-8.