Water is essential for human survival. An adult body is made up of about 60 percent water, and a newborn is made up of 74 percent of water. Water removes waste from cells, brings nutrients to cells, regulates body temperature and helps you digest food. When you don't consume enough water, serious complications can arise. Your hydration needs depend on exercise, diet, age, body fat, altitude, pregnancy, medications and the weather.
The average amount of water consumed for males and females is based on caloric intake. In general, you need 1 to 1.5 milliliters of water per calorie consumed each day. On average, a female needs 9 cups of water per day, and males need 13 cups per day. During the second trimester of pregnancy, women should increase their calorie intake, which in turn increases their water needs. Pregnant women should get 8 to 10 glasses of water each day to account for higher blood volume, circulation for the fetus and amniotic fluid.
Plain water isn't usually necessary for infants, who get proper hydration whether they are breastfed or formula-fed. Infants are prone to dehydration because of their age, but increasing the amount of breast milk or formula may help. In extreme cases, intravenous fluids may be needed.
Exercising increases your hydration needs. Exercise and improper hydration, as well as clothing, weather and exercise intensity, can affect the balance of electrolytes in your body. Before exercising, make sure you are properly hydrated. Drink about 20 ounces of water two hours before a workout. Drink 3 to 8 ounces of water every 15 minutes during exercise sessions. If exercising longer than an hour, drink a solution with carbohydrates and salt to increase fluid absorption and regulate blood sugar.
Hot weather raises your requirement for fluids whether you're exercising or not. Drink fluids even when you aren't thirsty to ensure hydration. When you're intensely exercising in hot weather, drink two to four glasses of water during the session, and include fluids with carbohydrates and salts. Caffeinated drinks, alcohol and heavily sugared drinks do not count as hydrating.
Dehydration is very serious and can affect your heart and body temperature, cause fatigue and possibly result in death. Children, elderly people and ill people are more prone to dehydration. Symptoms of dehydration include dry mouth, fatigue, increased heart rate and decreased urine output.