Water is second to oxygen as a substance needed to sustain life. Water makes up about 60 percent of your total body weight (about 1 and one-half large buckets of water). An adequate supply of water is necessary to help regulate the body temperature; to carry oxygen, hormones, and nutrients to the cells; for electrolyte balance; to cushion joints; to protect inner organs; and for the elimination of waste products. The body loses water through perspiration, exhaled water vapor from the lungs, and excretion of urine.
Each day you need to replace around four percent of your body weight in water. Drinking six to eight glasses of water a day is recommended for health maintenance. However, fruits and vegetables have a high concentration of water and the actual number of glasses needed each day is somewhat less. And individual needs vary according to dietary factors, age, weight, climate and humidity, exercise, and the effectiveness of your body's systems.
The key to keeping your body working efficiently and meeting your personal exercise needs is to take in as much water as you need.
Research studies have determined that the number of ounces of water you need equals your weight divided by two. If you weigh 180 pounds, you need to drink about 90 ounces or 11 cups of water daily. One method of determining if you are getting enough water is to observe the color of your urine; it should be pale yellow.
Another method of determining the amount of water needed daily is to drink a quart of water for every 1,000 calories you consume in your diet. For a 2,500-calorie diet, this would equal a daily count of 2 and one-half quarts (10 cups) of water.
The body loses about a quart of water per hour during exercise. Fifteen minutes prior to exercise, drink approximately two cups of water. During exercise, drink one-half to one cup of water for every 15 minutes of exercise. Weigh yourself before and after exercise. Any weight lost is due to loss of water through perspiration. Drink one to two cups of water for each pound lost during the activity. The best way to replace fluid lost in exercise is with cold water. Cold water will leave the stomach sooner than warm water and help you to cool down rapidly.