Water has several essential roles that it plays in our daily lives. Water is present in all tissues of our bodies. Our blood is 92 percent water; muscles and brain are 75 percent water; our bones are 25 percent water. We need it to regulate our body temperature. When a person is too hot, the body sweats. When sweat evaporates, it lowers the body temperature. Water helps the body absorb nutrients and then carry nutrients and oxygen to all cells in the body. It moistens oxygen for breathing. Did you know that our lungs need approximately 2 glasses (16 ounces) of water a day to function properly? It protects and cushions our vital organs and joints. It also carries waste products from our body tissues and fluids, such as urea and lactic acid which can be toxic if not removed. Water is a preferred beverage choice because it is readily accessible; contains no calories, fat, or cholesterol; and is low in sodium.
How much water do you need?
The body can survive for up to 6 weeks without food but it can last only 1 week without water. The Dietary Reference Intake (DRI) for water was released in 2004. According to the DRI, the majority of healthy people can adequately meet their daily water needs by letting thirst be their guide; however, some groups cannot rely on thirst to maintain adequate hydration— specifically athletes and older adults.
Athletes or physically active individuals have elevated water requirements. Additional water is needed to provide a medium for reactions to release energy, transport nutrients, cool the body, lubricate joints, and remove waste products.
In the case of older adults, water needs are not increased. Older adults are at risk for dehydration because their thirst mechanism may not be working optimally, and some voluntarily abstain from drinking due to concerns about incontinence.
Healthy individuals need approximately 10 to 15 cups of water each day. About 80 percent (8 to 12 cups) comes from drinking water and other beverages, including caffeinated beverages. Most recent research suggests that caffeine does not consistently cause fluid loss (diuresis) as previously thought. Therefore, caffeinated beverages do contribute to total fluid intake. The remaining 20 percent (2 to 3 cups) comes from eating foods, such as fruits and vegetables. As much as 70 to 90 percent of some fruits and vegetables are water.
The more active you are the more water you need
Feeling thirsty is more than a simple signal that your body needs water. Thirst is actually one of the first signs of dehydration. Research suggests that thirst will only replace 50 to 70 percent of actual fluid needs in physically active individuals. As a rule, 4 to 6 ounces of water should be consumed every 10 to 15 minutes of activity. In addition, weight should be monitored before and after activity; consume 3 cups of water for every pound of weight lost during activity. Water is the best fluid for activities lasting less than 60 minutes of continuous duration. For activities lasting longer than 60 minutes, a fluid replacement drink that contains carbohydrate, sodium, and potassium should be used.
The following guidelines should be followed to ensure adequate replacement of fluids lost due to exercise:
• 2-3 hours prior to exercise, drink 17-22 ounces of fluid
• 10-15 minutes prior to exercise, drink 6-10 ounces of fluid
• Every 10-15 minutes during exercise, drink 6-10 ounces of fluid
• Replace every pound lost during exercise with 3 cups of fluid
Source: /Publications/PM1813.pdf
Call me at the Webster County Extension Office, 515-576-2119 with your nutrition and health questions.