Diet and Nutrition- the importance of water and hydration to your diet

On average, an individual should drink approximately 96 ounces (three quarts) of water per day. Those participating in a fat-loss program should drink an additional eight ounces of water for every 25 pounds they carry above their ideal athletic weight. Water intake should also be increased if the individual is exercising briskly or residing in a hot climate. 

The Importance of Water 

Water is the soup of life. It constitutes approximately 60 percent of the adult human body by weight. Whereas deficiencies in your diet of nutrients such as the macronutrients, vitamins and minerals may take weeks or even years to develop, one can only survive for a few days without water.
Consuming an adequate amount of water will benefit the body in the following ways: 

• Endocrine-gland function improves.
• Fluid retention is alleviated.
• Liver functions improve, increasing the percentage of fat used for energy purposes.
• Natural thirst returns.
• Appetite decreases significantly.
• Metabolic functions improve.
• Nutrients are distributed throughout the body.
• Body-temperature regulation improves.
• Blood volume is maintained.

Water and Performance

The importance of proper hydration cannot be stressed enough. The body cannot adapt to dehydration, which impairs every physiological function. The table below shows the effects of dehydration.

Studies have shown that a fluid loss of even two percent of body weight will adversely affect circulatory functions and decrease performance levels. However, if a fairly regular daily pattern of exercise and water and food consumption is followed, average body weight will provide a very good index of the body’s state of hydration. Realizing this, the organizers of certain ultra-distance running events make it mandatory for competitors to weigh themselves at stations along the course and require each runner to consume enough fluid to regain a predetermined body weight before being allowed to continue.

Thirst alone is a poor indicator of how much water is needed. Athletes consistently consume inadequate fluid, managing to replace approximately 50 percent of sweat losses. A good way to keep track of how much one needs to drink is to first determine his or her average daily weight (e.g., weigh upon waking). Use this number as the standard for the person’s euhydrated (normal) state. Don’t begin a practice session or endurance competition until the body is at, or slightly above, its standard weight. Drink enough water, juice or sports drinks during exercise in order to maintain the starting weight.

Guidelines for Fluid Replacement in the Athlete

• Consume 16 oz. of fluid two hours prior to exercise. An additional 8-16 oz. may be needed if exercising in warmer weather.
• Drink 20-40 oz. of fluid for every hour of exercise.
• Fluids should be cold due to more rapid gastric emptying.
• If exercise exceeds 60 minutes, use of a sports drink (containing up to eight percent carbohydrate) can replace both fluid and dwindling muscle-glycogen stores.
• When exercising for less than 60 minutes, water is the experts' choice for fluid replacement.
• The goal is to replace sweat and urine losses.
• Ingest 20 oz. of fluid for every pound of body weight lost after an exercise bout, especially if rapid rehydration is necessary, as in two-a-day training.

Effects of Dehydration

• Decreased blood volume
• Decreased performance
• Decreased blood pressure
• Decreased sweat rate
• Increased core temperature
• Water retention
• Increased heart rate
• Sodium retention
• Decreased cardiac output
• Decreased blood flow to the skin
• Increased perceived exertion
• Increased use of muscle glycogen

Get some basic education on our other diet and nutrition pages.

• Carbohydrates
• Lipids
• Proteins
• Supplements