Approximately 60 percent of your entire body is made up of water, according to the U.S. Geological Survey. Certain tissues such as muscle, brain and lungs have even more total water. Dehydration can inhibit normal body function, especially during exercise. If you are a runner, fluids are essential to performance. During your run, even a moderate one, you could lose enough water that you compromise function. Act to prevent dehydration, rather than treat it.
General Fluid Recommendations
In the past, you were advised to consume 64 ounces of fluids each day to maintain hydration. However, it now appears that this amount of fluids is too little. In 2004, the Food and Nutrition Board released new water intake guidelines for adult men and women. Men are advised to consume 3.7 liters or 125 ounces of water each day, while women should consume 2.7 liters or 91 ounces per day. Get your water from both food and beverages.
Running and Water Intake
You can lose from 1 to 4 pounds of water through sweating in one hour of high-intensity exercise such as running, according to Nancy Clark, MS, RD. The guidelines for intake cover what you need outside of exercise, but a moderate runner needs to consume more. Two to three hours before your workout consume 17 to 20 ounces of water. Drink 8 ounces 20 to 30 minutes before exercise. Drink 7 to 10 ounces every 20 minutes during your run. Consume 8 ounces about 30 minutes after you complete your run. If you sweat a lot, you should drink to replace lost fluids. Drink 16 to 24 ounces for every pound lost through sweating.
Electrolytes
The major electrolytes that are lost through sweat are sodium chloride and potassium. These electrolytes work to balance the fluids in your body and work during muscular contraction. If your run is longer than one hour and you sweat profusely, you may need to consume a sports drink that replaces lost electrolytes to maintain proper function. If your runs are short and you do not sweat excessively, you can usually get enough sodium and potassium in your diet.
Signs of Dehydration
If you are thirsty or your urine is dark in color and you don't urinate often, you are already showing signs of dehydration. During exercise you may feel fatigued or warmer than usual. If dehydration continues your body temperature rises and can lead to heat exhaustion or heat stroke. Dehydration of as little as 3 to 5 percent can cause cardiovascular strain and an impaired ability to dissipate heat, according to the National Strength and Conditioning Association. Work to prevent dehydration and don't run if you are.
References
- U.S. Geological Survey: The Water In You
- "Nancy Clark's Sports Nutrition Guidebook"; Nancy Clark, MS, RD; 2008
- American Council on Exercise: Healthy Hydration
- "Essentials of Strength Training and Conditioning"; National Strength and Conditioning Association; 2008
Member Comments