Keeping yourself hydrated is especially important when temperatures and humidity are sky high.
Your athletic performance begins to be affected at 1 to 2 percent dehydration—i.e., the loss of 1 to 2 percent of your normal body weight. When dehydration reaches 2 percent, your performance can deteriorate by as much as 40 percent during high-intensity activity.
If you wait until you become thirsty to hydrate, it will be too late. By then, you’re about 3 percent dehydrated, your athletic performance may already be compromised, and you will be at a higher risk for developing cramps and heat illness.
Here are some general guidelines to follow to stay hydrated:
- Drink at least eight 6- to 8-ounce glasses of fluid every day.
- Water is the most appropriate fluid if you are participating in an activity lasting less than an hour. For longer periods of exercise, drink fluids that contain sodium and 6-8% of carbohydrates, such as Gatorade.
- Two hours prior to physical activity, drink 16 to 20 ounces of fluid (water or a sports drink). Ten minutes before, drink 4 to 10 ounces.
- Drink 8 to 10 ounces of fluid every 15 to 20 minutes during activity.
- After your activity is finished, drink 24 to 32 ounces of fluid.
- You may actually require more fluids in hot weather, or if you are thirsty or unable to take frequent breaks.
- Fluids should never be restricted during practice.
- The color of your urine is a good indicator of your hydration level. When you are properly hydrated, your urine color will be clear or pale yellow, and the frequency of urination will be approximately once per hour following exercise. Dark yellow urine means you are dehydrated, and your kidneys are working hard to concentrate your urine to keep water in your body.
A more precise way to measure hydration is by weighing yourself each day before and after activity. You should weigh yourself as consistently as possible, wearing the same clothes before and after. It’s best to weigh yourself after urinating. For every pound you lose during your workout, drink 16 to 18 ounces of fluid.
If you’ve had issues with dehydration and heat illness in the past, be extra careful. You may be more at risk to repeat those conditions.
Athletes who are overweight, deconditioned and sweat more than others are at increased risk for dehydration.