How much do you really need to drink when you exercise?

Proper hydration is an often overlooked but essential component of athletic performance. Even a 5% reduction in body fluids can cause a drop in endurance, reaction time and concentration.

As an athlete, knowing the proper way to hydrate can help you maintain your optimal levels of performance.

How much do you need to drink?

The level of activity, environmental conditions (heat, humidity, wind etc.) and your rate of sweat all need to be considered when determining your hydration before, during and after exercise.

The American College of Sports Medicine recommends you know your weight before an intensive exercise session. During exercise, you’ll lose body weight in the form of fluids. After exercise, you’ll need to replace those fluids.

The ACSM offers these general guidelines for exercise/sports hydration:

• About four hours before you exercise: Drink 16-20 fluid ounces of water or sports beverage.
• 10-15 minutes before you exercise: Drink 8-12 fluid ounces of water.
• If you’re exercising less than 60 minutes: Drink 3-8 fluid ounces of water every 15-20 minutes.
• If you’re exercising more than 60 minutes: Drink 3-8 fluid ounces of a sports beverage every 15-20 minutes. A sports beverage is formulated to replace nutrients your body needs.
• Within 2 hours after exercise: Drink at least 8 fluid ounces every 15-20 minutes, or drink 20-24 fluid ounces for every one pound of body weight you’ve lost.

What should you drink?

Research has shown both water and sport drinks are excellent sources for maintaining proper hydration.

Water is just as effective as sport drinks in sustaining performance levels for shorter workouts.

Certain sport drinks contain 6-8% carbohydrates. Research shows this amount of carbohydrates is more effective than drinking water alone in maintaining performance levels for sessions lasting longer than an hour. Sports drinks that contain 6-8% carbohydrates tend to be less upsetting to the stomach and are quickly absorbed by your body to accelerate rehydration.

How do you know if you’re well hydrated?

An easy way to decide if you need of fluids is to check the color of your urine. If the color is pale yellow or clear, you’re well hydrated.

If the color is darker than pale yellow, you’re probably dehydrated.

Do not rely solely on thirst as an indicator of dehydration — thirst is your body’s emergency warning signal. By the time you’re thirsty, you’re already dehydrated. And once you’ve quenched your thirst, you still may not be fully re-hydrated.

Are you watching your weight? Take a free online quiz to learn more about your healthy weight range.

Marissa Strehlow is an athletic trainer at Aurora Sports Health in Mequon, WI.