Proper hydration is crucial to your health and physical ability when it comes to running. The Institute of Medicine advises that all men consume roughly 3 liters (about 13 cups) and all women consume about 2.2 liters (about 9 cups) of fluids per day. In addition, active individuals need to consume more fluids to make up for water lost during exercise. The National Athletic Trainers’ Association recommends drinking 500-600 mL (17-20 oz) of fluids two hours before exercise and 200-300 mL (7-10 oz) of fluids every 10-20 minutes during exercise. For optimal performance, when performing runs that exceed 60 minutes in length, you may want to consider switching to a sports drink that replaces sodium and carbohydrates.

Not the Average ‘Sweat’-er? If you believe that you sweat more, or less, than the average person, you can use a few other methods for determining adequate hydration.

• Weigh yourself before and after exercise. Fluid loss is usually the cause of any post-exercise weight loss, drink more to compensate. Any weight gain could also mean you’re drinking more than you need to, in this case try a little less water during your future runs.
• Monitor your urine color and amount. A large volume of light colored, diluted urine means you’re properly hydrated. Dark colored, concentrated urine is a sign of dehydration.

Something to Keep in Mind
If you are exercising at a high altitude or in extremely warm temperatures, you will most likely lose more fluid than usual. Compensate on these days with an extra glass during or after exercise.