Hydration Needs for Runners

As a runner, you may already know the impact dehydration can have on your performance. Here's a few simple guidelines to follow to help assure you're getting the proper hydration you need for optimal performance.

A 1% loss in body weight during your run (i.e. 1.5 lbs in 150 lb person) makes the heart beat 3-5x faster/minute. A 2% loss is defined as dehydration (i.e. 3 lbs in 150 lb person) and a 3% loss significantly impairs performance (i.e. 4.5 lbs in 150 lb person). Here's a chart to assure you’re meeting your personal hydration needs:

Aim for at least 4 oz. (approximately 4 "gulps") of fluid every 15-30 minutes. Majority of races have water stations every 2-3 miles, so take advantage of these and hydrate as needed! You don't need to "chug" the full cup at each station, you can carry it with you and sip if it's difficult for you to drink 4 oz. all at once while running. Try alternating between water and sports drinks at every other station...so if at mile 6 you grab water, make sure to grab a sports drink at mile 8 or 9. This way you'll be replenishing both fluids and electrolytes.  

Sweat Rate

Common sweat rate ranges from about 1-4 lbs per hour. This number can vary so much depending on the person, their body weight, temperature, etc. Due to this variation, I highly recommend calculating your own sweat rate. This can be done by weighing yourself immediately before a run, & immediately after – while also keeping track of how many ounces of water you drink. Knowing this info can help me calculate how much water you should be drinking every 15, 30, or 60 minutes. For each pound lost in sweat, 16 oz. (or 2 cups) should be consumed immediately after your run.  

Hyponatremia & Electrolyte Needs

There is such a thing as “too much of a good thing”! Drinking too much water can increase your risk of hyponatremia (i.e. low blood-sodium levels that can cause headaches, muscle spasms, or even seizures). Prevent this by drinking according to your personal needs or “sweat rate” and replacing sodium & other electrolytes lost through sweat via sports drinks or electrolyte packets. You could make your own sports drinks with my homemade recipes

In this chart, I've compared the nutrient content of my homemade sports drinks recipes (see watermelon recipe below) to Gatorade. The carbohydrate source in my drinks is natural sugar from fruit, potassium from coconut water (and orange juice), & sodium from sea salt.

Hotter temperatures call for increased hydration & electrolyte needs, such as potassium! Failing to replace potassium during and after workouts can lead to: muscular aches, cramps, fatigue, or even spasms, heart palpitations, constipation, or nausea. Adults should be taking in 4.7 grams of potassium per day. Some potassium rich foods include: baked potatoes, sweet potatoes, milk, yogurt, melon, bananas, avocado, spinach, broccoli, & coconut water. Read my blog on potassium here for more info on this electrolyte.

Eleat Watermelon Sports Drink

Watermelon is rich in L-citrulline, an amino acid that research has shown helps to reduce muscle soreness in athletes after intense workouts. This recipe combines the powerful antioxidants and nutrient content of watermelon, with electrolytes from coconut water and salt for a "natural" sports drink excellent pre, during, and post-workout. 


1 cup fresh watermelon (chopped)

1 cup coconut water

juice squeezed from half of a lime

pinch of sea salt (or approximately 1/16 tsp)

Combine all ingredients together in blender. Enjoy immediately after making. 




Training for a race? Contact me to set up an appointment to help you train and compete at your best. Will help guide you every step of the way by determining sweat rate, hydration & electrolyte needs, providing meal plans, and educating on proper carb-loading techniques.