A Runners Hydration Guide: What You Need to Know

Maintaining hydration as a runner is important for health and performance. Learn why it’s important, and tips to stay hydrated before, during and after a run.

Why is water important? 

Water is necessary for every cell, tissue, and organ in your body to work normally. You need water to survive. Water is involved in four essential processes in your body:

  • It helps you easily flush waste and prevents kidney damage (including kidney stones) through sweating, urination, and bowel movements
  • It keeps your joints, skin, eyes, mouth and nose lubricated
  • It normalizes your temperature and reduces heat stress
  • It stops you from becoming dehydrated, which zaps your energy and reduces overall organ function

Adequate hydration can improve recovery, minimize injury and cramping and maximize performance. When we run, we generate 20 times more heat than when we are at rest. Our bodies cool down by sweating. However, sweating also leads to a loss of water and electrolytes, including sodium and potassium. When we are dehydrated, we may be tired, get headaches, cramp, and have an increased heart rate. Performance can suffer.

Tips to stay hydrated

Measure your sweat rate

Take your weight before and after a run lasting an hour or more. Replace each pound of body weight lost with 20 to 24 ounces of water. Do this along with eating foods containing carbohydrates and electrolytes, like a peanut butter and jelly sandwich. The carbohydrates will be used to refuel your muscles and the electrolytes for your body’s daily functions.

Many factors regulate your sweat rate. These include air temperature, run intensity, body size, gender, duration of the run, and fitness level. For instance, well-trained runners sweat more than runners that are less fit, because their bodies are more efficient at cooling themselves.

Drink regularly

Drinking water throughout the day is the best way to replenish fluid losses, as opposed to drinking all at one time.

  • Sip from a water bottle during the day.
  • Eat fruit. Fruit is a great source of water, as well as electrolytes and fiber
  • Thirst is not the best indicator of hydration status. Instead, make sure your urine is clear to light yellow. If it is dark, drink up
  • Rehydrate before drinking alcohol. Alcohol can be dehydrating and lead to inadequate storage of carbohydrates in your muscles, leading to poor performance and increased risk for injury

Drink water before, during, and after a run

Drinking before, during, and after training is just as important as drinking during the rest of the day.

  • Aim for 16 ounces (2 cups) of water about two hours before you run. Pair this with a snack or meal
  • About 15 minutes before a run, drink six to eight ounces of water
  • During a run longer than 1 hour, drink water at regular intervals. This varies according to your sweat rate. Those who sweat more profusely may need 16 ounces every 15 minutes. You’ll also want to consume some carbohydrates and electrolytes along with drinking water. Examples include sports gels and dried fruit.
  • After a run, aim for at least 16 ounces of water with food. Or, if you know your sweat rate, replenish with 20 to 24 ounces per pound lost.

Hydration during running is important for performance and health. Drink water regularly during the day and practice hydrating while on long runs. And don’t forget your need for carbohydrates and electrolytes to optimize your hydration and nutrition. All runners are different – find what works for you! 

We hope you keep these healthy tips in mind – especially those currently preparing for the Mercy Health Glass City Marathon. If you’ve been training but have yet to sign up, there is still time to register.

Mercy Health’s orthopedic and sports medicine team of physicians and running medicine specialists are here to help! They are available to assist you during your training and proudly provide medical aid to runners on-site during marathon race weekend.

Learn more about the orthopedic and sports medicine services we offer.