Posted by Brigham and Women's Hospital March 24, 2015
Maintaining hydration as a runner is important for health and performance. Water regulates our body temperature, removes waste, helps brings energy to our cells, and cushions our joints. Adequate hydration can improve recovery, minimize injury and cramping, and maximize performance.
When we run, we generate twenty times more heat than when we are at rest. We avoid cooking ourselves by sweating, which cools our bodies. However, sweating also leads to loss of water and electrolytes, including sodium and potassium. In fact, losing more than two to three percent of our body weight through fluid (3-5 pounds for a 150-pound person) can lead to dehydration. When we are dehydrated, we may be tired, get headaches, cramp, and have an increased heart rate. Performance can suffer.
Tip #1: 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 20-24 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 less fit runners, because their bodies are more efficient at cooling themselves.
Tip #2: 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 for 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.
Tip #3: 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 at 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 one 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 20-24 ounces per pound lost.
The Bottom Line
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, so meeting with a registered dietitian can be beneficial to understanding your individual needs.