Updated: Aug 27
Sweating is a natural mechanism to cool down the body and return to its optimal temperature during exercise. Although sweating is beneficial, it can also be harmful if the body is not hydrated. Hydration before, during, and after exercise can minimize injury and cramping, improve recovery and performance, regulate your body temperature, remove waste, provide energy to your cells, and cushion your joints. So, it’s important to drink plenty of fluids while exercising to replace the fluids lost from sweating.
How Much Water Should You Drink Before Running
On any given day, the recommended daily intake for water is 3.7 liters for men and 2.7 liters for women. For active individuals, your body requires more fluids to replenish the lost fluids from the exertion of sweat and breathing.
Starting a workout when your body is already in a dehydrated state can lead to you getting dizzy, lethargic, muscle cramps, and contribute to a poor workout. Drinking water is important, and your body will thank you for it.
For athletes, drink 17 oz - 20 oz of water two hours before exercising and 7 oz - 10 oz 15 minutes before starting your workout.
How Much Water to Drink While Running
In the article, “5 Water Requirements During Exercise in the Heat,” published by NCBI, a study was conducted on military personnel to determine water intake based on workload. The article observed different factors that may increase sweat rates and found sweat loss can range from 3 liters - 4 liters per hour to as much as 10 liters per day. Factors such as the intensity of training or exercise and heat acclimatization can increase sweat rate by 10% - 20% (200 ml - 300 ml per hour).
Other factors that can impact sweat rate are gender, age, humidity, temperature, wind, solar radiation, and fitness level, to name a few. All these variables can make it easy to underestimate or overestimate your sweat loss and fluid intake. Both can be dangerous leading to dehydration or hyponatremia.
Dehydration and hyponatremia are serious conditions. Seek medical attention if you think you are at risk.
If you are a novice or experienced runner, always listen to your body. Your body sends signals to the brain to let you know when it needs nutrition or hydration.
During exercise, the recommended amount is to drink 7 oz - 10 oz of water every 10 min - 20 min.
How Much Water to Drink After Running
After exercising, bodyweight loss is how fluid intake is measured. If you run for 60 minutes or more, check your weight before and after. This is a quick and easy way to determine how much water your body needs to replenish itself.
Another way to see how dehydrated your body is, is by the color of your urine. If your urine is a dark shade of yellow, your body is dehydrated. You'll want to continue to drink fluids until your urine has become a light shade of yellow.
The recommended amount is to drink 16 oz - 24 oz of fluid for every pound of body weight lost after exercise.
How to Stay Hydrated on Long Runs
For short-distance runs, you can drink water and not have to worry about your electrolytes. For long-distance runs, those lasting 75 min or more, you need to replenish your body with electrolytes.
Weather conditions can directly impact your water and electrolyte balance. In dry, hot conditions, your body sweats more to bring your body temperature down, meaning you need more liquids than if you run in wet, cooler conditions.
The amount of water and electrolytes you need to replenish your body will depend on many factors. Keep in mind, the harder and longer you work out, the more sweat your body gives off. The more you sweat, the more fluids and nutrition your body needs.
To hydrate your body, you will need to consume sugar or maltodextrin (slow-release carbohydrate) and electrolytes. For novice runners, carrying a water bottle or having a pack is always highly recommended, even if it is under 30 minutes. Even experienced runners should carry water with them.
On any given day, the recommended daily intake for water is 3.7 liters for men and 2.7 liters for women. For athletes, drink 17 oz - 20 oz of water two hours before exercising and 7 oz - 10 oz 15 minutes before starting your workout. During exercise, the recommended amount is to drink 7 oz - 10 oz of water every 10 min - 20 min. The recommended amount is to drink 16 oz - 24 oz of fluid for every pound of body weight lost after exercise. To hydrate your body, you will need to consume sugar or maltodextrin (slow-release carbohydrate) and electrolytes.