Hydration: What Every Runner Needs to Know

Updated: Mar 8

Table of Contents:

How Much Water Should Runners Consume

Dehydration vs Hyponatremia

Importance of Hydration

19 Benefits of Drinking Water

What Happens When You Don't Drink Enough Water

How Much Water Should Runners Consume

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. So, it’s important to drink plenty of fluids while exercising to replace the fluids lost from sweating.

Here's a breakdown of hydration for athletes.

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.

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

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.

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.

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.

Dehydration vs Hyponatremia: What’s The Difference

A well-known fact about the body is that it is made up of 60% of water. Water plays a huge role in the function of the human body.

On a daily basis, it is recommended for males to consume roughly 3 liters and females 2 liters of water. If you exercise, an additional 3 to 4 liters may need to be consumed to replenish and hydrate your body. If your body is not properly hydrated it can lead to dehydration. In rare cases, you can flood your system with too much water and become hyponatremia.

What is Dehydration

When your organs are deprived of fluids and unable to properly function your body is dehydrated. The three most common causes of dehydration are sweating, vomiting, and diarrhea. Depending on how the scale dips, there are three types of dehydration.

Types of Dehydration

Isotonic Dehydration

Both water and sodium levels are low. Your body has lost an equal amount of water and electrolytes. Some symptoms include decreased blood pressure, dry skin, and a fast heart rate.

Hypertonic (Hypernatremia) Dehydration

The concentration of sodium is much higher than the volume of water in your body. Some symptoms include extreme thirst, dark urine, and dark skin.

Hypotonic Dehydration

The concentration of sodium is much lower than the volume of water in your body. Some symptoms include confusion, muscle twitches or cramps, and low blood pressure.

Signs and Symptoms of Dehydration

Seek medical attention if you experience any of the following signs and symptoms:

  • Confusion

  • Dizziness/Lightheadedness

  • Fatigue

  • Dark urine

  • Decrease in urination

  • Muscle Twitches/Cramps

  • Tachycardia (fast heart rate)

  • Low blood pressure (severe cases)

  • Bluish skin (severe cases)

  • Weak pulse (severe cases)

Treatment for Dehydration

Replenish your body with water and electrolytes.

What is Hyponatremia

When your body has an excess amount of water in relation to the concentration of sodium, your body experiences hyponatremia. The body needs electrolytes to regulate the amount of water in your body. When these levels become too low, your body becomes overwhelmed with too much water.

Types of Hyponatremia

Hyponatremia can be declared as chronic or acute.

Acute Hyponatremia

Acute hyponatremia is when the sodium levels drop rapidly. Some signs and symptoms include muscle cramps, nausea, weakness, and confusion.

Chronic Hyponatremia

Chronic hyponatremia is when the sodium levels drop gradually over 48 hours or longer. Some signs and symptoms include lethargy, restlessness, disorientation, headache, and nausea.

Signs and Symptoms of Hyponatremia

Seek medical attention if you experience any of the following signs and symptoms:

  • Nausea

  • Vomiting

  • Fatigue

  • Headache

  • Confusion

  • Loss of energy/Drowsiness/Fatigue

  • Restlessness and irritability

  • Muscle weakness/Spasms/Cramps

  • Seizures

  • Loss of consciousness/Coma