Hydration for Endurance: Running

Fluids

It can be challenging to get enough fluids when you race. However, in order to ensure the best run you can, it is vital to drink enough fluids. 

Below are some common factors that influence sweat losses:

  • Duration and intensity
  • Environment condition
  • Type of clothing
  • Body weight
  • Genetic predisposition
  • Heat acclimatization state
  • Metabolic efficiency 

 How to Hydrate: Pre/During/Post Exercise

  1. Pre-exercise: Two hours before running you should consume between 14 to 22 ounces of fluid.
  2. During: Consume 6 to 12 oz every 15-20 minutes, depending on calculated sweat rate (explained below). You should consume an average of 1 gram of sodium per hour.
  3. Post-exercise: Drink 16 to 24 ounces for every pound lost during exercise. You should incorporate beverages and snacks that contain sodium.

Tips

  • If competing in a hot and humid environment, use extra sodium.
  • Consume higher sodium foods 1 or 2 days before long rides.
  • Drink fluids that contain sodium. (i.e. sports drinks) during and after exercise.

Calculating your Fluid Needs

Not everyone needs the same amount of fluids. One size does NOT fit all. Figure out your sweat rate so you can create a fluid plan that meets your needs. 

Guidelines for calculating your fluid needs:

Your weight before exercise minus your weight after exercise = pounds lost through insensible losses and sweat
Weighing before exercise:
  • No clothing
  • Do not drink any water after weighing. (Note: It is ok to drink water before you weigh)
  • Do not urinate after weighing
Then go and perform 1 hour of vigorous exercise. DO NOT drink any water or urinate while training for this hour.

Weighing after exercise:

  • No clothing
  • Do not drink any water before weighing
  • Do not urinate before weighing
For every pound lost you must consume 16 oz of fluid.  

For example: A person’s weight was 160 pounds before exercise and trains for one hour. After training the scale shows their weight to be 158 pounds. Since 2 pounds were lost and you must consume 16 oz for every pound, this person must consume 32 ounces of fluid per hour of riding.