Australasian Science: Australia's authority on science since 1938

How Much Fluid Do You Really Need After Exercise?

fluid

Individuals are often advised to consume 1.5 times the amount of fluid lost during exercise and the recovery period.

By Ben Desbrow

The science behind rehydration following strenuous exercise is often lost in market hype.

The full text of this article can be purchased from Informit.

You find yourself exercising in a very warm environment for 1–2 hours. You’re hot, your sweat has soaked your clothes and your mouth is as dry as a chip, but you have no access to a drink.

You're told you can stop. You can drink but you can’t eat! You are given one drink in a volume you can only just tolerate – 800 mL every 15 minutes. You’ve been told roughly that you’re drinking “a new type of sports drink” but you’re not sure exactly what it contains. Regardless, you guzzle it down because you know that for the next 4 hours you will again be deprived of food and fluid.

At the end of the 4 hour rest period you’re again required to exercise. This time it’s a maximal effort for 45 minutes. After what seems like an eternity, the pain finally ends. You’re exhausted, hungry and it’s 2 pm.

The first of your four trials has ended, you are able to eat solid food again and you are welcomed to the unique world of rehydration science by one of the people who’s been looking after you for the past 7 hours. “See you back here same time next week!” says the researcher.

Does this sound like torture? Does this seem a little impractical? When does this occur in real life?

This example describes the most commonly used study design to assess the rehydration potential of beverages. While not all studies of fluid recovery after exercise employ...

The full text of this article can be purchased from Informit.