Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

about us





Whey shake restores fluid balance

Athletes who have lost large quantities of fluid can use a mix of carbohydrates and whey without problems, we wrote a few days ago. This kind of shake speeds up muscle recovery and restores fluid balance at the same time, British sports scientists discovered. The same researchers recently published a study in Amino Acids, in which a shake containing only whey had the same effect.

Whey shake restores fluid balance
Experimental setup
The researchers got 10 students to cycle on two different occasions at a temperature of 35 degrees until they had lost 1.7 percent of their bodyweight mostly through transpiration.

In the hour immediately after the session the students drank water on one occasion, and water in which the researchers had dissolved whey isolate on the other occasion. The composition of the whey drink is shown here below.

The subjects drank 1.5 times as much fluid as they had lost.

Whey shake restores fluid balance

Fluid balance
The students spent the first four hours after they had replenished the fluid they had lost in the lab so that the researchers could monitor the restoration of their fluid balance.

The watery shake containing whey restored the whole body net fluid balance just as well as water did, the researchers discovered.

Whey shake restores fluid balance

The shake contained 20 g whey per litre. The whey shakes that athletes drink in real life are often more concentrated. These might work less fast, the researchers suspect.

"In theory, as an energy-containing macronutrient, the addition of whey protein to a rehydration drink should delay the rate at which the drink empties from the stomach, thus slowing the delivery of water to the circulation", the researchers write. "It is, however, unlikely that the addition of 20 g/L whey protein isolate is a large enough increase in energy density to significantly alter the gastric emptying rate or fluid delivery."

Restoration of fluid levels and consuming whey for muscle recovery can be done simultaneously without problems, but you do need to use shakes that are considerably thinner than the ones you're probably used to.

Amino Acids. 2014 May;46(5):1217-24.

Rehydration and whey protein administration go together fine 28.07.2014
Full meal is best rehydration strategy 26.08.2009
Sports drink with sugar restores fluid balance for longer than water 19.08.2009