Australasian Science: Australia's authority on science since 1938

Athletes Can Taste Victory

Athlete with sports drink

The findings raise the possibility of a “sixth taste sense” that is able to detect energy density.

By Stephen Luntz

The taste of an energy-laden drink can produce a surge in muscle strength even before glucose hits the bloodstream.

In a study run by Dr Nicholas Gant and Dr Cathy Stinear of the University of Auckland’s Centre for Brain Research, 16 young men held weights for 11 minutes, flexing every 2 minutes. “Not surprisingly, the maximum force they could produce decreased over time,” Stinear says. However, when given an energy drink the participants showed 2% more muscle strength only 1 second later.

“It might not sound like much, but a 2% increase in muscle strength is enormous, especially at the elite level. It’s the difference between winning an Olympic medal or not,” says Stinear. Other participants who were given an identically flavoured placebo continued on the downward path.

Stinear has confidence the effect is real, saying: “Our data weren’t particularly noisy at that point”. Neural activity in the brain pathway that activates the biceps shot up by 30%.

The findings raise the possibility of what Gant calls a “sixth taste sense” that is able to detect energy density, although other recent research into a taste for fats (AS, May 2010, p.6) may push it to a seventh sense.

However, the mechanism and evolutionary reason for such a taste sense remain unclear. Prior to the invention of artificial sweeteners, the conscious taste for sweetness would seem sufficient to detect the presence of carbohydrate energy. Stinear is also keen to find out if non-carbohydrate energy can be detected in the same subconscious way.

Participants in the study experienced a further boost in muscle strength when the glucose actually hit the bloodstream, and Gant and Stienear have not been able to establish whether there is a subsequent price for the immediate increase in strength.

Stinear says she and Gant have just started “chipping away” at the host of questions raised. In one further experiment their team found a smaller effect for the muscle between the thumb and forefinger for subjects who were not tired. They have yet to determine whether the smaller magnitude of the effect is because of the different muscle, or if the strength boost is larger when the relevant muscle is tired.

Stinear warns advantage-seeking athletes: “We’ve only just got preliminary evidence the mechanism exists. It’s too early to say how it is functional.”