Athletes' sweet swill of success.

ATHLETES may only need to rinse out their mouth with a sports drink to improve performance.

Experts found that receptors in the mouth pick up the presence of sugar and send reward and pleasure signals to the brain.

Although sports drinks and sweets are known to improve performance, it seems the sugar does not need to be absorbed by the body's muscles to have an effect.

Simply rinsing the mouth with a drink and spitting it out helps boost performance.

The small study, published in The Journal of Physiology, was carried out using endurance cyclists from the University of Birmingham and Manchester Metropolitan University.

Both trials found those swilling the drinks took two per cent less time and displayed an increase in power.

Scans enabled the researchers to identify regions in the brain that were activated by the drinks.

The authors concluded: "The results suggest that the improvement in exercise performance may be due to the activation of brain regions believed to be involved in reward and motor control."

Birmingham University's Dr Edward Chambers, who led the study, said: "Much of the benefit from carbohydrate in sports drinks is provided by signalling directly from mouth to brain rather than providing energy for the working muscles."

He added the findings support a theory that it is the brain itself that can limit performance.