A new scientific study has found that carbohydrate drinks can make you cycle faster, even if you never swallow them.

A study undertaken at the University of Birmingham found that riders taking part in a time trial rode faster when they swilled their mouth out with a drink containing either glucose or maltodextrin and then spat it out.

Other cyclists in the same study who were given a placebo drink containing artificial sweeteners did not improve their time in the trial.

The researchers believe that the astonishing result is due to receptors in the mouth sending signals to the brain, which then makes hard exercise feel easier. The effect is that the cyclists felt more comfortable working their bodies harder – with a 2-3 per cent improvement in performance.

A subsequent brain scan of people who had tasted glucose showed that their brain responded by triggering a ‘pleasure’ response, reducing their perceived fatigue during exercise.

The study, “Carbohydrate sensing in the human mouth: effects on exercise performance and brain activity” by E. S. Chambers, M. W. Bridge and D. A. Jones of the University of Birmingham is published in the current issue of the Journal of Physiology.