Energy drinks are known to boost athletes' performances. Now, a new study has shown that the drinks' benefits are felt even if the drink is spat out rather than swallowed.
The research team led by Ed Chambers has shown that whether it's real sugar or a tasteless carbohydrate, energy drinks can significantly boost performance in an endurance event, even if the drink isn't ingested.
During the study, Chambers and his colleagues prepared drinks that contained either glucose (a sugar), maltodextrin (a tasteless carbohydrate) or neither.
The athletes were asked to complete a challenging time-trial during which they rinsed their mouths with one of the three concoctions.
The researchers found that athletes given the glucose or maltodextrin drinks outperformed those on 'disguised' water by 2-3 pct and sustained a higher average power output and pulse rate.
The authors revealed that there are certain receptors in the mouth independent from the usual 'sweet' taste buds must be responsible.
"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," said Chambers.
With the help of neuro-imaging technique known as fMR, the researchers monitored the brain activity of the athletes and found that both glucose and maltodextrin triggered specific areas of the brain associated with reward or pleasure, while the artificial sweetener did not.
This acts to reduce the athletes' perception of their workload, suggest the authors, and hence enables them to sustain a higher average output.
The study appears in The Journal of Physiology.