Melbourne scientists showed pairing caffeine with food dramatically boosted the body's levels of glycogen, the main fuel source for muscles. The findings, published in the Journal of Applied Physiology, offered Australia's Olympic competitors a new way to power-up in preparation for the Beijing Olympic Games, lead researcher, RMIT University Professor John Hawley, said.

The research found athletes who added caffeine to their post-exercise meal had 66 per cent more glycogen in their muscles than those who ate only carbohydrates.

''If you have 66 per cent more fuel for the next day's training or competition, there's no question you'll be able to go further and faster,'' Professor Hawley, who heads the university's Exercise Metabolism Group, said.

While it has been established that carbohydrates and caffeine improve athletic performances, this is the first study to show the combination can be used afterwards to help muscles refuel more rapidly.

The research involved four assessment trials with seven endurance cyclists who were given either a plain carbohydrate drink or one containing the caffeine equivalent of six strong cups of coffee.

The cyclists rode a cycle ergometer until exhaustion. Four hours later those who had consumed the drink containing caffeine had 66 per cent higher glycogen levels in their muscles compared with those who had the carbohydrate-only drink.

Professor Hawley said the research could help elite sportspeople looking for an edge over their competitors. ''But because caffeine can potentially have negative effects such as disturbing sleep or causing the jitters athletes who want to incorporate it into their recovery routines should experiment and see what works for them well before any serious competitions,'' he said. AAP