London - It seems a most unlikely performance booster, but beetroot could be the secret to track success at this year’s Olympics.

Scientists have discovered that athletes who eat baked beetroot before a race run faster.

The vegetable contains high levels of chemicals called nitrates, which have been shown to boost exercise performance.

Researchers at St Louis University in the US recruited 11 fit and healthy men and women and got them to twice run five kilometres on a treadmill.

Before the first run, the volunteers consumed a portion of baked beetroot just over an hour before hitting the treadmill. Their average speed was 12.3 kilometres per hour, around 7.6mph.

Before the second run, they ate an equivalent amount of cranberry relish, chosen because it has a similar calorific content to beetroot but lower nitrate levels. This time the runners averaged only 11.9 kilometres per hour, or 7.3mph.

The researchers, whose study is published in the Journal of the Academy of Nutrition and Dietetics, said runners appear to be able to maintain their speed for longer if they have eaten the vegetable.

“During the last 1.1 miles of the run, speed was five percent faster in the beetroot trial,” they said.

The study only looked at baked whole beetroot, but the findings could apply to beetroot cooked in other ways or to the raw vegetable.

Tests by the agriculture department in the UK in the 1990s found nitrate levels are highest in raw beetroot but that cooking it has no significant impact on them. - Daily Mail