Researchers at the University of Exeter found that the brightly-coloured juice gives professional cyclists such a boost that they can shave vital seconds off their time.
Beetroot juice is a natural source of nitrate, which is thought to be the active ingredient in affecting athlete’s performance.
According to the scientists, the chemical, once inside the body, starts widening blood vessels, speeding oxygen flow to the muscles, including the brain, and allowing them make the most of the oxygen breathed in, the Daily Mail reported.
Previous studies have showed that the juice helps in lowering blood pressure, warding off dementia, and even giving energy to elderlies.
In the latest study, published in the journal Medicine and Science in Sports and Exercise, the Exeter team asked nine men who cycle competitively to compete in time trials over 2.5 miles and 10 miles.
Before setting off, they drank just a pint of beetroot juice. They repeated the two routes on a different day, but this time fuelled by beetroot juice missing its nitrite.
When the cyclists drank the nitrite-rich, ordinary beetroot juice they were 11 seconds quicker over the shorter distance and 45 seconds quicker over the longer route.
While this may not sound like much, the top two riders in last year`s Tour de France were separated by just 39 seconds.
"This is the first time we`ve studied the effects of beetroot juice, and the high nitrite levels found in it, on simulated competition," said study author Dr Andrew Jones.
"These findings show an improvement in performance that, at competition level, could make a real difference -- particularly in an event like the Tour de France where winning margins can be tight," Dr Jones added.
And it is not just professional athletes who could benefit, with better use of oxygen making it easier for the old and frail to complete everyday tasks, including providing the energy needed to walk to the shops, the scientists said.
The study used shop-bought beetroot juice but home-made versions should also be beneficial, they said.
However, there could be an unexpected result. A quirk of genetics means that eating beetroot leaves some people producing purple urine, or `beeturia` as it is known to scientists.