In 2018, based on good evidence, the International Olympic Committee formally recognized beetroot as a legitimate sports food.
Much of the credit for beetroot’s superior reputation comes from the fact that it’s rich in nitrates which, when consumed in food, convert to nitric oxide – which causes blood vessels to relax and widen and lowers blood pressure.
But there is a mystery. Why does beetroot improve exercise performance while other foods rich in nitrates do not?
Part of the answer is that beetroot also contains good potassium levels (good for the heart by balancing sodium levels) and polyphenols, which are believed to reduce inflammation.
But there may also be an unknown substance that makes the nutrients of beetroot more available to the body.
The mystery of why some foods nourish the body better than others with a similar nutritional profile lies at the heart of a new study.
Noah D’Unienville is the paper’s Ph.D. candidate and principal investigator from the Allied Health & Human Performance program at the University of South Australia.
He says, “There is a lot of interest in nitrate-rich and polyphenol-rich foods for their potential to improve exercise performance, but just because they contain these elements doesn’t mean it will translate into improved exercise performance.”
The Legendary Gift
The legendary gift to athletes is that the nitrates in beetroot stimulate blood flow and increase the delivery of nutrients and oxygen to muscles during exercise.
As we previously reported, several studies over the past decade — including a 2015 experiment involving Australian kayakers — supported the legend that beetroot juice improved athletic performance.
In a 2011 study, professional cyclists who drank beetroot juice improved their pedaling performance by 2.8 percent. That’s a lot when considering that anything that gives an elite athlete the smallest advantage is a big problem.
But there is a limit.
However, the University of South Australia study suggests that the benefits of beetroot have a ceiling for elite athletes.
Noah D’Unienville told news gear that once athletes reach high V̇O2 max levels (meaning their maximum oxygen uptake and aerobic capacity), the aerobic benefits of beetroot are irrelevant.
As Dean of Programs (Human Performance) Professor Jon Buckley notes, “While these foods were effective at improving exercise performance and building endurance, their effects discriminated.
“The results did show that there were more significant effects in athletes who were less fit.”
It was also found that men were “more likely to benefit from these foods than women.”
Professor Buckley admitted there were “some limitations with the sample size of women”.
This is a problem that plagues sports research.
Professor Buckley said: “This finding suggests that further research is warranted”.
The study — a meta-analysis of 118 studies involving 1,872 participants from 25 different countries — “evaluated the effect of consuming nitrate-rich foods (usually green leafy vegetables), foods containing polyphenols (such as berries, cherries, and cocoa), and the amino acid L-Citrulline (found in watermelon) on exercise endurance”.
The study found that “the nitrate levels in beetroot, which have been shown to boost blood flow and increase the delivery of nutrients and oxygen to muscles during exercise, helped athletes perform better and faster.”
Likewise, the polyphenols in grape, cherry, and pine bark extract “helped protect nitrate from a breakdown in the body, increasing endurance.”
Although L-citrulline can boost nitric oxide production in the body, “consuming watermelon (rich in L-citrulline) did not improve exercise performance.”
Mr. D’Unienville told the news that gear beetroot produced the most significant results of all these foods.
See here for our report on how beetroot protects the brain from aging and promotes a healthy oral microbiome.