By Matt Fitzgerald, Published Jun. 17, 2014 (running.competitor.com)
There’s been a lot of hype around beetroot juice lately. That’s because a few recent studies have shown that daily consumption of beetroot juice reduces the oxygen cost of exercise and increases high-intensity exercise tolerance.
But what is it in beetroot juice that produces these effects? Researchers have hypothesized that it’s dietary nitrates. Beetroot juice is known to contain high concentrations of nitrates, which in turn are known to enhance vasodilatation, or the capacity of blood vessels to dilate and increase blood flow.
A few years ago, researchers from Exeter University in the United Kingdom recently performed a study to test this hypothesis. They recruited nine subjects and gave them either regular beetroot juice or nitrate-depleted beetroot juice to drink every day for six days. Before and after this intervention all of the subjects underwent various exercise tests. After a washout period, the protocol was repeated with the two drinks switched.
The researchers found that consuming regular beetroot juice increased blood nitrate levels and reduced resting blood pressure. More importantly, it reduced oxygen consumption during moderate- and high-intensity running and increased time to exhaustion at high intensity by 15 percent.
That last result is most compelling because it is a performance metric. Who cares if a supplement reduces the oxygen cost of running if that physiological effect does not translate to improved performance? But in this case, it did.
On average, the subjects were able to run for 7.6 minutes at high intensity after six days of drinking nitrate-depleted beetroot juice. But after six days on regular beetroot juice they lasted 8.7 minutes.
I don’t know about you, but these results make me kind of thirsty. Thirsty for you know what!
About The Author:
Matt Fitzgerald is the author of numerous books, including Racing Weight: How To Get Lean For Peak Performance (VeloPress, 2012). He is also a Training Intelligence Specialist for PEAR Sports.