A large part of what I focus on in this column is how you can alter your training to enhance performance. Training-schmraining…wouldn’t it be nice if there were ways to enhance performance without putting in any extra effort? Unfortunately, most effortless strategies that make as faster are dangerous and against the rules (EPO, blood doping etc.). There are a few, however, that are allowed and 100% work. One is the use of caffeine as I have written about here. Another ergogenic aid that is coming to the forefront of the literature is beetroot juice. With the more I read, the more it seems that under the right circumstances it actually works.
The Science
For a great review on the topic, check out this article. The active ingredient in beetroot juice is nitrate. Nitrate can be changed to the vasodilation-inducing molecule, nitrous oxide. Vasodilation (opening of the blood vessels) helps because it enhances oxygen delivery to our muscles as we push them to run at their limit.
Another proposed mechanism that I have seen in a few studies is related to enhanced oxidative phosphorylation and slowing of the rate of phosphocreatine breaking down. Without getting too complicated- you may remember from high school science that ATP is our cells’ energy source. Phosphocreatine is a great thing to have more of when we’re running because it is able to donate a phosphorus molecule to ADP to make more ATP for us. This process is quick and it happens anaerobically (does not require oxygen). It’s basically free energy, and it is very useful for short bursts of speed. Hence if beetroot juice results in less phosphocreatine breakdown, that will make for more ATP that is readily available to make us run fast!
How well does it work?
Depending on a number of different factors, the effectiveness of beetroot juice seems to differ.
Study #1: 5K Running Time Trial
Subjects were put through two 5K TT tests in a double blinded, randomized fashion. In one trial, 200g of baked beetroot was consumed, and in the other trial a placebo made from cranberry relish was consumed before the run. The study showed that the 5K TT times were faster post-beetroot consumption (Beet root speed: 12.7±2.7K/h Placebo: 11.9±2.6 k/h).
Study #2: 10K Cycling Time Trial
This study was a little different in that it looked at a beetroot juice loading protocol over 6 days. In any case, with a slightly different protocol, there once again seems to be something to the use of beets as an ergogenic aid. The 10K TT was about 1.2% faster with the beetroot juice loaded athletes. These athletes also pushed about 2% more wattage.
Study #3: 50M Cycling Time Trial
With the proposed physiological mechanism of how beetroot juice can help (i.e. the vasodilation and phosphocreatine retention), I have always been suspicious about the efficacy of this proposed performance enhancer as the duration of the event increases. Phosphocreatine is only useful for short anaerobic bursts, and I was/am skeptical of if the nitrates and subsequent nitric oxide produced from a one-time ingestion would result in any lasting vasodilation. That is why I found this study interesting.
8 highly trained cyclists completed a 50mile TT. Some consumed beetroot juice before the test, some did not. This is what they found: A reduction in 50mile TT time of 0.8% that was NOT statistically significant. In other words, there was no difference. Nothing is more misleading than when researchers say there was a difference (especially the one it seems they wanted to see) that was not statistically significant. Why run the stats if you won’t listen to them?
So in this study, for the 50-mile TT, there was no difference despite the researchers partially indicating otherwise. However, with a sample size of only 8, perhaps a statistically significant change would have been seen with more subjects. The length of the TT may have played a roll as well in some of the diminished beet juice gains. The authors also suggest that being a highly trained athlete may also explain why the beet juice didn’t work as well as in previous studies.
Study #4: Elite Cyclists, Shorter TT
To explore the influence of being highly trained and the effectiveness of beetroot juice, here is a good study that takes away the variable of a longer TT seen in the above 50M TT study. In this study, a clear increase in nitrate/nitrite was seen elevated in the blood in the beetroot juice athletes. There was only small increase in average power in the beetroot juice trial (290 vs. 285 W or 1.7%). They conclude that being a highly trained athlete results in a decreased efficacy of beetroot juice.
The authors of this study (even if you read the abstract) seem to downplay these gains when the numbers don’t 100% support their narrative. Yes, 5W is small, but this marginal gain did result in a massive 17s improvement in their 18-19 minute TT. I really don’t understand why the authors downplay this 1.7% power improvement while, for example, the 10K TT study above labeled a 2% gain as significant and conclusive.
Should you drink beetroot juice?
Based on everything I’ve read, I think it is reasonable to take a swing at using beetroot juice as an ergogenic aid. However, I think it is also important to keep in mind that it is likely to be more of an educated self-experiment vs. a sure way to go faster. If you consume enough, at the right times, and have no negative reaction to it, there’s a chance you could see maybe a 1-4% gain. There’s also a good chance it will do nothing. There’s also a chance it could give you GI issues and slow you down.
In addition to all of these unknowns, the more highly trained you are, many experts believe the body will find other ways to achieve vasodilation and phosphocreatine retention, and thus beetroot juice won’t be as effective.
As with many cases, more research is needed on exactly what type of athletes will benefit from the use of beetroot juice, how they should take it, and what types of races they should use it for.
I think it is also important to keep in mind that a 1-4% gain is very easily achieved by altering your training. If you are only running 40-50K/week, simply adding more quality or quantity is the foolproof way to go. If you are running 100M weeks, it might be tough to get a 1-4% gain from adding more training, but it also looks like there is doubt about beetroot juice helping you anyway.
Dr. Sean Delanghe, BSc. (Hons), DC is a chiropractor, coach, and a regular contributor to the RunWaterloo blog.
