One of the more interesting foods/supplements that has been gaining traction over the last few years is beetroot juice.
Oftentimes people, particularly endurance athletes, will spend a lot of time and money on things that do may or may not work in the hopes of a small increase in performance. At the top level, this small increase in performance can make a big difference in outcomes.
Most supplements do not live up to the hype, but it looks like beetroot juice could be an exception to that since it consistently seems to help people improve their performance.
That being said, there is a bit of nuance to the topic. It certainly is not a magical supplement guaranteed to help you dramatically improve your time.
How It Theoretically Works
The way beetroot juice works is through the effects of nitrates.
Nitrates are typically found in vegetables and they mainly act by vasodilation and improved blood flow.
To confirm that nitrates are the key factor in why performance is improved, one study removed Nitrates from beetroot juice and found that the benefits also disappeared, highlighting that nitrates are key.
While we have a clear outcome in terms of improved performance, the mechanism through which this improved performance comes is still debated.
The most common opinions people have been that beetroot juice reduces the energy cost for movement, which improves efficiency AND that there is enhanced muscle metabolic function, which also leads to less muscular fatigue during exercise.
Research on Beetroot Juice and Endurance Performance
There are quite a few studies on beetroot juice and the research is at the point that there are clear situations where we know it is beneficial.
Like most areas of sports performance though, there are still plenty of areas in regard to beetroot juice that require more study.
One notable study highlighted that runners who consumed a shot of beetroot juice pre-race cut 2.4% off their 5km time.
This may not sound massive, but most of the best sports supplements will provide a performance boost of up to 1-2% in terms of race time. So a boost like this is definitely worthwhile considering.
Although time-to-exhaustions (TTE) trials can have the major flaw that they are not exactly relevant to actual endurance sports like running, cycling or swimming, another study on cycling showed a 16% improvement in TTE.
And lastly, since single studies can paint a misleading picture, there is a meta-analysis of 23 beetroot juice studies highlighting that beetroot juice consistently improves performance in endurance events.
Potential Lack of Effect in Some Cases
The most common argument people seem to have against beetroot juice is that it might be less effective in elite athletes than it is in novice athletes.
From the optimistic perspective, at least that means if you are new to the endurance game, you are likely going to see great improvements from taking beetroot juice.
There are a few studies showing no benefit to beetroot juice, such as this one on well-trained cyclists doing a 50-mile time trial. In this case, the authors speculated that the better training status of the elite athletes might reduce the physiological and performance response of beetroot juice.
Along those lines, other people have speculated that top-level athletes have already maximised whatever physiological mechanisms that are improved via beetroot juice.
Other people have speculated that beetroot juice is still beneficial for elite athletes, but perhaps higher dosages are required. For example, in this study on well-trained cyclists consuming high dosages of beetroot juice, there was a benefit.
There are minimal side effects to beetroot juice supplementation.
A small percentage of people find that it can change the colour of their urine to a red or pink colour, but that is about it.
Outside of that, I can only really identify two downsides of it.
- It can taste pretty horrid to some people. It is not uncommon for people to have it pre-training and then leave them feeling a bit nauseous.
As with most supplements, since the performance improvement from the supplement is not massive, any clear detriments like nausea could potentially outweigh the benefits.
2. It can also be quite expensive.
In Australia, the most commonly recommended source of concentrated beetroot juice is Beet-It which appears to often be around $5 a shot even when purchased in bulk. So price is certainly a factor here for a lot of people.
If money is not an issue, then that second point is not really valid.
In terms of taste, I have seen somebody else say “If I could take a shot of tequila, I could handle a shot of beet juice” which is also a valid point. If it just tastes bad but does not impact your performance with nausea, I would wager most athletes striving for optimal results would be willing to make that sacrifice.
Dosage and Timing
The ideal dosage appears to be around 5-7mmol of nitrate for most people, taken around 3hrs before training. This equates to roughly 250-300g of nitrate-rich vegetables per day.
The effects typically take 30 minutes to be noticeable, peak after 90 minutes and last for 6-8hrs.
This equates to 500ml of regular beetroot juice or 70ml of Beet It, which is a more concentrated version.
It is also worth noting that taking beetroot juice daily for 3-4 days actually improves its effectiveness even more than acute dosage. Arguably it would make sense to do that instead of just a once-off dose. The effects seem to plateau after about 6 days though.
The final thing to be aware of is that you must not brush your teeth or use mouthwash right after taking beetroot juice. This can block the conversion of nitrates into nitrites, which also blocks the effectiveness of the supplement.
Other Food Sources of Nitrates
It is possible to consume this amount of nitrate for performance-enhancing benefits through food. The main challenge is that in some circumstances the total food volume could potentially be too much to be feasible or could take away from the opportunity to reach other dietary goals.
For context though, the below table provides some information of the nitrate content of vegetables.
The other point to add to this topic is that the nitrate content of foods, including beetroot, can be highly variable.
This issue is even present in the supplemental form of beetroot juice. Research has shown that even selecting multiple copies of the same brand and product can potentially have a large difference in their nitrate content.
Is It Worth Taking Beetroot Juice?
The way I would view it, is if you are in a position where a 1-2% improvement in your performance is worth the time, money, taste and all the other variables involved in this, I think it is worthwhile taking.
If it either negatively impacts your performance due to nausea (which is less likely to be an issue the further away from your training/competition you space it out) or the cost investment is not worth it, then I likely would not recommend it.
If you are an outlier who does not seem to benefit, the worst-case scenario is that you have just consumed an antioxidant and nutrient-rich drink that can have other benefits as well, so that is a positive as well.