Mom always told you to eat your beets. As usual, her instruction was on point. The health benefits of beets are well documented, but there’s a new trend on the performance-enhancing block in the form of juice— and not the illegal kind. Beetroot juice can support athletic performance due to its high natural nitrate concentration that can improve cardiorespiratory endurance in athletes.
How does beetroot juice impact performance?
Knocking back a shot of beetroot juice can enhance muscle efficiency by reducing the oxygen-cost of exercise, lowering blood pressure and improving cognitive function. But what’s the hard science behind those claims? In a nutshell, beetroot gets its power from inorganic nitrates—the same kind found in dark, leafy green veggies.
After ingestion, nitrate is converted into nitrite by bacteria in our saliva. In the stomach, some of that nitrite converts to nitric oxide (NO), and the rest is circulated and stored as nitrite in our blood. Nitrites can be converted into NO during low oxygen availability, which mostly occurs in skeletal muscle during exercise.2
NO is something your body needs: it regulates blood flow, neurotransmission, immunity, muscle contraction, mitochondrial respiration as well as the balance of glucose and calcium.1 All the good stuff.
NO relaxes the muscles by widening blood vessels when it spreads through underlying muscle cells in the arterial walls. This affects how efficiently cells use oxygen -- efficient oxygen use is a very good thing -- and this is one of the reasons why beetroot juice can be used to support sport performance.
The benefits don’t stop there, though. Beetroot juice also contains other excellent nutrients that are great on their own and also act in conjunction with nitrates in beets3, such as:
- Antioxidants
- Polyphenols
- Resveratrol
- Quercetin
Fun fact: one study confirmed that it’s actually the nitrates, and not the other nutrients, that are responsible for most of the positive physiological effects of beetroot juice.
How do beets impact cognitive function of athletes?
Of course, your muscles aren’t the only critical component of sport performance. Your brain is pretty important, too. Think back to the last time you were exhausted and tried to run a 5k or complete an obstacle course. Chances are, your reflexes—and thus, your results—weren’t exactly sharp.
Beetroot juice benefits the brain, as well. One study investigated whether beetroot juice would increase blood flow to the brain and enhance brain function. 16 male team sport players completed a test twice: drinking a nitrate-rich beetroot juice before the first test, and a placebo juice before their second test. Beetroot juice was consumed for 7 days, with a bike sprint test administered at the end during which subjects simultaneously completed cognitive tests to evaluate accuracy and quickness of decision-making.
Despite no difference in response accuracy, the beetroot juice improved both sprint performance and speed of making decisions. The study concluded that the dietary nitrate found in beetroot juice can enhance repeated sprint performance and may reduce the decline in cognitive function, which influences reaction time.
Sounds like a pretty compelling reason to have a glass. If juice isn’t your thing and you’d prefer to just chow down on beets as a crunchy snack, it turns out that’s effective too. This study of a group of runners suggests that eating whole beetroot may be as effective in improving running performance as juice.
Beets and nitrates may benefit fast-twitch muscle fibers the most
Not all exercise is created equal, and different activities require different fuel. The same holds true in the case of beetroot juice—its efficacy varies according to a person’s fitness level and the intensity of the exercise.3 Andrew Jones, PhD, a physiologist and “beetroot expert” at the University of Exeter, points out that the effect of beetroot juice on prolonged endurance exercise hasn’t been explored much.
Fast-twitch muscle fibers — used in burst movements and which fatigue more quickly — may be more affected by nitrates than the slow-twitch muscle fibers used in sustained endurance exercise. As for fitness level, it turns out that highly-trained people could have higher blood nitrite values than those who are less trained, which means they might see less of a response to a typical dose of beetroot juice.4
How to use beetroot juice to enhance performance
How much beetroot juice should you drink?
Consuming more beetroot juice does have an effect on blood nitrite levels, but there is less of a return for enhancing performance.1 The optimal amount is 8.4 mmol of nitrate, but 5-9 mmol of nitrate/day is recommended as sufficient enough.3
When's the best time to drink beetroot juice?
According to Jones, beetroot juice could yield great effects if taken short-term before competition, from 2-6 days (and up to 15 days). But for acute effects, it should be consumed 2-3 hours before competition.
Where can you buy beetroot juice?
Beetroot juice supplements and their derivatives are popping up all over the place, and we’re not in the business of endorsing any particular brand, nor evaluating each. That’s why we’ve provided you with our handy, downloadable Beetroot Juice Recipe card, earlier in this post.
If you don’t own a juicer or are always on the go, you might want to check out one of the many pre-packaged beetroot products on the market.
What to know before adding beets in your diet
- Beetroot juice can turn your urine and stools red (especially in people with iron deficiency) because it contains dark carotenes called betacyanins that aren’t absorbed.5 Fear not — it’s nothing to worry about!
- People with kidney problems should avoid beetroot juice. Beets contain oxalates that can concentrate in body fluids and then crystallize in kidneys.
- Beetroot juice may cause some people to experience an upset stomach, diarrhea or nausea. This is because of a substance called betaine.6 It’s one of the reasons why beetroot juice manufacturers make concentrated juice "shots".
- Ultimately, experts say nitrate supplementation from vegetables like beetroot juice is unlikely to be harmful3, so drink up!
Want even more hacks? Download this guide of 9 ways to enhance endurance training now!
References
[1] Wylie LJ, Kelly J, Bailey SJ, Blackwell JR, Skiba PF, Winyard PG, et al. Beetroot juice and exercise: pharmacodynamic and dose-response relationships. J Appl Physiol. 2013;115(3):325–36.
[2] Richardson RS, Noyszewski EA, Kendrick KF, Leigh JS, Wagner PD. Myoglobin O2 desaturation during exercise. Evidence of limited O2 transport. J Clin Invest. 1995;96(4):1916–1926.
[3] Jones A. Dietary nitrate supplementation and exercise performance. Sports Med. 2014;44(Suppl 1):S35–S45.
[4] Poveda JJ, Riestra A, Salas E, et al. Contribution of nitric oxide to exercise-induced changes in healthy volunteers: effects of acute exercise and long-term physical training. Eur J Clin Invest. 1997;27:967–71.
[5] Watts AR, Lennard MS, Mason SL, Tucker GT, Woods HF. Beeturia and the biological fate of beetroot pigments. Pharmacogenetics. 1993;3:302-11.
[6]Bloomer, R. J., Farney, T. M., Trepanowski, J. F., McCarthy, C. G., & Canale, R. E. (2011). Effect of betaine supplementation on plasma nitrate/nitrite in exercise-trained men. Journal of the International Society of Sports Nutrition, 8, 5. https://doi.org/10.1186/1550-2783-8-5
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