Beetroot Juice and Exercise Performance: The Research

The case for beetroot juice as a sports drink sounds suspect the first time you hear it. Beets are not exotic. They are not new. And yet the last 20 years of exercise-physiology research have built a stronger evidence base for nitrate-rich beetroot juice than for almost any other legal supplement on the market.

The reason isn't the beet itself. It's the nitrate inside. Dietary nitrate enters a metabolic pathway that ends in nitric oxide, the same signaling molecule pharmaceutical companies have been targeting for decades to treat angina, hypertension, and erectile dysfunction. Boost nitric oxide naturally, and you change how efficiently your muscles use oxygen. That's exactly what beetroot juice does.

This article walks through the studies that built the evidence base, how big the effect actually is, who responds and who doesn't, and how to use it without wasting your money or your time.

The Research: What Studies Show

Larsen 2007: The First Signal

The modern beetroot juice story started with a small Swedish study. Larsen, Weitzberg, Lundberg, and Ekblom (2007), publishing in Acta Physiologica, gave nine well-trained men 0.1 mmol per kg of sodium nitrate (the same nitrate found in beets, just isolated as a salt) for three days, then had them ride a cycle ergometer. Submaximal oxygen consumption dropped from 2.98 to 2.82 L/min on the nitrate trial compared with placebo. A roughly 5% reduction in the oxygen cost of the same workload.

That finding rewrote a textbook assumption. Exercise scientists had long believed that the oxygen cost of a given workload was essentially fixed by mechanical efficiency. You could not get more work out of less oxygen. Larsen's data said otherwise.

Bailey 2009: Beetroot Juice, Not Just the Salt

Two years later, Bailey, Winyard, Vanhatalo and colleagues at the University of Exeter (2009) replicated and extended the finding using whole-food beetroot juice instead of isolated nitrate salt. Eight men drank 500 ml per day of beetroot juice (containing about 5.6 mmol of nitrate) for six days. Compared to a nitrate-depleted placebo beet juice, the supplemented condition showed a 19% reduction in oxygen demand during moderate-intensity cycling and a 16% extension in time to exhaustion at high intensity.

Bailey's paper is the one most often cited as the launching point for the beetroot-as-ergogenic-aid literature. It also opened a question that has not been fully answered: why did beet juice produce a bigger drop in oxygen cost (19%) than isolated nitrate salt (5%)? One hypothesis is that other beet compounds (polyphenols, betalains, vitamin C) augment the nitrate-to-nitrite-to-nitric-oxide conversion. The mechanistic case is still under active study.

Wylie 2013: How Much Is Enough?

By 2013, the question was no longer whether nitrate worked. It was how much you needed. Wylie, Kelly, Bailey and colleagues (2013) ran a dose-response study with 10 healthy subjects, comparing 4.2, 8.4, and 16.8 mmol of nitrate from beetroot juice concentrate (70, 140, and 280 ml).

At 8.4 mmol, the steady-state oxygen cost of moderate-intensity cycling fell about 1.7% (a trend, P = 0.06) and exercise tolerance during severe-intensity cycling improved significantly versus placebo. Doubling to 16.8 mmol pushed the oxygen cost reduction further (about 3%, P < 0.05) but produced no additional gain in exercise tolerance. The headline conclusion: the performance ceiling was already hit at roughly 8 mmol. That's the data underlying the modern dosing recommendation: aim for roughly 6 to 8 mmol of nitrate, and don't bother chasing higher doses.

In practical terms, 8 mmol of nitrate is roughly what you get in a standard 500 ml bottle of beet juice, or two 70 ml shots of concentrated beetroot juice ("beet shots") sold for athletic use. That's the operational target.

Domínguez 2017 and Senefeld 2020: Pooling the Evidence

By the late 2010s, the literature was big enough to pool. Domínguez and colleagues (2017) published a systematic review in Nutrients covering 23 studies on beetroot juice and cardiorespiratory endurance in athletes. They concluded that beetroot juice supplementation improves performance in events lasting from a few minutes to roughly 40 minutes, with the most consistent effect on time-to-exhaustion tests and on submaximal economy.

Three years later, Senefeld, Wiggins, Regimbal and colleagues (2020), publishing in Medicine and Science in Sports and Exercise, ran a more rigorous systematic review and meta-analysis. Pooling 80 placebo-controlled, randomized, crossover studies, they found a small but statistically significant ergogenic effect of nitrate supplementation on exercise performance overall. The effect was clearest in moderately trained recreational athletes; in highly trained elite endurance athletes, the pooled effect was smaller and not always significant.

Why elite athletes respond less is still an open question. The leading hypothesis: elite endurance athletes already have highly optimized oxygen economy and elevated baseline nitric oxide signaling. There's less headroom for nitrate to add anything.

How Beetroot Juice Actually Works

The mechanism is a three-step pathway. First, dietary nitrate (chemical formula NO₃⁻) gets concentrated in your saliva by the salivary glands. Second, bacteria living on the back of your tongue reduce nitrate to nitrite (NO₂⁻). Third, in the acidic stomach and in circulating blood and tissue, nitrite is reduced to nitric oxide (NO).

Nitric oxide is one of the most important signaling molecules in human physiology. In exercise specifically, it does three things that matter. It dilates blood vessels, improving oxygen delivery to working muscle. It improves mitochondrial efficiency, so each unit of oxygen produces more ATP. And it appears to reduce the ATP cost of muscle contraction, lowering the energy demand of generating a given force.

The combination is why nitrate is unusual among supplements. Most ergogenic aids work by recruiting more effort (caffeine, for example, reduces perceived effort). Nitrate works by reducing the underlying biological cost of the same effort. That's a different mechanism with different implications.

Why This Matters for Your Fitness

For a recreational exerciser, the practical question is whether a 3 to 5% drop in oxygen cost will change anything you can feel. The honest answer depends on what you're doing.

If you're running a 5K and trying to break a time, a 3% improvement in economy can shave roughly 30 to 60 seconds off a 25-minute race. That's noticeable. If you're cycling a hilly route, the extra time you can hold a hard pace before fatigue translates to meaningful real-world performance.

If you're doing easy zone-2 cardio for general fitness, beet juice will not feel like much. You'll move at the same perceived effort, and the lower oxygen cost will not register as a workout you "did better." The biggest effects show up at moderate to hard intensity, where the system is being pushed close to its limits.

This is also why the supplement category is so honest about its ceiling. Nitrate is not a stimulant. It is not motivational. It will not get you out the door on a day you don't feel like training. The whole reason it works is that it changes physiology, not psychology. As research on willpower shows, the workout you actually do beats the optimized workout you skip. Beetroot juice cannot fix the consistency problem. It just makes the workouts you complete slightly more efficient.

How to Use Beetroot Juice in Practice

Translating the evidence into a workable strategy:

• Target 6 to 8 mmol of dietary nitrate. That's roughly 500 ml of standard beetroot juice or one to two concentrated beet shots (70 ml each). Past 8 mmol, the Wylie data shows no extra performance benefit.
• Time it 2 to 3 hours before exercise. Plasma nitrite peaks roughly 2 to 3 hours after a single dose. That window matters more than people assume. A dose 30 minutes before training catches you on the rising slope, not the peak.
• Try chronic loading for harder sessions. A daily dose for 5 to 7 days produces a slightly larger and more consistent effect than a single acute dose. This is the protocol Bailey used (six days of 500 ml per day). For competitions or races, many coaches load for several days, then take a final dose roughly 2.5 hours pre-event.
• Do not use antibacterial mouthwash on dose days. Killing the oral bacteria kills the pathway. Multiple studies have shown that pre-dose mouthwash rinsing largely eliminates the rise in plasma nitrite and the corresponding performance and blood-pressure effects.
• Pick a form you'll actually use. Whole beet juice (500 ml bottles), concentrated beet shots (sold as athletic supplements), or just eating beets and other nitrate-rich vegetables (spinach, arugula, celery) all work. The shots are more expensive per dose but more convenient. Cooking destroys some of the nitrate, so raw or lightly steamed beets give the highest yield.

Individual Variation: Who Responds Most

Training Status

The clearest moderator of response is fitness level. Recreationally trained and moderately trained athletes consistently show the largest performance benefit. Elite endurance athletes (national-team-level cyclists, runners, rowers) show smaller and less reliable responses. The 2020 Senefeld meta-analysis flagged this difference explicitly: nitrate is most useful for people whose oxygen economy still has room to improve, which is most of us.

Exercise Modality and Duration

Beetroot juice shows the most consistent effect in high-intensity exercise lasting roughly 5 to 30 minutes (5K to 10K running, 4 km to 16 km cycling time trials, rowing). Effects in very short sprints (under 60 seconds) are smaller and less consistent, and effects in events longer than an hour are mixed. The middle range is the sweet spot, which is also where most recreational athletes train.

Diet and Oral Microbiome

People whose habitual diets are already high in leafy greens (spinach, arugula, lettuce, celery, beets) tend to show smaller responses to acute beet juice, presumably because their baseline nitric oxide signaling is already elevated. And anyone whose oral microbiome is suppressed (by mouthwash, by recent antibiotics, by some tongue-cleaning routines) loses the pathway entirely until the bacteria recolonize.

Common Misconceptions

Misconception 1: "Beetroot juice is a stimulant like pre-workout."

It is not. Beet juice produces no measurable increase in heart rate, blood pressure, or perceived energy in the way caffeine or stimulant pre-workouts do. The mechanism is the opposite. It typically lowers resting blood pressure (by 4 to 10 mmHg systolic in normotensive adults) and lowers the oxygen cost of submaximal exercise. You will not feel anything from a beet shot the way you feel a 200 mg caffeine dose. The benefit is invisible until you measure performance.

Misconception 2: "Eating salads and vegetables is the same as beet juice."

It can be, but the dose math is harder to hit. Eight mmol of nitrate is roughly 500 mg of nitrate. Spinach is the most nitrate-dense common vegetable at about 250 mg per 100 g, which means a 200 g spinach salad gets you to the target. Beets and beet juice concentrate are denser and more practical for pre-workout timing. A typical mixed salad delivers less than half the dose. So food works in principle, but volume becomes a problem if you're trying to consistently hit a performance dose.

Misconception 3: "If 8 mmol is good, 16 mmol is better."

The Wylie 2013 dose-response trial is unambiguous on this point. Doubling the dose from 8.4 to 16.8 mmol added no further benefit on plasma nitrite, oxygen cost, or performance. The biological response saturates near 8 mmol. Drinking more beet juice past that point gives you more sugar, more cost, and more pink urine, with zero additional ergogenic return.

What the Research Suggests Going Forward

The beetroot juice and exercise literature is mature on the basics. The dose-response is well-characterized. The mechanism is reasonably understood. The trained-vs-recreational distinction is well-documented. What's still being actively studied:

• Whether nitrate provides meaningful benefit in resistance training. The strength and power literature is mixed and the effect sizes are smaller than in endurance work.
• Whether chronic loading for weeks (rather than 5 to 7 days) changes mitochondrial adaptations in ways that compound. Most studies are too short to tell.
• Whether older adults (60+) respond more strongly than younger adults, since baseline nitric oxide signaling declines with age. Early studies suggest yes, but the data are thinner.
• Whether dietary nitrate combined with other ergogenic aids (caffeine, creatine, beta-alanine) stacks additively or whether the pathways interfere.

The takeaway for someone training today: beetroot juice is one of the few sports nutrition interventions where the research is strong enough to make a confident recommendation. It works. The effect is real but modest. The biggest gains go to recreational athletes pushing themselves at moderate to high intensity in events lasting 5 to 30 minutes. If that's you, hit the dose right and the timing right, and skip the mouthwash. If you're doing easy walks or recreational gym sessions, a daily beet juice habit is not going to change anything you can feel.

And none of this matters if you don't show up. A 3% economy bump on a workout you skipped is still zero. The biggest predictor of fitness outcomes is whether you keep stringing workouts together week after week. Pair the supplement with a real program if you want it to mean something.

References

1. Domínguez R, Cuenca E, Maté-Muñoz JL, et al. "Effects of Beetroot Juice Supplementation on Cardiorespiratory Endurance in Athletes. A Systematic Review." Nutrients. 2017;9(1):43. doi:10.3390/nu9010043
2. Bailey SJ, Winyard P, Vanhatalo A, et al. "Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans." J Appl Physiol. 2009;107(4):1144-1155. doi:10.1152/japplphysiol.00722.2009
3. Larsen FJ, Weitzberg E, Lundberg JO, Ekblom B. "Effects of dietary nitrate on oxygen cost during exercise." Acta Physiol. 2007;191(1):59-66. doi:10.1111/j.1748-1716.2007.01713.x
4. Wylie LJ, Kelly J, Bailey SJ, et al. "Beetroot juice and exercise: pharmacodynamic and dose-response relationships." J Appl Physiol. 2013;115(3):325-336. doi:10.1152/japplphysiol.00372.2013
5. Senefeld JW, Wiggins CC, Regimbal RJ, Dominelli PB, Baker SE, Joyner MJ. "Ergogenic Effect of Nitrate Supplementation: A Systematic Review and Meta-analysis." Med Sci Sports Exerc. 2020;52(10):2250-2261. doi:10.1249/MSS.0000000000002363