Beetroot Juice as a Natural Pre-Workout

Educational journalism, not medical advice. Every claim here is checked against its cited sources by editor Tim Bunce — a health writer, not a physician. It isn’t specific to your situation: for health decisions, talk to your own clinician. How we work →

Why beetroot is taken seriously

Most “natural pre-workout” claims are unsupported. Beetroot juice is the rare exception: there are now over 200 peer-reviewed performance trials on dietary nitrate, with consistent though modest effects. The mechanism makes biological sense, the doses are well-defined, and the side-effect profile is mild.

The effect is mediated by inorganic nitrate (NO₃⁻), of which beetroot is one of the densest dietary sources. Oral nitrate is reduced in the mouth by commensal bacteria to nitrite (NO₂⁻), which the body further reduces to nitric oxide (NO) under low-oxygen, low-pH conditions — precisely what occurs in working muscle Lundberg 2008. Nitric oxide is a vasodilator and signaling molecule that improves mitochondrial efficiency, oxygen delivery, and contractile function Jones 2014.

“Dietary nitrate supplementation reduces the oxygen cost of submaximal exercise by 3–5% and improves time-trial performance by 1–3% in untrained-to-moderately-trained adults. The effect is most consistent for events lasting 5–30 minutes.”

— Jones, Sports Med., 2014 view source

What the evidence shows

Two seminal studies established the field. Bailey 2009 (a randomized crossover in healthy men) showed that 6 days of 500 mL/day beetroot juice reduced the oxygen cost of cycling by ~5% and increased time-to-exhaustion by 16% Bailey 2009. Lansley 2011 then showed that a single ~8.4 mmol nitrate dose taken 2.5 hours before a 4 km and 16.1 km cycling time-trial improved performance by ~2.8% and ~2.7% respectively Lansley 2011.

The 2019 Domínguez meta-analysis pooled 80 trials and reported a small-to-moderate beneficial effect on endurance time-trial performance, with the strongest signal in trained recreational cyclists and runners doing efforts 5–30 minutes long Domínguez 2017. The 2017 Mc Mahon umbrella review reached the same conclusion Mc Mahon 2017.

What it doesn’t do, or doesn’t reliably do:

• Sprint events under ~1 minute: mixed; some studies show small benefit, most show null.
• Ultra-endurance over ~60 minutes: signal weakens; nitrate stores deplete and other limiters dominate.
• Pure strength: 1RM bench press, squat — mostly null. Beetroot is not a strength aid.
• Elite athletes: smaller and more variable response. The world-class endurance athlete has already optimized many of the same pathways through training.
• High-intensity intermittent (team sports): emerging positive data, but less consistent than cycling/running TTs.

Dose, timing, and form

Don’t use antibacterial mouthwash before training

The conversion of nitrate to nitrite happens in the mouth by oral bacteria. Antibacterial mouthwash (chlorhexidine, alcohol-based mouthwashes) blocks this step and abolishes the performance benefit Govoni 2008. Athletes loading beetroot for an event should avoid antibacterial mouthwash for the loading period.

Whole-food nitrate sources

You don’t have to drink beetroot juice. Comparable nitrate doses can come from food, though it takes more volume:

Who benefits most

Other (non-performance) effects worth knowing

• Blood pressure: dietary nitrate modestly reduces resting systolic blood pressure (~3–5 mmHg). Useful side benefit for healthy adults; relevant interaction concern for those on antihypertensives Siervo 2013.
• Endothelial function: improves flow-mediated dilation in adults with cardiovascular risk factors.
• Cognitive performance: some studies suggest small acute improvements in reaction time and executive function; data less robust than performance literature.
• Beeturia: red urine and stool from betacyanin pigments. Harmless but startling on first use. Doesn’t indicate efficacy.

Safety, side effects, and interactions

• GI upset: occasional bloating, mild diarrhea at higher doses (~10+ mmol/day). Usually resolves with dose reduction.
• Lower blood pressure: be cautious if already hypotensive or on medications that lower BP. Beetroot can additively reduce BP.
• Drug interactions: nitrate medications (isosorbide, nitroglycerin), PDE-5 inhibitors (sildenafil/Viagra family), and aggressive antihypertensives can compound vasodilation. Discuss with prescriber before chronic use.
• Pregnancy: dietary amounts (a beet salad) are fine; supplemental high-dose juice is understudied. Default to dietary sources only.
• Kidney stones: beets are high in oxalate. People with calcium-oxalate stone history should not load with concentrated beet juice daily.
• Children: high-nitrate vegetables fine in normal dietary amounts; supplemental beet shots are not studied for children.

A practical protocol for a recreational endurance athlete

Test it in training first. Not on race day. Some people have GI sensitivity; a 5K time trial or training session is the right place to find out.

Practical takeaways

• Beetroot juice is a real, evidence-backed ergogenic aid — one of few “natural pre-workouts” with replicated peer-reviewed support.
• Effect size: 1–3% time improvement for endurance events 5–30 minutes long. Modest but real.
• Optimal dose: 6.4–12.8 mmol nitrate, 2–3 hours before exercise. One concentrated “shot” or 500 mL juice.
• Most reliable in recreational endurance athletes; weaker in elites, sprinters, and pure-strength athletes.
• Don’t use antibacterial mouthwash during loading — it abolishes the effect.
• Side effects mild: red urine, occasional GI upset, modest BP reduction. Caution on nitrate medications.
• Whole-food alternatives: arugula, spinach, beets deliver comparable nitrate at higher volume.

Strength, power, and the resistance-training question

The endurance evidence for beetroot is the strongest part of the story, but a lot of gym-goers want to know whether dietary nitrate does anything for lifting, jumping, or sprinting. Here the honest answer is "mostly no, with a couple of interesting exceptions" — and the exceptions are exactly the sort of thing that gets overstated in supplement marketing.

The mechanistic case for a strength effect is real but indirect. Nitric oxide raises blood flow and may improve calcium handling and the speed of force development specifically in type II fibres — the fast-twitch muscle fibres recruited for explosive, high-force work. Because those fibres sit in a lower-oxygen environment, the conditions that convert nitrite to nitric oxide are theoretically more favourable there. That is the lab rationale, and it is why researchers keep testing nitrate for power.

When you look at the controlled human trials, though, the signal is weak. A 2025 randomised dose-response study gave 18 resistance-trained men beetroot juice at four nitrate doses (up to 24 mmol — well above the standard endurance dose) and measured vertical jumps, barbell back squats, and bench press. Plasma nitrate and nitrite rose neatly with dose, confirming the supplement was working biochemically, yet the researchers found that "dietary nitrate does not impact resistance exercise performance at any of the doses assessed" Tan 2025. In other words, more nitrate did not buy more strength or power, even at triple the usual dose.

A 2020 systematic review of weightlifting trials is slightly more encouraging but far from a green light. Of only four eligible studies, two found that nitrate increased aspects of upper-body performance — chiefly more bench-press repetitions to failure and higher bar velocity — while lower-body results were inconsistent San Juan 2020. The authors describe nitrate as holding "promise" for weightlifting, but a four-study evidence base with conflicting lower-body findings is preliminary, not settled. The most reasonable reading of the two together: any resistance-training benefit, if it exists, is small, probably limited to high-repetition muscular-endurance sets rather than one-rep-max strength, and not something to count on.

Sex differences are another open question, because most early trials enrolled men. A 2025 meta-analysis pooling nine trials in 114 healthy young women found a statistically significant but modest improvement in muscular power (a moderate-certainty effect), while strength and sprint performance showed small, non-significant changes Meng 2025. The takeaway for the gym is consistent across sexes: beetroot is a tool for short-duration endurance, not a strength supplement. If your goal is a bigger squat, your time and money are better spent on progressive overload, protein, and creatine.

Why some people don't respond: the oral microbiome

One of the most practically important facts about beetroot is also one of the least advertised: a meaningful share of people are non-responders. They take the same dose, at the same timing, and get little or no rise in blood nitrite or measurable benefit. The leading explanation is not the muscle but the mouth.

The nitrate-to-nitric-oxide pathway depends on a hand-off you cannot do without: roughly a quarter of swallowed nitrate is re-secreted into saliva, where nitrate-reducing bacteria living mostly in the deep grooves on the back of the tongue convert it to nitrite. Only then can the body finish the job and produce nitric oxide. Because those bacterial communities vary enormously from person to person, the oral microbiome is now considered a primary source of the inter-individual variation in how people respond to beetroot. A 2025 trial that gave older adults beetroot juice for four weeks found it reshaped the oral microbiome (more Neisseria, fewer Veillonella) but not the gut microbiome, and that the abundance of those nitrate-reducing bacteria correlated with how much plasma nitrate and nitrite each person achieved Fejes 2025. If your tongue is not well colonised with the right bacteria, the supplement has nowhere to be activated.

This is also why the article's warning about antibacterial mouthwash matters so much: chlorhexidine and similar rinses wipe out exactly these bacteria, and doing so sharply blunts the nitrite rise after a nitrate load Govoni 2008. The same logic raises a tempting question about over-cleaning the tongue — but the evidence here is nuanced, not a simple "scrape less." A controlled study of tongue-cleaning frequency found that the practice reshaped the tongue microbiome, yet daily cleaning actually enriched some beneficial nitrite-reducing species, and plasma nitrite did not differ significantly between cleaning groups Tribble 2019. So the defensible, evidence-based advice is narrow: skip antibacterial mouthwash on the days you want beetroot to work, and don't expect ordinary oral hygiene to be the problem. If you have tested beetroot honestly in training and felt nothing, you may simply be a biological non-responder — and that is a known, normal outcome, not a dosing error.

Is the nitrate in beets the "bad" kind? Sorting out the cancer question

Many readers hesitate at the word "nitrate" because they associate it with processed meats and cancer warnings. It is a fair worry, and it deserves a straight answer rather than a brush-off. The short version: the nitrate in beetroot and leafy greens is not the public-health concern that the nitrite added to bacon and deli meat is, and the difference comes down to what else is in the food.

Vegetables supply the large majority of dietary nitrate — roughly 80–85% of typical intake — while processed meat contributes only a small fraction Karwowska 2020. The health concern with nitrate and nitrite is not the compounds themselves but the N-nitrosamines that can form when nitrite reacts with certain amines (abundant in cooked, cured meat) under the right conditions; some N-nitrosamines are carcinogenic, and the International Agency for Research on Cancer classifies ingested nitrate or nitrite "under conditions that result in endogenous nitrosation" as probably carcinogenic. The decisive variable is the food matrix. Vegetables come packaged with vitamin C and other antioxidants, which intercept nitrite before it can form nitrosamines; one review notes that nitrosamine formation was completely inhibited when the ratio of antioxidants to nitrite was high enough Karwowska 2020. Processed meats lack that built-in protection and add the amines, which is why the same review reports that animal-source nitrate, but not plant-source nitrate, has been positively associated with some cancers. In a beet, the nitrate arrives with the very compounds that steer it toward beneficial nitric oxide rather than harmful nitrosamines.

None of this is a licence for unlimited intake, and the data are observational, so cause and effect cannot be proven from the food-source comparison alone. But the practical conclusion is reasonable and widely shared in the nutrition literature: nitrate from beetroot, spinach, and arugula belongs in the "eat more vegetables" column, not the "limit processed meat" column. The two should not be lumped together just because they share a chemical name.

Beyond athletes: older adults and clinical populations

Most of this article is written for recreational endurance athletes, but the same nitric-oxide pathway is being studied as a low-cost adjunct in people whose problem is restricted blood flow or stiff arteries — and the early results help frame realistic expectations for healthy readers too.

The most convincing clinical signal so far is in chronic obstructive pulmonary disease (COPD). The randomised, double-blind, placebo-controlled ON-BC trial gave 81 COPD patients with elevated blood pressure 70 mL of nitrate-rich beetroot juice (about 400 mg nitrate) daily for 12 weeks. Compared with a nitrate-depleted placebo, it lowered home systolic blood pressure by roughly 4.5 mmHg and improved six-minute walking distance by about 30 metres — a change large enough to be clinically meaningful — alongside better endothelial function Alasmari 2024. That this used the same modest dose and the same daily-loading pattern recommended for athletes is reassuring: it shows the blood-pressure effect, well established in healthy adults Siervo 2013, can be sustained over months in a patient group.

The evidence is thinner and more mixed elsewhere. In peripheral artery disease — where narrowed leg arteries cause walking pain (claudication) — a 2025 systematic review found only five small randomised trials totalling 64 patients. A couple reported worthwhile gains in pain-free and peak walking time, but others showed no difference from placebo, and the reviewers urged caution given the tiny samples and varied methods Umaña Mejia 2025. The pattern across clinical research mirrors the athletic literature: the underlying dose-response relationship for blood nitrite is well characterised Wylie 2013, the blood-pressure effect is fairly reliable, but the downstream benefits on function are real for some people and absent for others.

The important caveat is that these are treatment populations, not a do-it-yourself recommendation. COPD, peripheral artery disease, and treated hypertension all involve medications and physiology that interact with nitrate's blood-pressure-lowering effect. Anyone with a cardiovascular or kidney condition, or on blood-pressure or nitrate-class drugs, should treat beetroot as something to discuss with a clinician — not as a self-prescribed therapy — even though it is sold as an ordinary juice.

References