Dietary Nitrate and Beetroot: Endurance Boost With Blood Pressure Side Benefit
Dietary nitrate — from beetroot, leafy greens, or concentrated shots — is a genuinely evidence-based endurance aid that works through the nitrate → nitrite → nitric oxide pathway, lowering the oxygen cost of exercise. A roughly 80-trial meta-analysis found acute doses improve 4–30 minute time-trial performance by about 1–3%, with bigger gains in recreational athletes than elites, and daily use also lowers blood pressure by around 4–5/2 mmHg. The practical dose is 6–12 mmol nitrate (one 500 mL beetroot shot or 2–3 beetroots) taken 2–3 hours before exercise. The main catches are that antibacterial mouthwash or gum blocks the conversion and should be avoided that day, beeturia (red urine) is harmless, and anyone on nitrate heart medication should coordinate to avoid additive low blood pressure.
The Endurance Evidence
A 2020 meta-analysis in Journal of the International Society of Sports Nutrition analysed 80 trials of dietary nitrate in endurance performance. Acute supplementation (6–12 mmol nitrate, 2–3 hours pre-exercise) improved time-trial performance in events lasting 4–30 minutes by an average of 1–3%. Effects are larger in recreationally trained individuals than in elite athletes (whose baseline NO availability is already high).
Mechanism
Nitrate is reduced to nitrite by oral bacteria (making antibacterial mouthwash and chewing gum inadvertent performance-killers) and then to nitric oxide in hypoxic tissues. NO enhances mitochondrial efficiency, muscle fibre function, and vasodilation. The combined effect is reduced oxygen cost for a given workload.
Blood Pressure and Cardiovascular
Dietary nitrate’s effect on blood pressure is one of its best-supported outcomes. A 2013 meta-analysis in Journal of Nutrition found daily beetroot juice or nitrate supplementation (typically 8 mmol/day) lowered systolic BP by 4–5 mmHg and diastolic by ~2 mmHg. This is comparable to some low-dose antihypertensives and is driven by NO-mediated vasodilation.
Dose and Sources
Performance doses: 6–12 mmol nitrate (400–800 mg) 2–3 hours before exercise. One 500 mL beetroot juice shot or 2–3 beetroots provide this. Concentrated shots (Beet It Sport, BeetElite) standardise the dose. Leafy greens (spinach, rocket, Swiss chard) deliver similar nitrate per meal but slower to titrate.
Cautions and Nuance
Do not use antibacterial mouthwash or chewing gum on the day of nitrate supplementation — oral bacteria are required for conversion. Beetroot turns urine and stool red (beeturia) in roughly 10–15% of people — harmless but startling. People on nitrate medications (GTN spray, isosorbide) should coordinate to avoid additive hypotension.
Sources
- Jones AM, Thompson C, Wylie LJ, Vanhatalo A. "Dietary nitrate and physical performance." Annual Review of Nutrition, 2018;38:303–328. PMID 30130468.
- Siervo M, Lara J, Ogbonmwan I, Mathers JC. "Inorganic nitrate and beetroot juice supplementation reduces blood pressure in adults: a systematic review and meta-analysis." Journal of Nutrition, 2013;143(6):818–826. PMID 23596162.
- San Juan AF, Domínguez R, Lago-Rodríguez Á, et al. "Effects of dietary nitrate supplementation on weightlifting exercise performance in healthy adults: a systematic review." Nutrients, 2020;12(8):2227.