Does beetroot juice improve exercise performance?
Moderate EvidenceIT DEPENDS
Moderate-to-good evidence supports beetroot juice improving endurance exercise performance via nitric oxide pathways. Benefits are most consistent in recreational athletes performing time-to-exhaustion tasks, with smaller effects in elite athletes.
The Verdict
Moderate-to-good evidence supports beetroot juice improving endurance exercise performance via nitric oxide pathways. Benefits are most consistent in recreational athletes performing time-to-exhaustion tasks, with smaller effects in elite athletes.
What the Evidence Shows
Beetroot juice is rich in dietary nitrate, which the body converts to nitric oxide (NO), a molecule that improves blood flow, mitochondrial efficiency, and muscle contractile function. Meta-analyses consistently show that acute beetroot juice supplementation (providing 5-8 mmol nitrate) improves time-to-exhaustion by 3-5% and time trial performance by 1-3% in moderately trained individuals. The mechanism involves reduced oxygen cost of exercise (improved exercise economy) and enhanced muscle power output at submaximal intensities. Benefits appear most pronounced in activities lasting 5-30 minutes and in recreational rather than elite athletes. Elite athletes may have already optimized their NO pathways through training, reducing the marginal benefit. Acute dosing 2-3 hours before exercise is effective, while chronic supplementation (3-6 days) may provide additional benefits. However, individual responses vary considerably, with some people being non-responders due to oral microbiome differences that affect nitrate-to-nitrite conversion. Antibacterial mouthwash can blunt the effect by disrupting oral bacteria essential for this conversion.
Evidence Quality
4
Meta-Analyses
15
RCTs
3
Observational
Important Caveats
- ⚠️ Elite athletes show smaller or negligible benefits compared to recreational athletes
- ⚠️ Individual variation in response is significant due to oral microbiome differences
- ⚠️ Antibacterial mouthwash can block the nitrate conversion pathway
- ⚠️ Benefits are most evident in endurance tasks lasting 5-30 minutes
Population Studied
Recreational to moderately trained athletes, primarily males aged 18-40; fewer studies in females and older adults
Dosage
500ml beetroot juice or concentrated shots providing 5-8 mmol (310-500mg) dietary nitrate, consumed 2-3 hours before exercise
Duration
Acute effects from single dose; chronic loading protocols of 3-6 days may enhance response
Supporting Studies (2)
Effects of dietary nitrate supplementation on exercise performance: a meta-analysis
Meta-AnalysisHoon MW, Johnson NA, Chapman PG, Burke LM. · Sports Medicine (2013)
Meta-analysis of 17 trials found dietary nitrate supplementation significantly improved time-to-exhaustion performance (effect size 0.79) and time trial performance (effect size 0.43) compared to placebo.
View paper (DOI) →Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans
RCTBailey SJ, Winyard P, Vanhatalo A, et al. · Journal of Applied Physiology (2009)
Beetroot juice supplementation (500ml/day for 6 days) reduced oxygen cost of submaximal exercise by 19% and extended time to exhaustion by 16% compared to placebo.
View paper (DOI) →Contradicting Studies (1)
No improvement in endurance performance after a single dose of beetroot juice in elite cyclists
RCTBoorsma RK, Whitfield J, Spriet LL. · International Journal of Sport Nutrition and Exercise Metabolism (2014)
A single dose of concentrated beetroot juice (140ml, 8.4mmol nitrate) did not improve 1-km or 4-km cycling time trial performance in elite trained cyclists.
Why this disagrees:
Elite athletes may have already maximized nitric oxide-related adaptations through chronic training, leaving minimal room for additional improvement from dietary nitrate supplementation.
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