Can beetroot juice boost exercise endurance?

Beetroot Juice and Exercise Endurance

Yes, beetroot juice can boost exercise endurance, particularly when consumed as an acute dose of 5-9 mmol nitrate (310-560 mg) approximately 2-3 hours before exercise, with the most robust benefits seen in improving exercise economy and endurance performance. 1

Mechanism of Action

Beetroot juice works through its high inorganic nitrate content, which:

• Increases tissue nitrite and nitric oxide levels, reducing the oxygen cost of exercise through enhanced function of type II muscle fibers and reduced ATP cost of force production 1
• Promotes vasodilation and improved blood flow to working muscles, which may delay phosphocreatine depletion during repetitive exercise efforts 2
• Improves muscle power output via faster muscle shortening velocity 2

Evidence-Based Dosing Protocol

Acute Supplementation (Strongest Evidence)

• Consume 5-9 mmol nitrate (310-560 mg) 2-3 hours before exercise for optimal performance benefits 1
• Recent meta-analysis confirms acute supplementation (2-3 hours pre-exercise) produces small but significant improvements (SMD = 0.20) 3
• Higher doses (8.4 mmol) show possibly beneficial effects in highly trained athletes, while moderate doses (4.2 mmol) demonstrate trivial effects 4

Chronic Supplementation

• Prolonged nitrate intake for ≥3 days may also benefit performance, though effect sizes are smaller (SMD = 0.13) compared to acute dosing 1, 3
• Optimal chronic dosing: 8.3-16.4 mmol NO3- (515-1017 mg/day) 3

Performance Benefits by Population

Professional Athletes

• Muscular strength improvements are significant (SMD = 0.27, p = 0.007) in trained athletes 3
• May improve 2000-m rowing performance by approximately 1.6 seconds with 8.4 mmol doses in highly trained rowers 4
• Limited football-specific evidence exists, but improvements in intermittent exercise performance have been documented in amateur players 1

Non-Athletes and Individuals with Obesity

• More pronounced aerobic endurance improvements (SMD = 0.26) compared to athletes 3
• In adults with obesity, beetroot juice improved exercise efficiency by ~7% and time to exhaustion by ~15% 5
• VO2max increased by 4.82% in female endurance athletes (from 35.24 to 36.94 mL·min-1·kg-1) 6

Healthy Adults

• Significant improvements in time to exhaustion (SMD = 0.25) and YO-YO intermittent recovery test performance (SMD = 0.27), though effect sizes remain small 3
• Enhanced minute ventilation, respiratory equivalents, and heart rate responses during exercise 6

Practical Implementation

Food-First Approach

• High nitrate-containing foods provide a practical solution for chronic use: leafy greens (spinach, rocket salad), root vegetables (celery, beetroot) 1
• This approach avoids potential gastrointestinal upset associated with concentrated beetroot juice supplements 1

Timing Considerations

• Peak plasma nitrite concentrations occur 2-3 hours post-ingestion, making this the optimal pre-exercise window 1
• For competitions, plan consumption accordingly to align peak nitrate availability with performance demands 1

Important Caveats and Limitations

Individual Response Variability

• Substantial individual variation exists in response to nitrate supplementation 1
• Athletes should trial beetroot juice during training before using it in competition 1

Side Effects

• Minor gastrointestinal upset is possible, particularly with concentrated juice 1
• Beetroot juice may discolor urine (harmless but noteworthy) 1

Population-Specific Considerations

• Effect sizes are generally small to negligible across most outcomes, with the exception of specific populations (professional athletes for strength, non-athletes for endurance) 3
• Highly trained athletes may experience smaller benefits compared to recreational exercisers due to already optimized physiological systems 4

Quality Assurance

• When using supplements rather than whole foods, choose products screened by third-party testing programs (Informed Sport, Kölner Liste) to minimize contamination risk 1
• These programs do not verify active ingredient content, only absence of prohibited substances 1

Comparison to Other Ergogenic Aids

While beetroot juice shows promise, its effects are modest compared to:

• Caffeine: 3-6 mg/kg body mass shows larger performance benefits 1
• Creatine: Demonstrates more substantial improvements in high-intensity, repeated sprint performance 1