How Beetroot Juice Enhances Cycling Performance: The Power of Nitric Oxide

Nitric Oxide (NO) and Exercise Performance

Nitric oxide is an important signaling molecule in the human body, playing multiple roles during exercise:

1. Vasodilation: Increases blood flow, improving oxygen supply to muscles
2. Mitochondrial efficiency: Reduces the oxygen cost (less oxygen needed for the same power output)
3. Muscle contraction efficiency: Influences calcium handling, improving the energy efficiency of muscle contractions
4. Glucose uptake: Promotes glucose uptake and utilization by muscles

Mechanisms of Beetroot Juice

The Nitrate-Nitrite-Nitric Oxide Pathway

Beetroot juice is rich in inorganic nitrate (NO₃⁻). The conversion process after ingestion is as follows:

Beetroot juice (NO₃⁻)
    ↓ Reduced by oral bacteria
Nitrite (NO₂⁻)
    ↓ Gastric acid + tissue enzymes
Nitric oxide (NO)
    ↓
Vasodilation + Improved mitochondrial efficiency + Improved muscle function

Important detail: This pathway depends on specific bacteria in the oral cavity (mainly Veillonella), which are responsible for reducing nitrate to nitrite. This is why:

• ❌ Using antibacterial mouthwash (e.g., Listerine) completely blocks the effect
• ❌ Spitting out beetroot juice instead of swallowing reduces conversion efficiency
• ✅ Letting the juice sit in the mouth for a few seconds before swallowing may increase conversion

Review of Scientific Evidence

Key Studies

Lansley et al. (2011), Medicine & Science in Sports & Exercise

• Beetroot juice supplementation improved 4 km and 16.1 km time trial performance by 2.8% and 2.7%, respectively
• Oxygen consumption was reduced by approximately 3% (at the same power output)
• This is the most classic beetroot juice study in cycling

Cermak et al. (2012), International Journal of Sport Nutrition (Systematic Review)

• Pooled 17 studies, confirming that nitrate supplementation can improve exercise performance by approximately 1-3%
• The effect is most pronounced during sustained exercise at submaximal intensities (e.g., Zone 3-4)

Thompson et al. (2015), Applied Physiology, Nutrition, and Metabolism

• In high-intensity intermittent exercise (simulating road racing attacks), the beetroot juice group improved performance by 3.5%
• Particularly relevant for cyclists: climbing, breakaways, chasing back to the peloton, etc.

Evidence of Diminishing Effects in Highly Trained Athletes

Porcelli et al. (2015), Frontiers in Physiology

• Grouping subjects by VO₂max, they found:
  • Low fitness group (VO₂max < 45): performance improved by 5%
  • Moderate fitness group (VO₂max 45-60): improved by 2.5%
  • High fitness group (VO₂max > 60): improved by only 1%, not statistically significant

Why?

• Highly trained athletes already have high NO synthase (eNOS) activity
• Their mitochondrial efficiency is already near its limit
• The marginal benefit of vasodilation diminishes

But this does not mean elite cyclists should not use it—a 1% improvement is still meaningful in a competitive setting, and at high altitude or in hypoxic conditions, elite athletes are more likely to benefit from beetroot juice (because NOS activity decreases under hypoxia).

Ingestion Protocols: Acute vs. Chronic

Acute Protocol (Single Use)

Parameter	Recommendation
Dose	6-8 mmol nitrate (approximately 500 ml of regular beetroot juice, or 1-2 servings of concentrate)
Timing	2-3 hours before exercise (plasma nitrite peaks 2-3 hours after ingestion)
Notes	Do not use mouthwash, do not take with high-dose vitamin C

Chronic Protocol (Continuous Supplementation)

Parameter	Recommendation
Dose	6-8 mmol nitrate daily
Duration	3-7 days (before competition)
Advantage	Provides more stable and potentially greater effects
Race day	Maintain daily dose, ingested 2-3 hours before the event

Research recommendation: Wylie et al. (2013) found that 7 days of chronic supplementation is superior to a single acute dose, recommending a chronic protocol before important races.

Dosing Considerations

• Minimum effective dose: approximately 5-6 mmol nitrate
• Optimal dose: 6-8 mmol (the range used in most studies)
• High dose: 12-16 mmol showed greater effects in some studies, but with increased gastrointestinal risk
• Body weight adjustment: There is currently a lack of research on weight-based dosing, but 0.1 mmol/kg is a preliminary recommendation

Practical Supplementation Options in Taiwan

Product Selection

Product	Nitrate Content	How to Obtain	Approximate Price
Beet It Sport Shot (70 ml)	6.4 mmol/serving	iHerb, Amazon	NT$80-120/serving
Fresh beetroot juice (500 ml)	Approximately 5-8 mmol	Homemade	NT$30-50
Beetroot powder	Varies by brand	Organic food stores	NT$500-800/jar

How to Make Homemade Beetroot Juice

Fresh beetroot (the purplish-red root vegetable) is usually available at traditional markets and organic produce stores in Taiwan.

Ingredients:

• 2-3 fresh beetroots (approximately 300-400 g)
• 1 apple (to improve flavor)
• A few slices of ginger (optional)
• A little lemon juice (optional; be careful not to overdo vitamin C)

Method:

1. Peel and chop the beetroot
2. Put it in a slow juicer or blender together with the apple
3. Strain to extract the juice, yielding approximately 300-500 ml
4. Refrigerate and consume within 2 days

⚠️ Note: The nitrate content of homemade juice varies greatly depending on the beetroot variety, origin, and season. For important races, it is recommended to use a standardized concentrated product (e.g., Beet It Sport Shot).

Side Effects and Precautions

Common Reactions (Harmless)

• Red urine and stool (beeturia): Completely normal, no need to worry
• Mild gastrointestinal bloating: Usually improves after adaptation

Conditions Requiring Caution

• People with low blood pressure should use with caution: The vasodilatory effect of nitrate may further lower blood pressure
• People with impaired kidney function: Nitrate metabolism may be affected; consult a physician
• People using PDE5 inhibitors (e.g., Viagra): The combined vasodilatory effect may be excessive

Interaction with Mouthwash

This is worth emphasizing again: Mouthwash containing chlorhexidine or alcohol kills the nitrate-reducing bacteria in the oral cavity, directly blocking the effect of beetroot juice.

• Avoid antibacterial mouthwash for at least 12 hours before competition
• Brushing with regular toothpaste is fine
• If oral hygiene is needed, use a mouthwash without antibacterial ingredients

Recommended Usage Scenarios

Scenario	Recommendation	Protocol
A-priority target race	★★★★★	Chronic 7 days + acute on race day
High-altitude riding (Wuling, Hehuan Mountain)	★★★★★	Chronic 3-5 days
Important group ride/testing	★★★	Acute single dose
Daily training	★★	Not needed
Recovery ride	★	Not needed

Conclusion

Beetroot juice is one of the few natural supplements supported by solid scientific evidence. Through the nitric oxide pathway, it can reduce the oxygen cost of exercise, improve blood flow, and enhance muscle efficiency. Although the effect may be smaller for highly trained cyclists, it remains worthwhile for key races and high-altitude environments. With low cost, easy availability, and mild side effects, beetroot juice deserves a regular place on every serious cyclist’s supplement list.

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References: Lansley, K.E. et al. (2011). Dietary nitrate supplementation reduces the O2 cost of walking and running. Journal of Applied Physiology; Jones, A.M. (2014). Dietary Nitrate Supplementation and Exercise Performance. Sports Medicine.

Related Reading

• Beetroot Juice and Nitrate Supplementation: A Natural Performance Enhancer for Cycling
• The Exercise Science of Nitrate and Beetroot: A Complete Analysis of the Nitric Oxide Pathway, Endurance Effect Sizes, and Dosing Timing
• Beetroot Juice and Nitrate: A Scientifically Validated Natural Performance Enhancer
• Nitrate and Beetroot Juice: A Vegetable-Based Ergogenic Aid for Improving Exercise Economy