Nitrate supplementation: the training status paradox

The most significant finding from recent research is the inverse relationship between training status and nitrate efficacy. A comprehensive 2020 systematic review analyzing 22 experimental situations across different training levels found:

• Untrained/Recreational athletes: −2.63% to −2.83% performance improvement
• Trained athletes: −0.49% improvement
• Well-trained athletes (VO2 max 60-70): −0.27% improvement
• Elite athletes (VO2 max >70): −0.31% improvement

Statistical analysis showed highly significant differences between training groups (F(2,19) = 11.787, p = 0.001, ω² = 0.533), with the improvement from elite/well-trained to untrained groups reaching 2.51% (95% CI: 1.12-3.91, p = 0.001).

Source: Pałka T, et al. “Effects of Dietary Nitrates on Time Trial Performance in Athletes with Different Training Status.” Nutrients. 2020. https://pmc.ncbi.nlm.nih.gov/articles/PMC7551808/

Cyclist-Specific Studies

Christensen et al. (2013) – The Landmark Null Finding:
Ten highly trained cyclists (VO2 max: 72 ± 4 ml/kg/min) underwent 6 days of beetroot juice supplementation (0.5L/day). Results:

• No improvement in time trial performance (18:20 vs 18:37 min, p>0.05)
• No change in VO2 kinetics or exercise economy
• Plasma nitrate levels elevated (147-159 μM vs 41 μM placebo), confirming absorption

Source: Christensen PM, et al. “Influence of Nitrate Supplementation on VO2 Kinetics and Endurance of Elite Cyclists.” Scand J Med Sci Sports. 2013. https://pubmed.ncbi.nlm.nih.gov/23020760