A systematic review and meta-analysis published in Frontiers in Nutrition reports on July 20 that beetroot juice supplementation has a small but significant effect on maximal or peak oxygen uptake during aerobic exercise, particularly among recreationally active individuals.
Researchers in the Republic of Korea reviewed 38 placebo-controlled trials involving 703 participants to assess the impact of beetroot-derived nitrate or beetroot juice on VO2max or VO2peak. The studies, published between 2009 and 2025, included both healthy adults and trained athletes. Most used nitrate-depleted beetroot juice as a placebo. The primary outcome was relative or absolute VO2max or VO2peak measured during incremental aerobic exercise tests.
The analysis found that supplementation with beetroot juice produced a standardized mean difference (SMD) of 0.24 compared to placebo, with a confidence interval from 0.11 to 0.37 and p < 0.001, indicating statistical significance. Both chronic and acute supplementation protocols showed benefits, though chronic use had a slightly larger effect size; however, this did not establish chronic protocols as definitively superior due to higher heterogeneity within those studies.
The largest benefit was observed among recreationally active participants, while no statistically significant improvement was seen in elite or highly trained athletes. Standard doses of nitrate (6.4 mmol to 12.8 mmol) were most effective; lower doses did not yield significant results and higher doses did not show clear additional benefits over standard dosing ranges.
Methodological quality varied across studies: twenty-two were rated at low risk of bias while sixteen raised some concerns according to the Cochrane risk-of-bias tool for randomized trials. Funnel plot analyses indicated mild publication bias; after adjustment for potentially missing studies using trim-and-fill methods, the pooled effect remained significant but attenuated (SMD = 0.19). Certainty of evidence was rated moderate overall—high among recreationally active people but low for highly trained athletes—due partly to an evidence base predominantly composed of male subjects and combined reporting of verified VO2max with VO2peak values.
In summary, the review concludes that beetroot juice supplementation provides a modest improvement in aerobic capacity mainly for recreational exercisers rather than elite athletes, with practical recommendations warranting caution due to moderate certainty levels.
