Beetroot Juice Shows Limited Benefits in Aerobic Capacity
A recent systematic review and meta-analysis published in Frontiers in Nutrition assessed the effects of beetroot juice supplementation on maximal oxygen uptake during aerobic exercise. Researchers from South Korea synthesized evidence from 38 placebo-controlled trials published between 2009 and 2025, involving 703 participants. The studies focused on either VO2max or VO2peak as measures of aerobic capacity.
Beetroot juice is noted for its high levels of inorganic nitrate, which is converted in the body to nitric oxide, a compound that plays a crucial role in oxygen delivery and muscle function. This biological basis suggests potential benefits for aerobic performance, although the review found these benefits to be modest.
The meta-analysis revealed a small but significant increase in VO2max or VO2peak in those supplementing with beetroot juice compared to placebo, with a standardized mean difference (SMD) of 0.24. The confidence interval ranged from 0.11 to 0.37, and the p-value was less than 0.001, indicating statistical significance. Moderate heterogeneity among the studies was noted, with an I2 statistic of 48.3%.
Subgroup analyses highlighted that recreationally active participants experienced the most significant improvements, while no statistically significant effects were observed in elite athletes. The dosage of nitrate also influenced outcomes, with standard doses between 6.4 mmol and 12.8 mmol providing the most consistent effects. Both chronic and acute supplementation improved aerobic capacity, though chronic protocols showed slightly better results.
Methodologically, the review employed rigorous criteria, using the Cochrane risk-of-bias tool to evaluate study quality. Twenty-two of the studies were assessed as having a low risk of bias, while 16 had some concerns. Despite these variations, the overall evidence was rated as moderate in certainty, particularly for recreational exercisers.
The implications of these findings suggest that while beetroot juice can modestly enhance aerobic performance in recreational athletes, its benefits for elite sportsmen remain unsubstantiated. The evidence base primarily comprised male participants, and results combined both verified VO2max and VO2peak values, which may affect the generalizability of the conclusions.
