Beetroot juice and performance: what 33 studies found

A 2026 meta-analysis of 33 studies in 519 athletes found that beetroot juice was followed by small to moderate improvements over placebo in sprint performance (standardised mean difference, SMD, 0.38), mean power output (0.43) and VO2 max (0.30). The authors rate the certainty of the evidence as moderate and call the findings hypothesis-generating, needing confirmation.

What did the meta-analysis of beetroot juice find?

Cai et al., Frontiers in Nutrition 2026 searched six databases up to March 2026 for trials of beetroot juice, a natural source of dietary nitrate. Most were randomised crossover trials against placebo. The pooled estimates were SMD 0.38 for high-intensity interval sprints (95% CI 0.17 to 0.59), 0.43 for mean power output (0.21 to 0.64) and 0.30 for VO2 max (0.05 to 0.55).

An SMD expresses a difference in units of spread between people, which lets different tests be combined. Variation between studies was low (I-squared 0 to 11%), and the authors reported no significant publication bias. The VO2 max interval sits closest to zero, so that estimate is the least precise of the three.

How solid is the evidence, and does it apply to everyone?

The authors downgraded certainty to moderate for unclear reporting of randomisation and allocation concealment, and for blinding problems: beetroot juice has a distinctive colour and taste, so participants and staff can often tell it from placebo. Some subgroups held only one or two studies.

By athlete status, the sprint estimate was 0.17 in professionals (95% CI -0.18 to 0.52, not statistically significant) and 0.50 in amateurs, but the formal tests for subgroup differences were not significant.

A separate 2026 meta-analysis of VO2 max alone, Qin and Kim, Frontiers in Nutrition, pooled 38 studies (703 participants) and found SMD 0.24 (95% CI 0.11 to 0.37). The effect was not clearly demonstrated in highly trained athletes (SMD 0.07, 95% CI -0.09 to 0.23), and after adjustment for possible small-study effects the pooled estimate fell to 0.19 (95% CI 0.07 to 0.31). The VO2 max result may therefore depend on who is measured.

The bottom line

• In 33 studies with 519 athletes, pooled results favoured beetroot juice over placebo for sprint performance (SMD 0.38), mean power (0.43) and VO2 max (0.30).
• Certainty was rated moderate, because colour and taste make blinding difficult and randomisation reporting was often unclear.
• A separate VO2 max meta-analysis of 38 studies found a smaller pooled effect (SMD 0.24), not clearly shown in highly trained athletes.