Beetroot's performance boost vanishes in trained athletes

Dietary nitrate, most familiar as beetroot juice, is one of the most widely used legal performance aids, and it has credible evidence behind it in recreationally active people. Whether that benefit survives in genuine athletes has been debated for years, since highly trained bodies may already have efficient oxygen delivery, leaving less room for a supplement to add anything. Individual athlete trials have been small and inconsistent, which makes the question hard to settle one study at a time. This analysis set out to answer the athlete question specifically, pooling trials across diverse sports and supplementation protocols.

The authors swept the literature for randomised, placebo-controlled trials of dietary nitrate supplementation in healthy athletes classified as Tier 2 or higher, ending up with 45 trials covering 659 athletes. They pooled effects on six outcomes: peak power, mean power, maximal oxygen uptake, heart rate, blood lactate and rating of perceived exertion. Random-effects models generated the pooled estimates, and the team ran subgroup analyses by sport type and exercise type, sensitivity analyses, and checks for publication bias to see whether missing studies might be skewing the picture.

No statistically significant pooled effect emerged for any of the six outcomes. An exploratory subgroup analysis found a positive effect on peak power in male-only studies (g = 0.29), but the comparison against mixed-sex studies was not itself significant, so it remains a hint rather than a finding. Beetroot and nitrate salts did not differ on maximal oxygen uptake, and when a correction for publication bias imputed five missing studies, that estimate fell to zero. Subgroups spanning endurance, intermittent team sports, and strength and power work showed no significant differences either.

This lands firmly on one side of a long-running split: nitrate improves performance in recreationally active people, yet trials in highly trained populations have tended to look flatter, and this pooled analysis of athletes agrees with the flatter picture. The authors are careful to note that the absence of statistically significant effects should not be read as definitive evidence of no effect. They flag vascular endothelial function in high-performance athletes as a mechanism worth further study, and the possible male-only peak power signal is an unconfirmed loose end. Why training status appears to blunt the response remains the central open question.

If you compete at a high level, this is a reason to hold beetroot shots and other nitrate products to a sceptical standard: across 45 trials, the pooled effect in athletes was indistinguishable from placebo on every outcome measured. If you train recreationally, nothing here overturns the earlier, more positive evidence in people like you, because this analysis deliberately looked only at athletes. Any real effect in trained competitors, if one exists, appears small and dependent on context rather than a reliable edge.