Does beet juice actually improve athletic performance?

Beetroot juice shots sit at the start line of marathons and the bottom of gym bags for one reason: dietary nitrate, the compound beets are rich in, has one of the more legitimate performance stories in the supplement aisle. It is also one of the more oversold ones, because what works for a recreational runner on a long effort mostly stops working once you're already elite.

What dietary nitrate actually does in the body

Nitrate from beets gets converted in the body, partly by bacteria in the mouth, into nitric oxide, a molecule that widens blood vessels and can make muscles use oxygen more efficiently. At a fixed, submaximal pace, that translates into a real, measurable effect: nitrate supplementation can cut the oxygen cost of exercise by roughly 3 to 5%, according to a review of the research for the Gatorade Sports Science Institute. That is the "makes submax exercise cheaper" effect, and it is the most consistent finding across the literature.

What a big 2025 review found, and what it didn't

A 2025 umbrella review pulled together 20 separate meta-analyses covering 180 studies and found dietary nitrate meaningfully improved time to exhaustion, total distance covered and muscular endurance. It found no significant benefit on time trials, graded exercise tests, VO2 max or muscular strength. In other words, nitrate seems to help you sustain effort longer at a given intensity, not necessarily go faster over a fixed distance or lift more weight, and a separate meta-analysis of HIIT and sprint studies found no benefit to peak or average power output either.

The effective range across these trials is fairly narrow: about 6 to 12 millimoles of nitrate, roughly 250 to 500ml of beetroot juice, taken 2 to 3 hours before exercise. Going above 12 mmol doesn't add more benefit, so there's no case for drinking more.

Why elite athletes barely notice it

The most important caveat, and the one least likely to make it onto a bottle, is who actually benefits. The same 2025 umbrella review found the ergogenic effect was more pronounced in non athletes and recreationally active people than in highly trained ones, likely because elite endurance athletes have already optimized their own oxygen delivery systems. An earlier meta-analysis put numbers on that gap: a small but real effect in recreational exercisers, versus an effect in athletes with a VO2 max above 65, a marker of elite endurance fitness, too small to rule out chance. If you already train with structured endurance sessions like zone 2 cardio week after week and compete at a high level, beet juice is unlikely to move the needle much further.

The effect isn't identical for everyone either

Even within non-elite groups, the benefit doesn't apply evenly. A meta-analysis that broke results out by sex found no statistically significant performance benefit in women specifically across the studies it pooled, a gap researchers describe as an open question rather than a settled no. A separate head-to-head trial compared recreational cyclists, competitive speed skaters and Olympic-level athletes after the same nitrate dose and found all three groups showed a similar rise in blood nitrite, the marker nitrate gets converted into, yet none of them ran or rode measurably faster. Getting more nitrate into the blood, in other words, doesn't automatically translate into a better stopwatch time, which is the detail most bottles leave out.

What it costs you, safety-wise

Dietary nitrate is cheap and generally well tolerated. The most common side effects are harmless but noticeable: beeturia, pink or red urine, and reddish stool show up in a meaningful share of people in some trials, along with occasional bloating or GI upset. There isn't strong published evidence yet on how it interacts with blood pressure medication, so it's worth a quick conversation with a doctor if you're on one, rather than assuming it's risk free.

Our take

The underlying nitrate research is real and the Exeter lab that produced much of it has built a genuinely large body of evidence. What that evidence actually says is narrower than the marketing: a small, real boost to sustained endurance effort in recreational exercisers, and very little left to gain once you're already elite. If you're pushing through a long, steady effort, a beetroot juice shot beforehand is a low-cost, low-risk thing to try. If you're hoping it wins you a sprint or a single hard time trial, don't expect much.

This is general information, not medical advice. Talk to a clinician before changing anything, especially if you are pregnant, nursing, or managing a condition.