Performance supplements

Dietary nitrate

Beetroot-derived nitrate can alter oxygen cost and blood pressure; effects vary with fitness and the exercise test.

Small controlled human exercise trials

Practical use

Applying the explained evidence

Where it fits: Beetroot-derived nitrate can alter oxygen cost and blood pressure; effects vary with fitness and the exercise test.
Put the information into practice: Less oxygen used at a fixed workload, longer time to exhaustion and faster race completion are distinct outcomes. The evidence below measures the first two, not a universal performance percentage.
Connect evidence to your training: Specify the outcome you want to improve and a repeatable way to measure it. Check whether the study participants, activity and product match the claim; avoid crediting one supplement for changes made alongside several training or diet changes.
Keep this limit in view: The runner study found different oxygen-cost responses by baseline fitness.

Six-day beetroot crossover experiment

Fitness-dependent oxygen-cost trial

Overview

Dietary inorganic nitrate is studied as a precursor in nitrate–nitrite–nitric-oxide biology. A nitrate-rich beetroot preparation is not interchangeable with every beet product or a prescription nitrate medicine.

Risks and limitations

Blood pressure changed in the controlled trial. That deserves context in someone already prone to low readings or taking medicines. These short experiments do not establish a complete interaction profile or long-term safety of concentrated preparations.

How to read this

Less oxygen used at a fixed workload, longer time to exhaustion and faster race completion are distinct outcomes. The evidence below measures the first two, not a universal performance percentage.

Research explained

Exercise economy and tolerance

Who was studied

Eight men aged 19–38; double-blind six-day crossover experiment.

Time to exhaustion: beetroot: 675 seconds
Time to exhaustion: placebo: 583 seconds

What was found

Severe-exercise time to exhaustion averaged 675 seconds with beetroot versus 583 with placebo. Systolic pressure averaged 124 versus 132 mmHg. Moderate-exercise oxygen-uptake gain was lower.

What it cannot establish

Very small sample; the comparator differed from modern nitrate-depleted beetroot placebos. Exhaustion time is not a time-trial performance estimate.

Read the original study

Baseline fitness mattered

Who was studied

Low- and high-fitness male runners; four-day double-blind crossover loading periods.

What was found

Lower-fit participants used less oxygen at 45% and 60% of maximal aerobic capacity. The higher-fit group did not show the same effect; perceived exertion and heart rate did not differ.

What it cannot establish

The accessed abstract omits sample size. Fitness subgroup findings are not a universal prediction for elite athletes.

Read the original study

Lower oxygen cost is not a bigger engine

Using less oxygen at a given work rate is an economy measurement; it does not necessarily mean maximal oxygen capacity increased.

Supporting source

An impressive percentage needs its test

A longer exhaustion test can yield a large relative difference without implying an equivalent improvement over a fixed racing distance.

Supporting source

Fitness can change the result

The runner study directly limits transfer from less-trained participants to highly fit athletes.

Supporting source

Product identity matters

These trials used specified nitrate-containing preparations. The word beetroot alone does not establish equivalent nitrate exposure.

Supporting source

What should remain unscored

No trial here measures the net risk of combining nitrate supplements with performance drugs or medicines.

Supporting source

Claims versus findings

Not established

Every athlete receives the same endurance improvement.

The runner study found different oxygen-cost responses by baseline fitness.

Check the evidence

Common questions

Does the result prove faster competition times?

Not directly. The principal positive study measured fixed-load time to exhaustion.

Source

Sources

Six-day beetroot crossover experiment

Fitness-dependent oxygen-cost trial

Sources checked 2026-09-28.

General education; not a personal treatment plan.