Beet Supplements for Endurance: The Proven Edge

For endurance athletes looking for a natural, legal performance edge, beet supplements for endurance have become one of the most researched and validated options. The science behind them is compelling. It connects directly to one of the most fundamental factors in athletic performance: how efficiently your body delivers and uses oxygen.

What Makes Beets Different

Beets are one of the richest dietary sources of natural nitrate — a compound found in many vegetables, but in unusually high concentrations in beetroot.¹ That matters because of what the body does with nitrate once it’s consumed.

When you eat beets or drink beetroot juice, naturally occurring nitrate (NO3) is absorbed and converted into nitrite (NO2) by bacteria in your mouth. The nitrite then travels to the stomach and bloodstream, where it becomes nitric oxide — NO.²

Nitric oxide is one of the body’s most important signaling molecules. One of its key functions is vasodilation — the relaxation and widening of blood vessels — which directly increases blood flow throughout the body. More blood flow means more oxygen reaching the muscles that need it, and faster removal of the waste products that cause fatigue.³

The Oxygen-Nitric Oxide Connection

For decades, researchers believed the body could only produce nitric oxide one way — by chemically converting the amino acid L-arginine. But this reaction requires oxygen, which is in short supply during intense exercise. That led scientists to assume nitric oxide played only a minor role in athletic performance.

Then in the 1990s, researchers discovered a second pathway that does not need oxygen to produce NO. This one starts with dietary nitrate — the kind found naturally in vegetables like beets. This was a significant finding. It meant that even during high-intensity exercise, when oxygen is scarce in working muscles, the body could still generate nitric oxide from food sources like beets and trigger the blood-flow benefits that support performance.⁴

This discovery changed how sports scientists thought about nutrition and endurance — and it opened the door to a substantial body of research on beet supplements specifically.

What the Research Shows

The landmark study in this field was conducted at the University of Exeter in 2009 and led by Professor Andy Jones. Researchers found that consuming beetroot juice for three days produced a 16% increase in time-to-exhaustion during high-intensity exercise.⁵ The reason was a reduction in the “oxygen cost of exercise” — meaning athletes could produce the same power output while using less oxygen. Their muscles were simply working more efficiently.

Research that followed confirmed and expanded on those findings. A systematic review published in Nutrients concluded that beet supplements can improve cardiorespiratory endurance by increasing efficiency, enhancing performance in both short and long runs, and extending time-to-exhaustion at submaximal intensities.⁶

A 2024 review comparing different nitrate sources found that beetroot juice may offer advantages beyond its nitrate content alone — including reducing the oxygen cost of high-intensity exercise, amplifying the benefits of training, and improving recovery from muscle-damaging exercise.⁷

A 2026 study of amateur triathletes found that beet nitrate supplementation increased nitric oxide levels, widened blood vessels, improved oxygen delivery to muscles, and allowed athletes to do the same work with less oxygen.⁸

Dietary nitrate from beets has also been recognized by the International Olympic Committee as one of four safe, legal, and effective supplements — alongside caffeine, creatine, and bicarbonate — with evidence supporting performance benefits in both endurance sports and high-intensity sprint events.⁹

How Oxygen and Beet Supplements Work Together

The connection between beet supplements and endurance-related oxygenation runs deeper than vasodilation alone. Research has identified several ways in which the nitric oxide generated from dietary nitrate improves the relationship between oxygen and muscle performance.

Improved oxygen delivery: By widening blood vessels, NO increases the volume of oxygenated blood reaching working muscles during exercise. This is especially important in endurance events where sustained oxygen delivery determines how long muscles can maintain output before fatigue sets in.¹⁰

Reduced oxygen cost: Research has consistently found that dietary nitrate reduces the oxygen cost of performing a given amount of work — essentially improving the efficiency of aerobic metabolism. The same physical effort requires less oxygen input.¹¹

Lactic acid and recovery: When muscles don’t receive enough oxygen to match the demands of exercise, they shift to a backup energy mode and begin producing lactic acid — the compound responsible for the burning sensation in fatigued muscles. Improvements in oxygen delivery help delay this shift, extending endurance before the lactic acid threshold is reached. After exercise, oxygen is also needed to clear the lactic acid that has built up. Better oxygen availability — supported in part by improved circulation via NO — accelerates post-exercise recovery.¹²

Mitochondrial efficiency: Research has found that nitric oxide also improves mitochondrial efficiency — the tiny structures within muscle cells that convert oxygen and fuel into ATP, the energy molecule that powers muscular effort. More efficient mitochondria mean more energy produced per unit of oxygen consumed.¹³

A Real-World Example

Long-time natural products industry executive Mark Becker completed his 100th marathon — the Los Angeles Marathon — on March 18, 2012, finishing the 26.2-mile course in 5:16:53. Over nearly three decades, Becker had completed more than 150 Olympic-distance or longer triathlons, 100 marathons, and countless other events, including ultra-marathons and open-water swims.

Becker has been outspoken about the role of nitric oxide in his training. “Nitric oxide has had a profound impact on my success because it’s responsible for blood flow, oxygen delivery, glucose uptake, and muscle velocity,” he has said. “When I train and race, nitric oxide opens the blood floodgates, which promotes increased blood flow and oxygen. This significantly increases my endurance and recovery.”

His experience aligns closely with what the research confirms: nitric oxide — whether from food or supplementation — plays a direct role in the oxygen delivery that drives endurance performance.

Timing and Practical Considerations

Research suggests that the timing of beet supplementation matters. Studies have found that taking beet supplements two to three hours before exercise produces significant performance benefits, as does a loading approach of three or more consecutive days before a race or event.¹⁴

One practical note: research has found that using antibacterial mouthwash before consuming beet supplements can significantly reduce their effectiveness. The mouth bacteria responsible for converting nitrate to nitrite are eliminated by antibacterial mouthwash, and without that conversion, the downstream chain that produces nitric oxide is interrupted. For athletes using beet supplements for performance, avoiding antibacterial mouthwash in the hours around supplementation is worth keeping in mind.¹⁵

The Bottom Line

Research on beet supplements for endurance has grown significantly since the first Exeter study in 2009. What began as a surprising finding about beetroot juice has developed into one of the most well-supported areas of sports nutrition science. For endurance athletes seeking a natural, research-backed way to enhance oxygen delivery, delay fatigue, and recover faster, beet supplements remain among the most compelling options.

Also Consider

If you are looking for additional support for your body’s oxygen levels, OxygenSuperCharger™ is a bio-available liquid oxygen supplement that provides stabilized oxygen directly to the body. You can read more about the clinical research supporting ASO® technology on our Research and Studies page.