Can this common compound in beet juice help you get stronger?

  • Dietary nitrates are naturally occurring compounds that the body converts to nitric oxide.
  • They are found in a variety of foods, including beet juice and spinach and arugula
  • Research has previously linked higher blood nitrate levels to improved physical performance.
  • A new study finds that nitrate levels in the muscles actually have a large effect on strength.
  • Dietary nitrates can be obtained from foods including beets and dark leafy greens.

Gym-goers and athletes use many different compounds to help boost physical performance—from proteins to branched-chain amino acids.

Another one that has long been linked to improved exercise performance is dietary nitrate, a natural chemical that the body converts to nitric oxide. Research has shown that it can improve muscle and heart function.

Scientists previously thought that dietary nitrate supplements aided physical performance by affecting blood vessels – helping them to dilate so that blood and oxygen could flow.

However, a new one Study Published this month in the journal Acta Physiological, This indicates that nitrates promote activity that also affects another important part of the body.

The researchers wanted to learn more about how our cells use nitric oxide for exercise.

During the study, 10 participants were given potassium nitrate supplements or a placebo. After an hour, they performed 60 contractions of the quads (aka thigh muscles) using an exercise machine.

The researchers found that, compared to a placebo, taking nitrates before exercise increased muscle strength in the quads by 7%.

“Previous studies have shown that, when plasma nitrate and nitric oxide levels increase after nitrate intake, exercise performance improves — and the same was true in this study,” said Andy Jones, PhD, University Professor of Applied Physiology. Exeter and co-author of the study.

However, whereas previous research had primarily linked blood nitrate levels with improved physical exertion, this study showed something different.

“A novel finding was that it was muscle (rather than blood) nitrate levels that were most closely related to improved muscle force production,” Jones shared with Healthline.

To measure the nitrate content in the muscle cells, the researchers took small biopsies of the muscle immediately after the initial exercise session and again at the three-hour mark.

Jones revealed that these biopsies showed that “nitrate levels in muscle (and blood) peak 1-3 hours after ingestion, and remain elevated for several hours before levels decline.”

While muscle strength was not tested again through exercise three hours later, “we would expect to see the same pattern,” he added.

Furthermore, while the study focused on the quad muscles, Jones said he expects the benefits of nitrate supplementation to extend to other muscles as well.

“We chose the leg because we wanted to collect muscle samples, and it’s easier to take biopsies from the thigh than from other places,” he said.

When dietary nitrate enters the body, it does not always remain in its original form.

“When we consume nitrates in the diet, bacteria in the mouth convert some of the nitrates into nitrites,” Steve Grant, a nutritionist specializing in athletic performance in London, UK, revealed to Healthline.

“Then, in the stomach, nitrites are converted to nitric acid,” he continued. “The rest of the nitrates and nitrites are absorbed in the small intestine, and these can also be converted to nitric oxide.”

Nitric oxide is considered especially important when it comes to exercise and physical performance.

“Nitric oxide can affect blood flow and dilation of blood vessels and improve blood flow to skeletal muscle,” Grant noted. “Because of this function, it has also been linked to improving muscle endurance.”

This study confirmed that dietary nitrates taken before exercise can have significant benefits in increasing muscle strength. But how does it affect?

“Nitrates, through nitric oxide, can help improve the efficiency of muscle contraction by reducing the amount of oxygen used during exercise,” Grant shared.

“It’s also been said that nitrates – through the work of nitric acid – improve how muscles contract by increasing intracellular calcium (the trigger of muscle contraction),” he added.

The role of calcium in muscle performance is important, says Samantha Coogan, MS, RDN, CSSD, LD, FAND, program director/lecturer in nutrition sciences at the University of Nevada, Las Vegas’ School of Integrative Health Sciences.

“More free flowing calcium inside the cells increases skeletal muscle myosin light chain kinase (MLCK) activation,” she told Healthline. MLCK is a key process involved in smooth muscle contraction.

“It increases myosin regulatory light chain phosphorylation,” Cooper continued—”phosphorylation is a process essential for cellular storage and energy transfer.”

The result?

“Greater calcium-related contractile sensitivity, which results in twitch force, faster force development, maximal shortening velocity, and maximal force production of the muscle,” she said.

Dietary nitrates can also aid in muscle growth through their effect on protein, says sports nutritionist and personal trainer Holly Roger.

“Nitrogen is found in amino acids, which are considered the building blocks of protein,” she told Healthline. “Protein is essential for muscle growth and repair, which can help boost your workout performance.”

However, previous research has found that this compound can improve other areas of physical performance as well.

“Nitrates increase blood flow, allowing for improved oxygen and nutrient delivery,” shared Roger. “Increased oxygen can lead to better endurance, power output, and overall physical performance,” he explained.

For example, A 2021 meta-analysis 78 studies found that taking dietary nitrate supplements before exercise increased participants’ time to exhaustion and allowed them to cover greater distances.

Cooper revealed that nitric oxide can also have beneficial effects on the heart—which is important for cardiovascular-related performance.

“Nitric oxide is also a key component in heart health and cardiovascular responses such as blood pressure and blood flow,” she said. “The heart itself is a muscle, so we can maximize muscle capacity through adequate nitric oxide intake.”

A 2015 study found that consuming beetroot juice (which is high in nitrates) for three days before exercise enabled participants to perform high-intensity aerobic exercises more efficiently.

Two main approaches can help increase your dietary nitrate and nitric oxide levels.

The first is through diet. According to Grant, some of the best food sources include:

  • Beats
  • Rhubarb
  • spinach
  • Arugula
  • Turnip greens
  • Deal
  • Swiss chard
  • Celery
  • Radish
  • Watercress
  • black
  • Salad

However, he adds, “reasonable amounts may need to be consumed” for the benefits to occur.

It’s also important to note that not all food-based nitrates are created equal. “You may be familiar with nitrates added to foods, such as processed meats, that preserve the color of the food,” Rosner highlighted. “It’s not good for your health and has been linked to cancer and problems during pregnancy.”

Another method, Cooper shared, is through beet-based dietary nitrate supplements. These can be found in the form of pre-workout mixes, concentrated juice shots, capsules, and gummies.

As Jones notes, “For athletes, it’s not easy to consume a salad a few hours before a competition. It’s more convenient to drink concentrated beet juice.”

Remember that supplements are not regulated by the Food and Drug Administration (FDA), and excessive intake of dietary nitrates can potentially cause side effects.

“Always consult a physician and registered dietitian before starting any type of supplement,” Cooper emphasized.

Scientists have long thought that increasing levels of dietary nitrate in the blood helps improve athletic performance.

While this remains a factor, new research indicates that the direct uptake and utilization of dietary nitrate by the muscles has the greatest effect on increasing muscle strength.

The new findings are important, Jones said, because “they show for the first time that higher muscle nitrate concentration (which can be manipulated through diet) is associated with greater force output.”

Ultimately, this knowledge can be beneficial to more than just gym-goers. “This is important for athletes, but possibly also for older people and those with diseases that cause muscle weakness,” Jones added.

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