I’m not exactly what you would call a “betting man,” but I would wager some serious cash that you’ve heard of beetroot, dietary nitrates, or nitrites by now. If not, then here’s a primer on what many people consider the next “Holy Grail” with regards to performance and health-enhancing supplement ingredients for the cardiovascular system. How will ingredients that are touted to promote anaerobic and aerobic muscular endurance benefit the power athlete? Great question. Before we can address that, let’s look into what beetroot really brings to the table.
Beetroot, along with many other low-calorie tuber veggies, like radish and turnips, as well as leafy veggies like spinach, rocket, lettuce, and swish chard all contain high concentrations of inorganic nitrate (NO3-).
Nitrates, and it’s reduced form, nitrites, are also produced in small quantities within the body, and are a major part of the regulation of cardiovascular health by altering blood pressure, blood flow, and vasodilation. Regardless of whether you supplement with sodium nitrate, dietary nitrates from beetroot or other fruits and veggies, or just increase the amount of nitrate-rich foods in your diet, the concentration of nitrates and nitrites increases within your body, though the specific health benefits of each nitrate-type may differ.
The presence of nitric oxide, a metabolite of inorganic nitrate, in deoxygenated blood has the effect of vasodilation (increase cross-sectional area) within the blood vessels. This not only reduces blood pressure, it also allows for more oxygenated blood to follow up and deliver necessary nutrients and then carry away waste products like CO2.
The short version of all that: Nitrates/nitrites convert to nitric oxide, which improves blood flow and circulation. The more efficient circulation and blood flow, the less oxygen cost to perform a specific task. So, in theory, the more dietary nitrates in your diet, the more nitric oxide produced within the body, the more efficient and effective blood flow during rest and training. Let’s take a look at a few studies to see if this theory holds any weight.
“The more dietary nitrates in your diet, the more effective your blood flow will be in training”
Endurance/Aerobic Exercise
Research shows that supplementing with a dose of nitrates (.1mmol/kg) that is also achievable through a veggie rich diet can have significant reductions in oxygen cost during submaximal (aerobic) exercise by 5% with a 7% increase in energy efficiency. The interesting part is that these changes in V02 (oxygen consumption) happen without affecting heart rate, lactate production, or many other variables related to aerobic exercise.
Studies looking at both running and cycling performance when supplementing with dietary nitrates show a slight increase in time trial performance as well as increases in time to exhaustion. Consuming at least 500 mg nitrate from beetroot (baked and then juiced) decreased 5k time-trial completion by 41 seconds. Consumption of 140 mL of beetroot juice was unable to significantly improve cycling performance but consuming 500 mL of beetroot juice resulted in a 2.8% reduction in time for the first 4 km of a 16.1 km time trial, and a 2.7% improvement overall. Studies on time to exhaustion have shown that 500 mL of beetroot juice results in a 15.7 % increase in comparison to a placebo.
Be the King or Queen of your next race with Nitrate Supplementation
High-Intensity Intermittent Exercise
A study looking into the effects of beetroot supplementation on 20m intermittent sprints showed that consuming 490 mL of beetroot juice increased performance by 4.2% in comparison to a placebo. For this reason, the authors of the study recommend beetroot juice supplementation for team sports athletes.
Anaerobic/Power Exercise
A study published in the Pflugers Archiv: European Journal of Physiology in 2013 sought to determine the effects of nitrate supplementation on power output since previous research has suggested that supplementing with nitrates increases nitric oxide (NO) bioavailability, but an increase in NO may actually reduce muscle contraction power.
The study concluded that supplementing with nitrates does not reduce muscle contraction power, but it does reduce the amount of phosphocreatine that is used during maximal muscle contractions. Though there may be no performance benefit from supplemental or dietary nitrates with regard to power output, the reduction in phosphocreatine use may mean shorter recovery times between repeat bouts of high intensity muscle contractions.
Though the performance benefits may not be as profound for the power athlete in comparison to endurance or aerobic based conditioned athletes, since most training for sports is similar to intermittent sprinting, supplementing nitrates or increasing the amount of nitrate-rich vegetables in your diet may provide significant increases in training intensity and volume. This potential increase in intensity and volume may provide significant improvements in long term training adaptations and therefore increases in performance and competition. The next question research may attempt to answer is whether the health benefits of consuming more nitrate-rich vegetables can be replicated by a dietary nitrate supplement. At this point, I think that even if there is no performance benefit for the power athlete, the health and circulatory benefits from consuming more nitrate-rich vegetables is worth it. Just like anything and everything else, too much of a good thing can be a bad thing. Excessive consumption of beetroot can lower blood pressure to unsafe levels. We all know that we should eat more veggies, but now we know that specific vegetables can have actual performance and recovery benefits. So don’t skip the beets and spinach!
About Kevin Kuhn
Kevin Kuhn, M.S.Ed., CSCS, MFS is a Kinesiologist and Sport Nutrition Coach in Dallas, Texas. Before moving to Dallas in 2012, Kevin was the head strength & conditioning coach for the Indiana Invaders professional running club in Indianapolis, Indiana. Kevin specializes in athletic performance with great interest and experience in running-specific strength & conditioning, corrective exercise, and exercise and sport nutrition. Kevin has been certified by the National Strength & Conditioning Association as a Certified Strength and Conditioning Specialist (CSCS) and as a Master Fitness Specialist by the Cooper Institute.
Sources
Bailey SJ, Winyard P, Vanhatalo A, et al. Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. J Appl Physiol. 2009;107(4):1144-55.
Beet Root – Scientific Review on Usage, Dosage, Side Effects https://examine.com/supplements/beet-root/#ref20
Fulford J, Winyard PG, Vanhatalo A, Bailey SJ, Blackwell JR, Jones AM. Influence of dietary nitrate supplementation on human skeletal muscle metabolism and force production during maximum voluntary contractions. Pflugers Arch. 2013;465(4):517-28.
Lansley KE, Winyard PG, Bailey SJ, et al. Acute dietary nitrate supplementation improves cycling time trial performance. Med Sci Sports Exerc. 2011;43(6):1125-31.
Larsen FJ, Weitzberg E, Lundberg JO, Ekblom B. Effects of dietary nitrate on oxygen cost during exercise. Acta Physiol (Oxf). 2007;191(1):59-66.
Murphy M, Eliot K, Heuertz RM, Weiss E. Whole beetroot consumption acutely improves running performance. J Acad Nutr Diet. 2012;112(4):548-52.
Siervo M, Lara J, Ogbonmwan I, Mathers JC. Inorganic nitrate and beetroot juice supplementation reduces blood pressure in adults: a systematic review and meta-analysis. J Nutr. 2013;143(6):818-26.
Wylie LJ, Mohr M, Krustrup P, et al. Dietary nitrate supplementation improves team sport-specific intense intermittent exercise performance. Eur J Appl Physiol. 2013;113(7):1673-84.