There has been a lot of hype surrounding benefits of athletes consuming beetroot juice, and rightfully so. Although research has shown consistent beneficial effects of consuming beetroot juice in areas such as brain and muscle function, more recently questions are being answered regarding what type of activity it improves the most and why. So what’s so magical about beets? It may just be me, and everyone else I have ever met, but beets don’t taste very good; kind of like grass. But, with the undeniable benefits and minimal negative side effects, athletes are running out of excuses not to try it out.
The Magical Ingredient: Nitrate
The magical ingredient in beetroot juice is nitrate. Beetroot makes nitrate from nitrogen gas in the earth’s soil. When you consume beetroot juice the nitrates are absorbed and attach to plasma headed for your salivary glands. The bacteria in your saliva transforms nitrate into nitrite, which is then delivered to your digestive system for absorption after you swallow. Plasma nitrite flows through the blood stream and is transformed to nitric oxide, supplemental oxygen, and it’s ready for action!
Beetroot Juice Decreases Blood Pressure and Increases Blood Flow, Increasing a Metabolic Threshold and VO2 max
During aerobic exercise our muscle tissues use inhaled oxygen for metabolic pathways to produce energy. When you increase your exercise intensity and work anaerobically, oxygen is no longer readily available for these energy-producing pathways causing your tissues to rely on inefficient metabolic pathways that don’t require oxygen. This produces waste molecules that cause fatigue and force you to slow down. The switch in metabolic pathways is called your metabolic threshold. Athletes strive to increase this threshold in order to increase speed without entering into fatigue. I call that your “sweet spot.” Sound familiar?
So where does plasma nitrite come into the equation? Nitric oxide or supplemental oxygen reduces blood pressure and allows for better blood flow as it dilates veins. When plasma nitrite is in circulation, it targets tissues low in oxygen. This incredible function supplies your muscle tissues with additional oxygen and at a faster rate, meaning your tissues can continue to use the oxygen-dependent metabolic pathways to produce energy, increasing your metabolic threshold. Additionally, because more oxygen is available within muscle tissue, the reliance on inhaled oxygen for energy production is reduced and your VO2 max or aerobic capacity increases. Increasing your metabolic threshold and VO2 max increases your ability to stay aerobic longer at an increased speed.
Beetroot Juice Improves Reaction Time
When you exercise, blood flow to the brain increases by 25 percent through the carotid and cerebral arteries, which supply oxygen-containing blood to the brain. As you increase exercise intensity and oxygenated blood is less abundant, you experience decreased reaction time. We all know staying mentally sharp is essential during exercise, and even more so during competitive events. When plasma nitrite is present, it not only targets muscle tissues low in oxygen, it also targets your brain tissue. Plasma nitrite increases oxygenated blood flow to the brain, which increases reaction time and mental sharpness.
Beetroot Juice Predominately Affects Type II Muscle Fibers
Researchers understand undeniable benefits exist when consuming beetroot juice. So, they are now focusing their studies on which activities produce the most benefit from consumption. Overall researchers conclude plasma nitrite prefers to target type II muscle fibers, which are used primarily during exercise that require fast transitions from low to high intensity or intermittent activity. This is exciting information for athletes because intermittent activity, like interval training, has been shown to increase metabolic threshold and VO2 max, results plasma nitrite also produces. Therefore, although plasma nitrite affects primarily type II muscle fibers acutely, over time one can conclude consumption benefits overall athletic ability, despite the specific activity.
How Much Beetroot Juice Should You Consume and When?
Researchers have shown positive results from consuming 4 to 5 ounces of beetroot juice daily with an additional 4.6-ounce shot 1 hour before exercise. But, the study I found most compelling measured plasma nitrite levels at intervals following consumption of 16.5 ounces beetroot juice. After consumption, plasma nitrite levels continued to rise over the 3-hour testing period, inferring that consuming this amount before exercise will produce the same results. The performance benefits lasted days after consumption of the 16.5 ounces — without additional consumption. With the only known side effect being red stool, it is worth experimenting yourself. And from a dietitian’s point of view, with 16.5 ounces of beetroot juice containing 184 calories and 22.2 grams of simple carbohydrate, this fits perfectly into a 1-hour pre-workout snack for a prolonged event.
Katie Rhodes, owner of OWN-Nutrition, is a registered and licensed dietitian in Little Rock, Arkansas, with a Master of Science in clinical nutrition. Through her experiences training elite athletes and working in the clinical setting at Arkansas Children's Hospital and the Central Arkansas Veterans Association, Rhodes understands that what we are putting in our bodies directly affects our performance, quality of life and longevity. She's worked with triathletes for six years on their nutrition year round as well as focusing on race day nutrition. Rhodes primarily works with clients remotely, through phone calls and Skype for communication, to supplement unique, personalized nutrition plans.
The views expressed in this article are the opinion of the author and not necessarily the practices of USA Triathlon. Before starting any new diet or exercise program, you should check with your physician and/or coach.