by Katie Mark
Lettuce begin our workout at a higher beet. I’m not just talking about the new Beyoncé song, but the beetroot that comes from the beet plant. Beet it with the juicing cleanses, and juice up your water with beetroot (BR) juice.
The beetroot and dietary nitrates
The beetroot vegetable is the taproot part of a beet plant. It is a rich source of dietary inorganic nitrates that serve as the active ingredient to the health benefits. Once consumed, the nitrates mix with bacteria in our saliva to be converted into nitrites. Traveling to the stomach, some of the nitrite converts to nitric oxide (NO). The nitrite that is not converted is then circulated and stored in our blood. Nitrites can convert to NO during low oxygen availability, which usually occurs during exercise in skeletal muscle.
NO is a commonly occurring compound in the body, and BR juice adds to these levels. NO dilates blood vessels and improves blood flow to lower blood pressure.
What are the purported benefits of beetroot juice?
Scientists have exercised their love of beetroot juice in various experiments. In numerous small studies containing mostly men and high-level athletes, those consuming BR juice experienced slightly enhanced performance.
Benefits of BR juice include:
- Lowering blood pressure
- Enhancing exercise capacity, in certain situations
- Lowering the amount of O2 your muscles need for submaximal and maximal exercise
- Delaying the decline in cognitive function
- Fighting inflammation
- Providing nutrients and fiber
Beetroot juice and sport performance: What the science says
BR juice acts as an ergogenic aid, which is any substance that enhances athletic performance. Due to the production of NO, BR juice reduces the oxygen cost of exercise, lowers blood pressure, and keeps an athlete focused during exercise. Let’s take a look at some studies.
A double-blind, placebo-controlled, crossover study published in the Journal of Applied Physiology used eight healthy men to evaluate the effects of BR juice on blood pressure and the oxygen cost of exercise. The men had 500 ml/day of BR juice or placebo for 6 consecutive days. Moderate- and high-intensity exercise tests were completed on the final 3 days. They found that systolic blood pressured decreased by about 8 mmHg. The time to exhaustion increased by 16% with BR juice supplementation.
A double-blind, randomized, crossover study recently published in the European Journal of Applied Physiology used 16 male athletes (rugby, hockey and football players) to drink BR juice for 7 days. On day 7, all participants completed an intermittent sprint test. They were also given cognitive tasks designed to test how accurately and how fast they made decisions. Each participant completed these tasks after taking a nitrate-rich beetroot juice shot (400 mg of nitrates per shot) and a placebo version with the nitrate removed. Researchers found that the nitrate-rich version saw an improvement in both sprint performance (3.5%) and speed of making decisions (3%) without negatively affecting decision accuracy.
Another double-blind, randomized crossover study explored BR juice and its effects on muscle efficiency and intense intermittent (stop and go) exercise. Fourteen male athletes drank 490 mL of nitrate-rich BR juice and nitrate-depleted placebo juice over 30 hours before an intermittent recovery test. Performance was 4.2% better with BR juice. The nitrite concentration decreased by 20% with the placebo compared to 54% with the BR juice. The researchers suggested that nitrate supplementation could promote nitric oxide production and improve performance, which may be due to muscles being able to take up more glucose or better maintenance of exciting muscles during contraction.
Limitations: These results demonstrate tiny improvements in people who are already trained. However, these small improvements may actually be important for competitive athletes for which a few minutes can make or break winning a race or beating their own time on a time trial. Preventing the decline in decision-making is important for team sports like soccer and football. Continue on to evaluate if you’re an athlete who could benefit from BR juice.
Are you an athlete who could benefit from BR juice?
Just because you’re an athlete or you workout everyday doesn’t mean that BR juice is the drink for you. Intensity and duration of the sport as well as the fitness of the athlete is critical to evaluating whether or not it is ergogenic for the athlete.
Nitrates could affect athletes who do more stop and go exercise (i.e., sprints, high-intensity interval training, etc.) seen in team sports. Those who are endurance athletes may not benefit as much. Yet, the effect of BR juice on prolonged endurance exercise has not been studied as much.
Also, in low-intensity endurance exercise, the muscles are usually sufficiently oxygenated that there is little need for nitric oxide to help increase blood flow and oxygenate our muscles more.
Deets on Beets
The range of nitrate intake for the health benefits is 300-600 mL. For instance, Beet-It makes concentrated BR juice in 70 mL shots, which is about 300 mL of beet juice. The concentration is to help avoid digestive problems that may arise. Some athletes use around 500 mL of BR, or two shots. However, a higher intake of nitrates does not translate to better sport performance.
An acute (2-3 hours before exercise) or a short-term (at least 3 days) protocol can be used. Short-term strategies can help the performance of high-intensity exercise (taken a few days before). Acute supplementation and sport performance lacks consistent results because of differences in health, diet, age, fitness and sport of the athlete. However, it can still be taken 2-3 hours before exercise.
- Red stool and urine. The carotene in beets give it that beautiful color, but as the carotenes travel through the gut unabsorbed they may end up adding a red hue to the stool and urine. This discoloration is harmless. Just be prepared!
- Upset stomach, diarrhea, and nausea. Some people may experience upset stomach, diarrhea and nausea. This is why BR juice manufacturers concentrate their shots of BR juice.
- Dietary oxalates. It is suggested that those with kidney stones should avoid BR juice because it contains oxalates. If you currently have or have a history of kidney stones then speak to a registered dietitian. There’s a bit of conflicting research on which foods increase formation of kidney stones in at-risk people.
Beetroot juice or the entire beetroot: Does it matter?
The roots of the beetroot are usually eaten boiled, roasted or raw. They can either be eaten alone or with any salad vegetable.
Research from the Journal of the Academy of Nutrition and Dietetics investigated if eating beetroot could improve endurance exercise performance in 11 fit men and women. All participants ate baked beetroot (200 g containing >500 mg nitrate) before a 5-km time trial on a treadmill. In a separate trial, each participant had cranberry relish (as the placebo) before the time trial. The study found that the average running speed was faster after eating beetroot. There was a 5% increase in speed during the last 1.1 miles of the run. It was concluded that eating beetroot ~60 minutes before exercise may improve running performance in healthy adults.
If you decide to take BR juice powder, be sure to follow the manufacturer’s directions, especially the timing. Most powders require intake ~30-60 minutes before exercise since they’re concentrated shots. One-teaspoon of BR powder is about three beets.
Beetroot juice is promising
BR juice demonstrates that there’s a performance benefit from eating vegetables. These benefits may usher in either a few days leading up to exercise (if you’re “nitrate loading”) or 2-3 hours before exercise (acute supplementation). BR juice lowers blood pressure and may improve sprint performance and mitigate the decline in decision-making that can occur in some sports. Whole BRs are a good alternative to concentrated “shots” of BR juice (if you’re trying to save money or want to take advantage of beets in your recipes).
The great thing about BR juice is that it doesn’t come in a man-made pill to help sport performance. It’s actually food. So try a BR juice shot before your next intense training session or competition. With BR juice, you can’t beet unleashing the power of food.
Katie Mark is a second year MS/MPH student and avid road cyclist. She will ride 100 miles for the Best Buddies Challenge in May and 185 miles over two days for the Pan-Mass Challenge in August. She will take shots of beetroot juice before both rides.