Beetroot is becoming increasingly popular as a performance enhancer for athletes and those looking to gain a competitive advantage in running and cycling.
Some people juice beetroot, some eat it whole, and still others powder it and make a drink – but does it make a noticeable difference to how fast you can run a race or cycle up a hill?
Small gains for some
A large systematic review conducted in 2020 included 80 clinical trials in which participants were randomly assigned to drink beetroot juice or not, and found that drinking beetroot juice improves athletic performance.
In a sport where every second and centimetre counts, this can be a huge improvement: in a 16.1 kilometre (10 mile) cycling time trial, the improvement associated with beetroot consumption was equivalent to 48 seconds.
However, when the authors analysed subgroups of these studies, they found that beetroot juice had no effect on women or elite athletes, although this may be because there were too few participants in these groups to draw any conclusions.
Another large systematic review in 2021 of 73 studies in endurance athletes (long-distance running, swimming, or cycling) found similar results: beetroot (and other nitrate-rich vegetables) supplementation reduced time to exhaustion by an average of 25.3 seconds and distance traveled by 163 meters.
The improvements were seen in recreational athletes but not in elite athletes or sedentary people, and the analysis did not look specifically at women.
What is beetroot?
Beetroot is rich in nitrates and anthocyanins, both of which have health benefits, but it is the nitrates that primarily have a positive effect on performance.
Once ingested, nitrates are converted to nitrites by local bacteria in the mouth, and in the acidic conditions of the stomach, nitrites are converted to nitric oxide, which is absorbed into the bloodstream.
Nitric oxide dilates blood vessels and delivers oxygen to muscles more quickly, so they can provide more energy to burn during exercise.
As a result, less energy is used to perform and it takes longer to tire.
How can I use beetroot juice?
The Australian Institute of Sport (AIS) has assessed beetroot and categorised it as a Group A supplement, meaning there is strong scientific evidence for its use in certain sporting situations.
The AIS advises that beetroot supplements are beneficial for exercise of between four and 30 minutes, training, competitive events and team sports involving intermittent exercise.
For performance reasons, AIS recommends that beetroot products (juice, powder or food) contain 350-600mg inorganic nitrates. Check the label. There are several concentrated juices on the market.
Beetroot contains around 250mg of nitrates per 100g, so you would need to consume at least 200g of roasted beetroot to get the same effect.
The product should be taken 2-3 hours before training or competition to allow time for the nitrates to be converted into nitric oxide and absorbed into the bloodstream. Additional benefits may be seen if you drink beetroot juice a few days before training or competition.
However, avoid using antibacterial products like mouthwash, chewing gum, or candy, as these kill the bacteria in your mouth that are needed to convert nitrates to nitrites.
Are there any drawbacks?
Your urine may turn red, making it harder to tell if you are dehydrated, and your stool may also turn red.
Beetroot juice can cause stomach upset for some people, so try drinking it during training to see if it causes any problems – the last thing you want to discover is this on competition day.
What about the nitrates you get from the rest of your diet?
While it’s difficult to get enough nitrates directly from vegetables before a competition to enhance athletic performance, eating five servings of vegetables a day can help keep nitric oxide levels high in the blood.
Vegetables high in nitrates include celery, arugula, spinach, endive, leeks, parsley, kohlrabi, Chinese cabbage, and celery. There is no clear evidence on the effect of cooking or storing them on nitrate levels, so it’s probably best to eat them the way you most like.
However, you should avoid cured meats with added nitrates: The additives are used to inhibit bacterial growth and add flavor and color, but the resulting sodium nitrite may increase your risk of cancer.
Beetroot may give you a small performance boost, but remember to adjust the rest of your training too – make sure you’re getting enough carbohydrates and protein and drinking plenty of water – you may need to consult with an exercise scientist and a licensed practicing sports nutritionist for best results.
Evangeline Mantsiouris, Program Director of Nutrition and Food Sciences, University of South Australia, Registered Dietitian
This article is republished from The Conversation under a Creative Commons license. Read the original article.
An earlier version of this article was published in February 2023.
