TOOLBOX: Athletes are often looking for any competitive edge they can get – whether that is lighter & stiffer bike components, more effective training programs, or even their diets & supplements. In past articles, we have investigated the positive benefits of caffeine on performance. However, in this month’s Toolbox article, I want to focus on another common supplement for endurance athletes: beetroot juice!
Why Beetroot?
You might be wondering how something like beets could possibly help you ride your bike faster. In fact, many people find the taste of beets too ‘earthy’ and dislike a common side-effect of oddly-colored urine. However, beetroot is high in inorganic nitrates, which can be reduced to nitrites by bacteria in our mouths. Nitrites are further processed into Nitric Oxide (NO) by our guts. NO is a powerful signaling molecule which causes vasodilation – the widening of our blood vessels – as well as increasing blood flow & mitochondrial respiration. As you might expect, these effects make ATP energy production in the mitochondria more efficient for sub-maximal efforts. Given these positive effects on the cardiovascular system, beetroot juice has commonly been recommended as an ergogenic aid for endurance cyclists, runners, & triathletes.
The Pros
According to the research, the primary benefit of supplementing with foods high in inorganic nitrates, like beetroot, is an increase in submaximal exercise efficiency. In other words, you can either decrease the amount of oxygen required at a particular power/speed (known as VO2) or slightly increase your power/speed without increasing your VO2.
Aside from the aforementioned specific performance benefits, foods high in inorganic nitrates – leafy greens like spinach, arugula, & beetroot – are great for general health too. In fact, they are known to decrease blood pressure, reduce inflammation, & improve cardiovascular health.
The Cons – Timing, Dosing, & Quantity
Unfortunately, simply eating some beets for dinner tonight won’t be enough for you to reap all the benefits for your training. In fact, most peer-reviewed studies feature at least a 1 week ‘wash-in’ period, where the body gets accustomed to the supplementation. Generally speaking, to best capitalize on the positive benefits of beetroots, you will need consistent, large doses at frequent intervals.
So, how much beetroot is needed to reap the claimed benefits? While there isn’t a number set in stone, many athletes will aim for 400 – 800 mg/day, which is a considerable amount. Raw beets typically contain approximately 250 mg of nitrates per 100 g consumed. Rather than eating solid beets, many athletes choose to mix them into smoothies (or drink them straight). However, there are also options for pre-mixed beetroot juice (like ‘Beet it’ sport shots), and powdered beetroot supplements. That being said, many powdered supplements don’t contain as many inorganic nitrates as you’d hope – be sure to check the nutrient information!
If you decide to read more into various peer-reviewed studies, you will notice very specific timing for participants, since it takes time for the body to convert inorganic nitrates into potent Nitric Oxide concentrations. Further, researchers also know that NO levels can only stay peaked for a short period of time. In most studies, researchers will provide beetroot juice approximately two hours before their exercise intervention.
Interaction with Other Supplements
Lastly, it’s important to consider the interaction of other supplements (like caffeine) along with beetroot juice. Researchers have proposed that the positive effects of beetroot juice might possibly be undermined by caffeine. If you’ve had good success supplementing your training with a morning coffee, you might consider sticking with caffeine. Researchers have also found that chewing gum & mouthwash also wash out the positive effects of beetroot juice, suggesting that these mouthwashes & gums interfere with the helpful bacteria that help reduce inorganic nitrates.
Is Beetroot Juice Supplementation For You?
You should always consult your doctor before taking any new supplements. While the benefits of beetroot juice are well documented in the scientific literature, what works for others may not work for you. Beetroot juice has been shown many times to effectively increase your aerobic capacity, those benefits do require some additional consideration from you regarding the dose & timing of supplementation. There seems to be some anecdotal evidence on various cycling forums regarding the effectiveness of beetroot juice, but whether it works for you or not could be a fun experiment for you to test out. That’s all for this month – stay safe, ride fast, and I’ll see you next month!
References
Domínguez R, Cuenca E, Maté-Muñoz JL, García-Fernández P, Serra-Paya N, Estevan MC, Herreros PV, Garnacho-Castaño MV. Effects of Beetroot Juice Supplementation on Cardiorespiratory Endurance in Athletes. A Systematic Review. Nutrients. 2017 Jan 6;9(1):43. doi: 10.3390/nu9010043. PMID: 28067808; PMCID: PMC5295087.