Can elite athletes benefit from nitrate supplementation?
By Kristin Jonvik PhD
Dietary nitrate supplementation, most often in form of beetroot juice, is used by many athletes to enhance sports performance, including elite athletes. Even though beetroot juice is mentioned as one of the top-5 supplements to enhance exercise performance, its ergogenic potential still remains to be fully established. Due to several studies showing a blunted effect of beetroot juice in more highly trained endurance athletes, there is an ongoing discussion whether and to what extent elite athletes can benefit from dietary nitrate supplementation.
On September 13th 2018 Kristin Jonvik a Performance Nutritionist from TeamNL defended her Ph.D. thesis «Dietary Nitrate and Sports Performance» at Maastricht University, the Netherlands. The main goal of this project was to gain further insight into how nitrate (or beetroot juice) supplementation can be used to enhance sports performance, under which conditions, and in which athletes. One of the focus areas of this thesis was to investigate whether elite athletes can benefit from nitrate supplementation, in order to develop sport-specific guidelines for the use of nitrate that can readily be implemented in a practical (top)sport setting.
The beneficial effects of nitrate are related to its ability to increase the bioavailability of nitric oxide (NO), particularly in environments of low oxygen availability and low pH. NO regulates several physiological processes associated with exercise such as blood flow and muscle contraction. Since high-intensity exercise creates an environment of low oxygen availability and low pH, it has recently been suggested that nitrate supplementation could be particularly beneficial for intermittent and repeated-sprint exercises, such as in team sports and sports of high intensity and short duration. Interestingly, the suggested blunted performance effect of nitrate in highly trained compared to recreational athletes has only been described for endurance athletes (Porcelli et al., 2015), and this Ph.D. thesis is the first to investigate the effects of nitrate for elite athletes of other disciplines.
In view of the suggestions that nitrate supplementation may be more effective for recreational athletes and during high-intensity exercise, in one of the studies Jonvik et al (2018) compared the metabolic and functional responses to beetroot juice between recreational, competitive and elite athletes, completing the exact same repeated-sprint exercise protocol (i.e., repeated Wingate tests). Interestingly, the plasma nitrate and nitrite concentrations at baseline and following beetroot juice supplementation were actually very similar between athletes with these different training levels. This is in stark contrast to previous suggestions that elite (endurance) athletes might have higher baseline plasma nitrate and nitrite concentrations and/or an attenuated plasma response to nitrate supplementation. Furthermore, beetroot juice was shown to improve the time to reach peak power, which could be relevant to athletes of various sports where a quick acceleration is important, such as high-intensity field sports and sprint disciplines. And again, there were no differences in the responsiveness between recreational, competitive, and elite athletes, indicating that even elite athletes of high-intensity and/or sprint disciplines could benefit from beetroot juice supplementation.
Other conclusions that can be drawn from this thesis are:
- Nitrate-rich vegetables can effectively be used as dietary nitrate supplements and may actually be more effective than so-called nitrate salts.
- The daily habitual vegetable and nitrate intake is in most athletes far below what is considered an effective supplementation dose of nitrate, and certainly does not explain why highly trained athletes may benefit less from nitrate supplementation.
- Highly trained endurance athletes do not seem to benefit from nitrate supplementation, while there is a potential beneficial effect of nitrate supplementation even in elite athletes under extreme oxygen deprived exercise conditions, such as during very high-intensity and sprint disciplines.
Based on the available literature including the work presented in this thesis, the following recommendations can be made, bearing in mind that there are still several questions to be answered before reaching a definite consensus on how nitrate supplementation can best be used to induce its proposed ergogenic effects.
- Dose: A supplement of ~600-800 mg of nitrate per day on top of a normal diet should be used.
- Duration: A minimum of 5 days of supplementation should be applied.
- Timing: To optimize benefits, beetroot juice should be ingested 2-3 h prior to the event and nitrate-rich vegetables a minimum of 3 h prior to the event.
- Source: A vegetable source is preferred over nitrate salts, taken as a supplement (e.g. 1.5-2 shots of concentrated beetroot juice) or through ~300-400 g nitrate-rich vegetables per day. When such large vegetable intakes are not practically feasible, a beetroot juice shot or other concentrated form of nitrate may be preferred, especially right before competition.
- Type of athletes: For less trained athletes, nitrate is likely beneficial for both endurance and more high-intensity and sprint disciplines. For elite athletes, benefits may only be expected during very high-intensity and sprint disciplines or at altitude and under water, when oxygen is the limiting factor.
The entire Ph.D. thesis is available here
Contact information: Kristin.jonvik@han.nl
References
Porcelli S, Ramaglia M, Bellistri G, Pavei G, Pugliese L, Montorsi M, Rasica L, Marzorati M. Aerobic fitness affects the exercise performance responses to nitrate supplementation. Med Sci Sports Exerc. 2015 Aug;47(8):1643-51.
Jonvik KL, Nyakayiru J, Van Dijk JW, Maase K, Ballak SB, Senden JMG, Van Loon LJC, Verdijk LB. Repeated-sprint performance and plasma responses following beetroot juice supplementation do not differ between recreational, competitive and elite sprint athletes. Eur J Sport Sci. 2018 May;18(4):524-533.
