There is a growing number of sports for which the performance-enhancing effects of beetroot juice have been proven, but the latest study concerns a sport that is a little less mainstream. Researchers from the Western Australian Institute of Sport and the Australian Institute of Sport in Canberra are the first to document the ergogenic effects of beetroot juice supplementation in national and international level kayakers.
Their study, which is soon to be published in the International Journal of Sport Nutrition and Exercise Metabolism, involved two different experiments. The first part took 6 national level male kayakers and gave them placebo (i.e. beetroot juice with the nitrate removed) or beetroot juice containing 4.8 mmol of nitrate (i.e. 297.6mg) 2.5 hours prior to a battery of laboratory-based session on a kayak ergometer. Interestingly, this dose did not produce any significant performance benefits, however, subjects receiving the beetroot did consume significantly less oxygen than the placebo group.
The second part of the study took 5 international level female athletes and gave them double the dose of nitrate that subjects received in the first study (i.e. 9.6 mmol or 595mg of nitrate). This time the testing was performed on-water and consisted of two 500m time trials. Moreover, kayakers took the beetroot juice or placebo 2 hours prior to testing as opposed to 2.5 hours for the first study. Subjects receiving the beetroot juice improved their performance on average by 1.7%. While this may not sound like much, at international level, it can be the difference between getting on the podium and an also-ran.
The most fascinating aspect of this study concerns the contrasting effects of increased dosage on performance. This trend has been observed in a number of other studies involving beetroot supplementation and suggests that dose is a very important aspect of beetroot juice supplementation if one wants to maximise performance benefits. It also highlights the importance of standardised nitrate content in any beetroot supplement. While many supplements on the market contain ‘beetroot extract’ very few actually specify the amount of nitrate, which invariably means they are not standardised extracts.
Peeling P, et al. Beetroot juice improves on-water 500m time-trial performance, and laboratory-based paddling economy in national and international-level kayak athletes. International Journal of Sport Nutrition and Exercise Metabolism. 2014 Sep 8. [Epub ahead of print]