Effects of beetroot juice supplementation on performance during aerobic exercise: a brief review

The search for nutritional supplements that can enhance performance is a constant among those involved in high-performance sports. Beetroot juice, rich in inorganic nitrate (NO3-), promote an increase in the plasma concentration of nitric oxide (NO), an important signal in several physiological processes that would justify the ergogenic effects on athletic performance. Thus, the aim of this review was to evaluate and synthesize the available evidence on the possible effects of beetroot juice supplementation on aerobic performance. A search was performed in the Pubmed and Portal Capes databases, using descriptors in English and Portuguese. After application of inclusion and exclusion criteria, 13 studies were included in the quantitative synthesis. Apparent controversy was observed regarding the effects of beetroot juice on performance. The main reasons for the apparent inconsistency seem to be related to the different intervention methodologies and the heterogeneity of the evaluated groups. Therefore, it was not possible to establish references about the positive effects of supplementation, even though this has been shown by some studies, which also showed improvements in different physiological mechanisms induced by the greater bioavailability of NO. However, in high-performance sports, differences that would be apparently insignificant can be decisive, thus justifying the study of individual response and the possible use of supplementation.