Beetroot Juice - Legal Doping for Athletes?

Nitric oxide (NO) is a physiologically important signaling molecule that promotes the expansion of blood vessels and thus facilitates the transport of oxygen (O 2 ) and energy substrates to the muscles. Research shows that nitric oxide (NO) also improves the effectiveness of mitochondrial respiration, which is manifested by reduced oxygen consumption during exercise. Until recently, it was thought that nitric oxide (NO) could only be formed as a result of the endogenous pathway of oxidative transformations L-arginine. Recent research results indicate, however, that an alternative to the endogenous pathway of nitric oxide (NO) formation may be the exogenous supply of inorganic nitrates (NO 3 – ) with food. The aim of the study was to review the current literature on the properties of beetroot juice as an important source of nitrates (NO 3 – ) and its effectiveness in improving the exercise capacity of physically active people. A systematic review of the research, published from 2005 to January 31, 2021, was made on the basis of searching bibliographic databases such as: PubMed, Elsevier and Web of Science. The following keywords were used: “beetroot”, “beetroot juice”, “nitrates”, “nitrites”, “nitric oxide”, “supplementation”, “ergogenic substances”, “sports nutrition”. Although there are conflicting data, it appears that beetroot juice supply may be a cheap, natural, and promising nutritional strategy for improving sports performance in both endurance and intermittent high intensity (start-stop) exercise. More detailed studies are analyzing the effect of dietary nitrate (NO 3 – ) supply in anaerobic exercise – especially in high-volume resistance training – are needed. It is also emphasized that further research is needed to elucidate the effects of specific factors on the variability of ergogenic effects after beetroot juice consumption, which may be of the greatest importance in terms of the effectiveness of this nutritional intervention. In a crossover double-blind the beetroot 5.5 mmol/NO in the to from (NO 3 – according to a list provided. On the last days of the experiment, the were subjected to exercise testing. Based on the results, the supply of nitrate (NO 3 – ) with beetroot resulted in an increase in nitrite (NO 2 – ) concentration, a decrease in systolic blood well as an improvement in muscle oxygenation indices and a decrease in VO 2max . The of this 3 could potentially during prolonged weightlifting. A meta-analysis conducted by San Juan, Dominguez, Lago-Rodriguez, Montoya, Tan, Bailey (2020), on nitrate (NO 3 ) supply along with beetroot juice on improving muscle strength, contraction velocity and muscular endurance during weightlifting, showed that beetroot juice supply may be a promising nutritional intervention in improving contraction velocity and the ability of athletes to perform more repetitions during weightlifting, however, it was emphasized that further research is needed in this area. – Studies on the effect of beetroot juice consumption on the production of N-nitroso compounds (NOCs), and thus analyzing its consumption in relation to the risk of cancer, are limited. In a randomized controlled trial, the aim of which was to analyze the endogenous formation of N-nitroso compounds after consumption of beetroot juice and the effect of vitamin C supplementation on the excretion of the above-mentioned. compounds with urine, it was shown that in 29 healthy adults, recreationally active, consumption of concentrated beetroot juice in a dose of 70 ml (400 mg (NO 3 – ) caused a significant increase in the level of N-nitroso compounds (NOCs) in the urine, measured as ATNC (Apparent Total Nitrosamine Content) after one day and in the next seven days. Based on the data obtained, it was found that vitamin C supplementation was able to inhibit the excretion of N-nitrosamine compounds (NOCs) after consuming one dose of beetroot juice, but not for a longer period. The authors of the study concluded that caution should be exercised with long-term use of beetroot juice as an intervention to support exercise capacity, and signaled the need for more extensive research to rule out possible long-term adverse health effects