The effect of beet juice-based foods on the performance of athletes in cyclic sports

BACKGROUND: Modern data from the scientific literature indicate that nitrate, when added to food, can serve as a precursor of nitric oxide (NO). According to research results, the concentrations of nitrates and nitrites in plasma increase when subjects are taking dietary supplements containing nitrates. Such an increase not only contributes to training performance by activating the nitrate pathway of energy supply to muscle activity but also generally improves physical performance.

AIMS: To evaluate the effect of consumption of beet juice, as a source of nitrates, on the performance of biathletes-sprinters.

MATERIALS AND METHODS: Forty male biathletes aged from 18 to 22 years took part in the study. The study took place in a training camp in the summer of 2017. The athletes were divided into an experimental group and a control group. The experimental group was given a preparation containing beet juice of a special variety twice daily after each training session, and the athletes of the control group did not consume anything after training sessions. Before the experiment and after 20 days of intervention, load testing before work refusal was carried out, as well as biochemical and general blood analysis.

RESULTS: In the athletes of the experimental group, who were consuming beet juice, there was a decrease in oxygen uptake per kilogram of body weight and an increase in heart rate at the moment of anaerobic threshold, as well as an increase in load time, which indicates an increase in endurance during anaerobic exercise. This parameter is one of the limiting factors of performance in cyclic sports. In addition, increases in blood iron content, transferrin saturation, hemoglobin concentration, and average erythrocyte volume were observed in participants who consumed the beet juice preparation.

CONCLUSIONS: The observed changes in indicators of the oxygen-transport system of the blood may be one of the mechanisms through which exogenous nitrates realize their positive effect on performance in the anaerobic phase.