The effect of beetroot juice supplementation on blood nitrate levels, sport performance, and cognitive function in adult soccer players: a double-blinded crossover randomized controlled trial.

The effect of beetroot juice supplementation on blood nitrate levels, sport performance, and cognitive function in adult soccer players

A controlled, double-blind, randomized, phase 2 clinical trial with crossover groups on 20 athletes. In this crossover study, subjects were distributed between two intervention and placebo groups in phase 1, and after a one-week washout period, subjects were switched between the two groups. For randomization in this study, a lottery method was used as a simple randomization method.

This study will be done in a covered sports hall. First, participants will be asked to go to the hall after 12 hours of fasting. Five mL blood samples will be collected from each participant. Moreover, demographic information and data on clinical history, physical activity, and a 24-h dietary recall will be gathered. After blood sampling, participants will consume a standard breakfast. Thirty min after breakfast, participants will receive either 140 mL beetroot juice (BRJ) containing 800 mg nitrate (2*70 mL) or natural BRJ without added nitrate. 150 min after BRJ intake, blood sampling will be repeated. After that, sport performance tests will be performed. All participants and outcome assessors will be blinded.

Inclusion criteria • Football athletes aged 18 to 22 years Exclusion criteria • Sensitivity to nitrate-rich beetroot juice and its compounds

10 female athletes and 10 male athletes each receive 140 ml of nitrate-rich beetroot juice or normal beetroot juice during exercise sessions (totally 2 sessions for each group). . They will receive the supplement and in the next session they will change places.

Aerobic capacity, maximum vertical jump, 30 m speed, cognitive function, blood nitrate level.

In this study, simple randomization will be used to distribute individuals and the randomization unit will be individuals. This randomization will be done in a stratified manner so that 20 soccer players will be placed in two strata, male and female (stratified randomization). 10 people will be included in each stratum. The randomization tool in this study will be sealed envelopes so that each person in each stratum will be given a specific code and these codes will be placed in sealed envelopes and then the individuals will be distributed into two groups using a lottery. Given that all participants in this study will be known in advance and will be present on the day of sampling, a person unaware of the study objectives will distribute the sealed envelopes into the two groups (allocation concealment). Therefore, due to the simple randomization method in this study, there is no need to create a random sequence.

This study is a double-blind clinical trial. The nitrate-rich beet juice and normal beet juice will be packed identically in terms of (color, shape and smell) in similar 140 cc bottles. Patients, researchers who are responsible for sampling and evaluating tests and statistical analyzes will be blinded.