Abstract

Introduction: There are strategies aimed at improving the performance of athletes, some of which establish recommendations regarding hydration and fluid replacement, with the purpose of ensuring an adequate water balance at all stages of sports practice. However, there is a lack of adequate and reliable instruments to explore this issue.Objective: The present research aims to validate the content and evaluate the reliability of the instrument Knowledge, attitude and behavior regarding hy-dration and fluid replacement among adolescent and young adult athletes in Chile. Methods: The cultural adaptation was carried out through the Delphi method with a panel of experts in the area. For the evaluation of reliability, the questionnaire was applied online to a sample of 384 athletes from different disciplines on two occasions to determine temporal stability.Results: All items achieved percentages of agreement higher than 80% according to Aiken's V statistic, in relation to relia-bility a Cronbach's Alpha of 0.78 was obtained, which shows an acceptable internal consistency, additionally an intraclass Correlation Coefficient of 0.64 was obtained between the two applications of the questionnaire presenting a regular to good reliability. Conclusion: This questionnaire can be used as a reliable tool for future research around sports nutrition, as well as an instrument that contributes to the work of different professionals to support the planning and evaluation of strategies aimed at improving sports performance.