Measuring optimal psychological states: Proposal of two brief versions to measure flow and clutch in athletes.

Background: The study of sports experiences with high levels of performance has led to the observation of two psychological states categorized as optimal, denominated flow and clutch. The objective of this study is to design and validate two brief scales version to measure flow and clutch.

Methods: Following the MIMO (Maximum Information, Minimum Discomfort) protocol, three studies are carried out: In Study 1, we developed the short versions of the questionnaires based on theory-driven and data-driven criteria; in Study 2, we used quantitative criteria to validate the short versions; and in Study 3, we checked the final version of each scale to observe their statistical validity and their relation to other variables.