Does action variability predicts performance between elite karate athletes?

• Grant number: 25/27063-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2026
• End date: November 30, 2026
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Emerson Franchini
• Grantee: Pedro Gonçalves Negri
• Host Institution: Escola de Educação Física e Esporte (EEFE). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In karate kumite, varying the stimuli offered to the opponent may be important for performance. In addition, the emergence of video review may have generated changes in the relationship between effort time (E) and pause time (P) during matches. The male <75 kg and female <61 kg categories at the Premier League Cairo 2025 will be analyzed. Actions involving feints or strikes will be recorded and detailed with respect to the limb used, target, technique, timing, score, stance, and context. The outcomes of the actions, matches, and the tournament' result will be considered to measure performance. Twenty matches will be analyzed in duplicate. Only variables that reach an ICC greater than 0.75 and a Kappa coefficient greater than 0.81 will be included in the final analysis. The Shapiro-Wilk and Mauchly tests will be used to assess data normality and sphericity, respectively, with Greenhouse-Geisser correction applied if necessary. Data will be reported as absolute and percentage values, with 95% confidence intervals, and as means and standard deviations or medians and interquartile ranges. Sexes will be compared using Student's t-tests for independent samples or Mann-Whitney tests. A two-way analysis of variance (competition phase and match outcome) with repeated measures will be used to compare performance in the competition and the outcome of a given match. The Bonferroni test will be used as a post-hoc procedure. Partial eta squared will be used as an indicator of effect size. The significance level will be set at 5%.