Cycle of body mass reduction-recovery, inhibitory control, and performance of judo athletes

• Grant number: 24/08930-1
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2024
• End date: October 31, 2027
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Emerson Franchini
• Grantee: Emerson Franchini
• Host Institution: Escola de Educação Física e Esporte (EEFE). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 24/18847-4 - Cycle of body mass reduction-recovery, inhibitory control, and performance of judo athletes, BP.DR

Abstract

In combat sports, such as judo, athletes compete in different weight categories. This procedure is adopted so that athletes fight opponents with similar physical characteristics. Despite this, athletes frequently engage in rapid weight loss (RWL) to gain an advantage over lighter opponents. Studies evaluating the effect of RWL on performance present controversial results. However, few studies have been conducted after the rule change that altered the weigh-in format, moving the official weigh-in to the day before the competition and a new weigh-in for some athletes (randomly selected) on the morning of the competition. Additionally, studies investigating the effects of RWL on competitive performance have only used the final competition result, disregarding aspects (e.g., technical-tactical aspects) that could affect competitive performance. Therefore, the objective of this study is to evaluate the prevalence, magnitude, and methods related to RWL and its relationship with cognitive and competitive performance. For this purpose, the work is divided into two distinct studies: Study 1 - This study will involve 2,331 athletes from junior and senior categories, of all competitive levels, who have been active for at least one year. To evaluate the prevalence of RWL and the magnitude of weight loss typically experienced by athletes, a rapid weight loss questionnaire (RWLQ), already validated in Brazil, will be used. The questionnaire will be made available for self-completion on the Google Forms online platform. Additionally, athletes at competitions will be contacted and invited to complete the questionnaire. Descriptive analyses (mean, standard deviation, and frequency) will be calculated for all variables. To compare the scores obtained on the questionnaire by the athletes, the Mann-Whitney U test and one-way analysis of variance will be used; Study 2 - The final sample size will be determined after conducting a pilot plan with 8 state-level athletes, of both sexes, adults; those with these characteristics will be used in the final study. After the agreement and characterization of the volunteers, they will be evaluated in the following situations: in a condition without RWL (10 days before the competition), athletes will be evaluated regarding self-control, cognitive performance, and will keep a food diary for 3 days. Before (10 days), during (competition week), and after the RWL period (official weigh-in), athletes will be evaluated regarding self-control, cognitive performance, and will keep a food diary for 3 days, in addition to recording body mass at the official weigh-in, on the morning of the competition, and 1 hour before the first match. The athletes' matches will be recorded throughout the competition for subsequent temporal and technical analyses. The Shapiro-Wilk and Mauchly tests will be used to test the normality and sphericity of the data, respectively. Descriptive analysis will be performed using absolute values (kg) and percentages, with calculations of means, standard deviations, and 95% confidence intervals. Two-factor analysis of variance (group - medalists and non-medalists - and moments) with repeated measures on the second factor will be used to compare the reduction and recovery of body mass between moments, as well as cognitive task performance among athletes with different results. To verify if there is a correlation between the magnitude of body mass recovery and explanatory performance variables, Pearson's correlation test will be used. Logistic regression will be used to determine the association between winning the competition and the adoption of RWL methods. Cohen's effect size (d) and partial eta squared will be reported for all tests when appropriate. The significance level adopted for all analyses will be 5%. (AU)