Efeito da idade relativa e de variáveis somatomotoras na seleção de jovens atletas de futebol

Abstract

This document aimed to identify objective factors related to the selection or not of new athletes, as a way to subsidize future evaluations, based mainly on physical, anthropometric and relative age aspects. Data collection took place through the registration forms of the athletes. The outcome was approval status in the selection test, and the exposure variables were: relative age, divided into quartiles, according to month of birth; height, measured in centimeters; maximum sprint speed, measured in a 20 m linear sprint test (S20); and jump height (in centimeters), measured using the Jump Countermovement. The sample consisted of 363 adolescents, enrolled in the club's selection in the year 2022 and divided into four age categories: under-11, under-13, under-15, under-17. Descriptive statistics were applied to the data, using mean and 95% confidence intervals (95% CI), considering height variables and physical performance measures. To compare the proportion of approved by birth quartile, the chi-square test was performed. Logistic regression was used to test the association between approval status and birth quartile. To assess height and physical performance measurements according to approval status, a T-Test was performed. All analyzes were stratified by category. The significance level was 5%. Of the total number of athletes who participated in the selection, most were registered for the under-13 category. In general, the S20 average was 3.41 seconds (95% CI 3.38-3.45), the average jump was 27.88 cm (95% CI 27.22-28.54), while the mean height was 165.80 cm (95% CI 164.50-167.10). Ninety-five teenagers passed the training club selection. When grouping under 11 and under-13 categories, athletes born in the first quartile had 5.37 times more chance of being approved (95%CI 1.35-21.41; p=0.017) than those born in the last quartile. Regarding the performance variables, for the sub-15 category, the sprint average was 3.31 s (95% CI 3.22-3.40) among approved and 3.44 s (95% CI 3, 38-3.50) among those who did not pass (p=0.023). As for the sub-17 category, the time spent was 3.09 s (95% CI 3.02-3.16) among those approved and 3.22 s (95% CI 3.17-3.26) among not approved (p=0.024). With regard to jumping, for the under-13 category, the mean was 24.62 cm (95% CI 22.61-26.62) and 22.37 cm (95% CI 21.17-23.57) for approved and not approved (p=0.044), while for the under-17 category, it was 34.09 cm (95% CI 31.47-36.71) and 30.27 cm (95% CI 29, 17-31.36) (p=0.010), respectively.