Relative Age Effect in Elite Swimmers in U14 Czech Championship

Abstract

PURPOSE The issue of the Relative Age Effect (RAE) has been studied in the theory of sports for more than 30 years. Most studies concentrate on team sports, while the area of some individual sports like swimming can be considered still underexplored. METHODS The aim of our study was to verify the RAE in young elite swimmers (n = 198) who participated in Czech Republic U14 Championship (1) in male and female samples (2) according to swimming disciplines and distances (3) and performance (times in individual disciplines) between individual quartiles / semesters of birth. The analysis was performed with the use of adequate statistical (chi-square test, Kruskal-Wallis H test, Mann-Whitney U test) and effect size (effect size w index, eta-square test, effect size r index) tests.RESULTS The results showed a different intensity of RAE sex-differences (male: w = 0.033; female: w = 0.006). In the division by the swimming disciplines and swimming distances, statistically significant values with large effect size were found in males in 50 m freestyle, 200 m individual medley, 100 m butterfly and 200 m butterfly. However, this did not apply for girls. Analysis of differences in performance showed a significant difference between the dependent variables (sex, distance, discipline) by different independent variables of quartile / semester of birth with large effect size only in cases of male 100 m breaststroke and female 200 m individual medley.CONCLUSIONS The issue of RAE should be circulated among the coaches working with youth, athletes, sports organizations, but also parents of athletes in order to avoid the termination of actively spent time or drop-outs.

The Relative Age Effect at Different Age Periods in Soccer: A Meta-Analysis

“…We checked publication bias using the Funnel plot, The Egger’s Regression-Based test, Effect size Estimates for Trim-and-Fill Analysis, and Fail-safe N . The Funnel plot, suggesting a publication bias, is available in Supplementary Figure 1 (Bozděch et al, 2023a). Subsequent funnel plots of subgroups (age period) further showed that publication bias was significantly smaller for soccer players who were older than 19 years of age and slightly lower for 15–19-year-old players.…”

“…The supplementary materials (Bozděch et al, 2023b) encompassed independent results obtained from the studies we researched. These materials included information about the age category, performance level, sex, sample size, and calculated effect size estimation ( w , OR Q1 vs. Q4, OR Q2 versus Q4 , OR Q3 versus.…”

“…More precisely for the variables Q 1 versus Q 4 , Q 2 versus Q 4 , Q 3 versus Q 4 , and S 1 versus S 2 , if one of the cells (observed value) fore OR estimation equaled 0, the Haldane-Anscombe correction was used (Anscombe, 1956; Haldane, 1956); that is, we added .5 to all cells of the 2 × 2 table. An overview of individual results is available in supplementary materials (Bozděch et al, 2023b).…”

Relative age effect at Czech elite swimmers in U12 category

“…Předložená studie navazuje na naši předchozí práci, kde jsme se zaměřovali na mladé elitní plavce (chlapce a dívky) ve věkové kategorii U14 (Bozděch, Agricola, Křehký, Schlegel, & Zháněl, 2022). Co se týče zjištěných rozdílů mezi jednotlivými studiemi (tzn.…”

Maturity Status and Relative Age of Elite Taekwondo Youth Competitors—Case Study on Croatian National Team

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