title: Stability of elite freestyle performance from childhood to adulthood.
abstract: Stability of athletic performance is important for practitioners and coaches, since it allows the selection of appropriate training methods and prediction of ages for best results. We performed a longitudinal study of 1694 season-best performances of 242 elite-standard swimmers throughout their careers, from 12 to 18 years of age. Mean stability (descriptive statistics and one-way repeated-measures ANOVA, followed by a Bonferroni post-hoc test) and normative stability (Cohen's kappa tracking index and the Pearson correlation coefficient) were determined for seven consecutive seasons. Performance improvements in all events were observed (14.36-18.97%). Bonferroni post-hoc tests verified changes in almost all events assessed. Cohen's kappa demonstrated low stability (0.17-0.27) in relative performance. Pearson correlations only became high from 15 to 16 years in the 50-m and 100-m events, and from 16 to 17 years in the 200-m, 400-m, and 1500-m events. Our results show that: (a) swimmers should display a substantial improvement (14-19%) to become elite standard as adults, such as at 18 years; (b) 16 is the age at which the ability to predict adult performance increases markedly.
authors.affiliation: Department of Sport Sciences, Polytechnic Institute of Bragança, Bragança, Portugal. mariojoc@hotmail.com
authors.forename: Mário J
authors.initials: MJ
authors.lastname: Costa
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Marinho
authors.forename: José A
authors.initials: JA
authors.lastname: Bragada
authors.forename: António J
authors.initials: AJ
authors.lastname: Silva
authors.forename: Tiago M
authors.initials: TM
authors.lastname: Barbosa
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000704:Analysis of Variance; D056352:Athletes; D054874:Athletic Performance; D002648:Child; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010806:Physical Education and Training; D012189:Retrospective Studies; D013550:Swimming