The relative age effect in under-17, under-20, and adult elite female soccer players.

To investigate the RAE in elite female soccer players, the absolute and relative birthdate distributions of players who disputed the Women's World Cup were assessed. Differences between observed and expected distributions were analyzed using chi-square and effect sizes. The birthdates of 1224 female soccer players were assessed in Under-17 (N = 336), Under-20 (N = 336) and adult (N = 552) categories. There was no significant RAE in adult category for different playing positions and players in general (including all playing positions per age category). There was significant RAE for midfielders and players in general with mainly small effect sizes for the U-17 and U-20. In both age categories, players born in Q1 were over-represented with the highest quartile ratio for midfielders. In regard of RAE and success defined by final ranking at the World Cup, we found no significant differences between the birthdate distributions of players who participated in either the group stages or finally the knockout phases. Coaches should consider this information to avoid bias in talent programs designed to promote and select female soccer players independently of their birthdates. Young female players should be encouraged to learn to play in different field positions before to reach high-level performance.

Correlations between jump measures and competitive performance remain stable over time in top-level sprinters.

BACKGROUND: We examined the relationships between jump performance measures, sprint tests, and 100-m competition times in 11 top-level sprinters during two successive competitive 4-week mesocycles. METHODS: Physical tests were performed 7-12 days before 3 sequential competitions. Sprinters completed standing long jump, squat and countermovement jumps, and 60-m sprint tests on each occasion. A repeated measures analysis of variance was used to compare the physical assessments and actual competition results among the three moments. A Pearson product-moment correlation coefficient was used to analyze the relationships between the multiple variables over the consecutive mesocycles. Significance level was set at P<0.05. RESULTS: No significant differences were observed among the periods for any jump or sprint performance measure (ES ranging from 0.02 to 0.33; P>0.05). Very large to nearly perfect correlations were observed for all sprint and jump variables and 100-m dash times in the three moments analyzed (P<0.05). CONCLUSIONS: Our data indicate that simple jump measures can be prospectively used to monitor sprint performance. Notably, the standing long jump test was the most consistently related to 100-m time. This simple strategy may help track and field coaches to better adjust the competitive approach of their sprinters, thus optimizing their peak performance.

Centesimal Age and Relative Age Effect in Elite Futsal Players.

To investigate centesimal age (CA) and relative age effect (RAE) in elite male futsal players their date of birth and court-position were accessed through the official FIFA website. The absolute and relative frequency distributions of player births were quantified by quartiles and semesters. The two-way ANOVA and the Chi-Square analysis were applied to check for possible differences. The results showed a mean CA of 27.76 ± 4.11 years with no differences for both playing positions and competitions. In addition, no significant differences were found between quartiles or between semesters. The results suggest that elite male futsal athletes reach optimal competitive performance close to 27 years. Neither playing position nor geographical location may affect RAE, which seems to not affect the competitive performance (ranking) of elite male futsal players. These findings may help practitioners to understand the RAE phenomenon in futsal. In conclusion, being born in the early months of the year appears not to be important to successful performances in futsal. Overall, futsal athletes take about two decades to achieve their best performance. Coaches and researchers should consider the implementation of long-term training strategies (≈ 20 years) to progressively and effectively develop young futsal players.