Relative age: implications on anthropometric characteristics and motor performance of young soccer players

Author(s)

Juliana Melo Altimari

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Educação Física
• Defense date: 2014-02-25

Examining board members

Antonio Carlos de Moraes; Ezequiel Moreira Gonçalves; Miguel de Arruda; Claudinei Ferreira dos Santos; Charles Ricardo Lopes

• Advisor: Antonio Carlos de Moraes

Abstract

This study examined the effect of relative age (ERA) on anthropometric characteristics and motor performance of young soccer players. To this end, two studies were conducted. In the study, a sample composed of 400 soccer players (15.4 ± 0.4 years) of the U-15 category who participated in the 10th World Cup Football Brazil U-15. Dates of birth and anthropometric measures body mass (BM) and height (H) were obtained from data reported by the teams on the registration form for each athlete to the event organization and CBF. The second study sample was composed of 146 soccer players in the categories U-13 (n = 50, 13.6 ± 0.3 years), U-15 (n = 50, 15.5 ± 0.4 years) and U-17 (n = 46, 17.7 ± 0.3 years). The subjects were submitted to different experimental situations across the board: 1) anthropometric measurements BM, H, lean mass (LM) and fat percent (BF%), 2) assessment of bone age (BA) and 3) motor tests to evaluate aerobic endurance (AE), speed (S10 m and S30 m), lower limb strength from vertical jump (VJ, VJCWUL and VJ SVCAUL), repeated sprint ability (RSA) and fatigue index obtained from the RSA test (FIRSA). In both studies the players were separated according to the categorization of chronological age by four, quarter 1? (1? QT ), young people born between January and April; quarter 2? (2? QT), young people born between May and August and 3? quarter (3? QT), young people born between September and December. For statistical treatment nonparametric chi-square (X2) analysis of variance (ANOVA) two-way, followed by posthoc Scheffé test were used. Correlations between parameters were established by Pearson's correlation coefficient. The significance level for all analyzes was 5%. The results of the first study show a greater number of players born in the first months of the year (1? QT > 2? QT > 3? QT, P<0.05). Likewise, we found significantly higher values for the variables BM and H players born in the first months of the year (1? QT > 2? QT > 3? QT, P< 0.05). In the second study, it was observed that the BM, H and RSA variables showed significant differences between the 1? QT and 3? QT in categories U-13 and U-15 (P<0.05). While for the variable LM significant differences were found between 1? QT and 3? QT category U- 13 (P<0.05). On the other hand, no significant difference for the variables BF%, VJ, VJCWUL, VJ SVCAUL, AE, S10 m, S30 m and IFRSA me between 1? QT, 2? QT and 3? were observed in every category analyzed (P>0.05). It is noteworthy that the values of BM, H and RSA LM, VJ, VJCWUL, VJ SVCAUL, AE, RSA, S10 m, S30 m, variables were significantly different between the players of the category U-13 and U-17 in different quarters (P< 0.05). It was also found that the players of U-13 category had significantly lower height, body mass and lean mass in relation to the category of players U-15 and U-17 in different quarters (P< 0.05). Observed in the three categories analyzed, the prevalence of players showing normal state of maturity in each four (U-13 = 72.0 %, U-15 = 78.0 %, U- 17 = 95.0 %). The findings of the first study suggest that the ERA influences the selection of young Brazilian elite players and that this effect is associated with anthropometric characteristics height and body mass. Corroborating these findings, the results of the second study indicate influence of ERA in categories U-13 and U-15 for the variables body mass, height and repeated sprint ability, while for muscle mass this variable occurred only in the U-13, allowing players born in 1? QDT (Jan-Apr) of these categories advantages compared to those born at 3? QDT (Sep-Dec) (AU)

• FAPESP's process: 10/09143-0 - RELATIONSHIP BETWEEN THE DISTRIBUTION OF MONTH OF BIRTH, MATURATIONAL AGE NEUROMUSCULAR FATIGUE AND MOTOR PERFORMANCE IN YOUNG SOCCER PLAYERS
• Grantee: Juliana Melo Altimari
• Support Opportunities: Scholarships in Brazil - Doctorate