Conference Paper

The role of relative age and biological age on talent selection in Swiss youth soccer

  • Swiss Federal Institute of Sport Magglingen SFISM and Swiss Swimming Federation
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Introduction In youth soccer, the chronological age is used to group and select the athletes for training and competition. Within these age groups, individuals can differ by as much as 1 year in relative age, which might affect the talent selection process and benefit the athletes born early in the year. Moreover, the biological age varying by 4 years among athletes of the same age group further challenges the homogeneity of training and competition groups (R Malina, Coelho e Silva, & Figueiredo, 2012). The aim of the study was to investigate the effect of relative and biological age on the coaches` performance rating and the talent selection process for the national U15 team members. Methods Within a three year period 185 players (age 14.0 ± 0.3) were recruited from the U15 Swiss national selection days. Players were grouped by birth quarter (Q1: Jan. to Mar.; Q4: Oct. to Dec.) for relative age. The players DXA hand scan (skeletal age) and the Tanner-Whitehouse 3 classification was used to determine the biological age, as an indicator for maturity. Players were classified as early, on time and late developed (R Malina, et al., 2012).Odds ratios (ORs) and 95% confidence intervals (CI) were calculated for birth quarters (relative age) and biological age. Secondly, the effects of relative and biological age were analyzed on the coaches’ subjective performance rating evaluated technical skills, game intelligence, personality, and playing speed. Results The average skeletal age of the soccer players was 14.1 ± 1.5 years, and did not differ significantly from chronological age. Early maturing players born in Q1 were 4.6 times (95% CI 1.7, 12.0) more likely to be selected for the national team than early matures born in Q4. Late maturing players born in Q1 in turn showed higher ORs (17.9 (95% CI 2.4, 135.0)) than their counterparts born in Q4. The coaches’ subjective performance rating showed significantly higher rating in playing speed (3.5 ± 0.5) for early matures than on time (3.2 ± 0.6) and late matures (2.8 ± 0.4). However regarding technical skills and game intelligence, late maturing players (3.7 ± 0.5; 3.6 ± 0.5) were rated significantly higher than early matures (3.3 ± 0.6; 3.3 ± 0.5, respectively). Discussion & Conclusion In conclusion, there is an overrepresentation of players with high relative age (born in Q1) that are selected for the national team. Players born late in the year (Q4) need to be early or on time developed to be selected. Players of Q4 with late maturity might have been deselected in previous selection levels. Secondly, the analysis showed that the coaches` subjective performance rating is highly affected by the maturity. Athletes with early maturity are more likely to have good ratings regarding playing speed, while late developed athletes will have high ratings regarding their technical skills and game intelligence. References Malina, R., Bouchard, C., & Bar-Or, O. (2004). Growth, maturation, and physical activity (2nd ed.). Champaign: Human Kinetics. Malina, R., Coelho e Silva, M., & Figueiredo, M. (2012). Growth and maturity status of youth soccer players. In A. M. Williams (Ed.), Science and Soccer: Developing elite players (3rd ed.). London: Routledge. Contact

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Objective: To investigate the association of relative skeletal age and other risk factors with injury in elite schoolboy footballers (soccer players). Design: Prospective cohort study, with players participating for varying numbers of years. Setting: Manchester United Football Club Academy, 2001 to 2007. Participants: Players were recruited to the club by scouts. At intake, the boys were medically screened to ensure they could be fully involved in the training and games program. Computerized medical records for the boys were maintained for the entire study period. The investigation included boys 9 to 16 years of age. Numbers varied between 98 and 144 per year (mean n/y = 130) over 6 years. Overall, 292 players were represented in the sample. Mean drop out per season was 21%. Assessment of risk factors: Each year consenting players had a radiograph of the left wrist and hand for the assessment of skeletal age (SA), using the Fels method. Eighty-five players had at least 1 radiograph and 12 players had 6 radiographs, 1 in each year of the study. Early and late maturers were those with an SA >1 year older or younger, respectively, than their chronologic age (CA). Information on demographics, height and weight, playing and training times, and position played was collected. Main outcome measures: The main outcome measure was the relation of maturity status to the occurrence of injuries. Main results: For the total sample across all the age groups the incidence of injuries was 1.44 per 1000 hours of training (n = 244 injuries), and 10.5 per 1000 match hours (n = 169 injuries). The mean number of injuries per season was 79.3, with a mean loss of 12.5 injury days per player per season. Boys aged <14 years were most vulnerable. Most injuries resulted from overuse rather than from trauma. Most common injury type and location were, respectively, soft tissue and knee joint. Mean SA for the total sample was in advance of mean CA (12.08y vs 11.74y; P < 0.05). Injury incidence did not differ significantly among late, normal, and early maturing players (1.4, 1.5, and 1.8, respectively) when training time, playing time, height, and playing position were statistically controlled as covariates (P = 0.73). However, results of general log linear analysis of mean data over the 6 seasons indicated a relationship between injury occurrence and training time, match-play time, and the CA-SA difference (P < 0.05). The 3 variables together explained 48% of the variance in injury incidence. Position played, foot dominance, and mean height gain were not related to injury occurrence. Conclusions: Maturity status and time spent in match play and training were significant predictors of injuries in 9- to 16-year-old elite male soccer players.