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Bezuglov E, Malyakin G, Emanov A, Malyshev G, Shoshorina M, Savin E, Lazarev A, Morgans R. Are Late-Born Young Soccer Players Less Mature Than Their Early-Born Peers, Although No Differences in Physical and Technical Performance Are Evident? Sports (Basel) 2023; 11:179. [PMID: 37755856 PMCID: PMC10536659 DOI: 10.3390/sports11090179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 09/28/2023] Open
Abstract
The aim of the study was to compare the status of somatic maturity, anthropometry, strength, speed, and soccer-specific technical skills of players from leading youth soccer academies born in different quarters of the same calendar year. A total of 678 young male soccer players from eight leading Russian soccer academies took part in the study. The following anthropometric measures and physical characteristics were measured: height, weight, body mass index, countermovement jumps (CMJ), 5, 10, and 20 m sprints, speed dribbling, foot and body ball juggling, and short and long pass accuracy. The determination of somatic maturity as a percentage of projected adult height was collected. All subject dates of birth were divided into four quartiles according to the month of birth. The analysis of all data obtained was conducted both within the total sample and by quartiles of birth, according to the age group categories of 12-13 years, 14-15 years, and 16-17 years and the degree of somatic maturity. There was a widespread relative age effect, with 43.5% of early-born players and only 9.6% of late-born players representing the sample. Early-born players were more mature than late-born players (p < 0.001 and p < 0.001) but had no statistically significant differences in strength, speed, or soccer-specific skills.
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Affiliation(s)
- Eduard Bezuglov
- Department of Sports Medicine and Medical Rehabilitation, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (E.B.); (M.S.)
- High Performance Sports Laboratory, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Georgiy Malyakin
- Department of Sports Medicine and Medical Rehabilitation, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (E.B.); (M.S.)
- High Performance Sports Laboratory, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Anton Emanov
- High Performance Sports Laboratory, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Grigory Malyshev
- High Performance Sports Laboratory, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Maria Shoshorina
- Department of Sports Medicine and Medical Rehabilitation, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (E.B.); (M.S.)
| | - Evgeny Savin
- High Performance Sports Laboratory, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Artemii Lazarev
- Department of Internal Medicine, Mount Sinai Hospital, Chicago, IL 60608, USA;
| | - Ryland Morgans
- Department of Sports Medicine and Medical Rehabilitation, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (E.B.); (M.S.)
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Bezuglov E, Morgans R, Butovskiy M, Emanov A, Shagiakhmetova L, Pirmakhanov B, Waśkiewicz Z, Lazarev A. The relative age effect is widespread among European adult professional soccer players but does not affect their market value. PLoS One 2023; 18:e0283390. [PMID: 36952464 PMCID: PMC10035832 DOI: 10.1371/journal.pone.0283390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 03/08/2023] [Indexed: 03/25/2023] Open
Abstract
BACKGROUND The relative age effect (RAE) is most prevalent in highly competitive youth soccer and persists to a lesser extent in senior soccer. However, it is known that soccer players born in the second half of the year are as successful at senior level, indicating that they are equally talented although under-represented at youth level due to bias during the selection process, in which the emphasis is on more pronounced physical qualities in a specific period of time. Examining the prevalence of the RAE among professional soccer players depending on the level of competition and playing position, as well as analyzing the relationship between the player's birth quarter and market value, are of scientific interest. METHODS The dates of birth, playing position, and market value of all adult male soccer players included in the final rosters of teams from the top-division of 54 European countries, listed on www.transfermarkt.com on August 15th, 2020, were analyzed (18,429 soccer players in total). All players were categorized into four groups according to the quarter of birth (Q) and playing position. All teams were further sub-divided in groups depending on the soccer clubs' level of representation in the UEFA Champions League. RESULTS Of 18,429 players, 30.9% were born in Q1, 25.7% in Q2, 23.8% in Q3 and 19.6% in Q4. The number of soccer players born in Q1 was lower in less competitive leagues. The number of players born in Q1 decreased as the level of competition decreased; the highest percentage of these players was observed in clubs that are among the top 50 ranked in UEFA or compete in the most prestigious European championships. The RAE was less pronounced in teams that participate in lower competitive championships. There was no significant difference in market value between players playing position and level of competition when born in different quarters. Although, the most expensive soccer players in the European championships were late-born forwards. Players of various groups differed in their market value. CONCLUSIONS The RAE is currently prevalent in all the most competitive senior soccer leagues and teams in Europe regardless of playing position. There are no significant differences in market value between players of the same playing position and level of competition when born in different quarters. The most expensive soccer players in the European championships are forwards born in Q4. These findings may indicate that the under-representation of "late-born" soccer players in youth, and then consequently in adult soccer, is not associated with lower talent, but with other factors, possibly based on physiological characteristics and socio-cultural factors. Further measures are needed to mitigate the discriminatory effects of selection bias based on the RAE.
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Affiliation(s)
- Eduard Bezuglov
- Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
- High Performance Sports Laboratory, Moscow Witte University, Moscow, Russian Federation
- Academy of Talents, Moscow, Russian Federation
| | - Ryland Morgans
- Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
| | | | - Anton Emanov
- Academy of Talents, Moscow, Russian Federation
- Smart Recovery Sports Medicine Clinic, Moscow, Russian Federation
| | | | - Bekzhan Pirmakhanov
- Faculty of Medicine and Health Care, Department of Epidemiology, Biostatistics and Evidence-Based Medicine, Al-Farabi Kazakh National University, Almaty, Kazakhstan
- FC Kairat, Almaty, Kazakhstan
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Ruscello B, Morganti G, Apollaro G, Saponara A, Esposito M, Marcelli L, Filetti C, Porta M, Grossi A, Pantanella L. Relative age effect in Italian soccer: a cultural issue in talent management? J Sports Med Phys Fitness 2023; 63:136-143. [PMID: 35437304 DOI: 10.23736/s0022-4707.22.13663-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND Relative age effect (RAE) is a well-known phenomenon among those involved in youth sports, especially when the sport being investigated is widespread and involves early selection for participation in national and international competitions. METHODS The purpose of this study was to verify whether the Italian youth soccer ecosystem has adapted to this issue over the years, comparing players born in 1995 and in 2005 and been playing in Under 16 teams in the appropriate years. The sample included 13 professional Italian soccer teams. The number of players analysed was 260 (1995) and 344 boys (2005), respectively, making a total of 604 players enrolled in this study. RESULTS Relative age effects were detected by χ2 goodness of fit tests both in players born in 1995 (P<0.000;V=0.40) and in 2005 (P<0.0001;V=0.39). χ2 test of independence showed no significant difference between the two groups of players (P=0.986;V=0.02), confirming a substantial parity of the phenomenon over the two investigated birth years. CONCLUSIONS Ten years of research and dissemination of RAE did not change the selection policies adopted by coaches and/or scouts, who favor relatively older players during the selection processes. Therefore, RAE appears as the result of the Talent Identification and Development Structures, characterized by early selection and early specialization, and which consider performance as the pre-requisite for gaining access to the next developmental stages. Sport organizations should be aware of this issue and counteract accordingly, since it is important to mitigate the presence of RAE, as it causes inequality of opportunity.
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Affiliation(s)
- Bruno Ruscello
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy - .,School of Sports and Exercise Sciences, San Raffaele University, Rome, Italy - .,Department of Industrial Engineering, Faculty of Engineering, Tor Vergata University, Rome, Italy - .,LUISS SportLab, LUISS University, Rome, Italy -
| | - Gabriele Morganti
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
| | - Gennaro Apollaro
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
| | - Antonio Saponara
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
| | - Mario Esposito
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
| | - Lorenzo Marcelli
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy.,Department of Industrial Engineering, Faculty of Engineering, Tor Vergata University, Rome, Italy
| | | | - Marco Porta
- School of Sports and Exercise Sciences, San Raffaele University, Rome, Italy
| | - Alberto Grossi
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
| | - Laura Pantanella
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
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Maturation Selection Biases and Relative Age Effect in Italian Soccer Players of Different Levels. BIOLOGY 2022; 11:biology11111559. [PMID: 36358260 PMCID: PMC9687510 DOI: 10.3390/biology11111559] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/21/2022] [Accepted: 10/22/2022] [Indexed: 11/06/2022]
Abstract
Simple Summary Soccer academies and societies research young players who are supposed to possess great motor skills. In association with these, adolescents who appear to be talented exhibit more developed anthropometric and body composition features than untalented players. Although many selected soccer players appear to present an earlier maturation than their contemporaries, it is not clear whether soccer teams of different competition levels are aware of this aspect and considered these discrepancies in the scouting selection process. In addition, it remains unclear if the biological maturity and relative effect are two interchangeable methods of evaluation and if one of them deserves to be preferred by the soccer scouters. This research aims to investigate the effect of the team level, maturity status and relative-age effect, and their interactions, on body characteristics, cellularity, and physical performance in adolescent soccer players. Despite the relative age effect remaining the easier analysis to consider, the evaluation of maturity status seems to be the most reliable method to detect better capabilities due to early growth. Abstract Soccer is a sport practiced all over the world, in which players are expected to show specific physical and technical skills. Soccer academies look for young talented individuals to develop promising players. Although several parameters could affect the players’ performance, the relative age effect (RAE) and the maturity status appeared debated. Therefore, this study compared the differences in RAE and biological maturity among the players of two Italian soccer teams of different levels and to understand their interaction effects with the competition level on youth players’ physical characteristics and abilities. One hundred and sixty-two young soccer players from the U12 to U15 age categories of the elite (n = 98) and non-elite (n = 64) teams were recruited. The prevalence of maturity status and RAE was observed. Many anthropometric parameters, BIA vectors, and motor tests (CMJ, Sprint, RSA) were carried out. The maturity status had a greater effect on several anthropometric characteristics and on 15 m sprint, while it affected the CMJ only in U12 (F = 6.187, p ≤ 0.01). Differently, the RAE seemed to priorly affect the U13 and U15 categories in body composition, whereas its effect appeared on the 15-m sprint (F(3, 45) = 4.147, p ≤ 0.01) and the RSA (F(3, 45) = 3.179, p ≤ 0.05) in the U14 category. In addition, early matured players or those who were born in the first six months presented cellular characteristics similar to adult elite players. Soccer professionals should be encouraged to monitor the maturity status to better interpret changes in the physical performance of young soccer players to guide adequate training plans.
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Jia H, Wan B, Bu T, Luo Y, Ma W, Huang S, Gang L, Deng W, Liu Z. Chinese physical fitness standard for campus football players: A pilot study of 765 children aged 9 to 11. Front Physiol 2022; 13:1023910. [PMID: 36277178 PMCID: PMC9581199 DOI: 10.3389/fphys.2022.1023910] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 09/20/2022] [Indexed: 08/23/2023] Open
Abstract
Objectives: In 2022, 55 million Chinese children participate in campus football; however, there is no physical fitness standard, making it a priority task to enhance the current national program. This study aimed to explore a pilot method for the development of a reliable physical fitness standard. Methods: This study examined 765 male football players aged 9 to 11 in 2020 and 2022. The anthropometric and physical fitness assessments were conducted in accordance with the Chinese Football Association's field manuel. Physical fitness tests include sit and reach test, t test, 30 m run test, and vertical jump test. Physical fitness standard was modeled using the generalized additive models for location, scale, and shape (GAMLSS). Data were fitted with appropriate GAMLSS distributions and smoothing term. P-splines were applied to smooth the model's parameters using the default local maximum likelihood method and link functions. Following diagnostics of fitted models, age-specific centile estimations were computed for physical fitness tests. In addition, players in each age group were categorized according to their body mass index as normal weight or overweight/obese. Welch's t-test was utilized to compare the group differences in physical fitness testing. The significance level was chosen at p < 0.05. Results: Sit and reach test, t test, 30 m run test, and vertical jump test data were fitted with original Sinh-Arcsinh, Box-Cox power exponential, Box-Cox power exponential, and Box-Cox Cole and Green, respectively. Physical fitness standard for each age group is presented as tabulated centiles (1p, 3p, 5p, 15p, 25p, 50p, 75p, 85p, 95p, 97p, 99p). Overweight/obese campus football players did significantly worse (p < 0.05) on the t test, 30 m run test, and vertical jump test than their normal-weight peers of the same age. Conclusion: This study developed the first physical fitness standard for 9 to 11-year-old campus football players in China. We made three recommendations to Chinese policymakers on sample size, data management, and field procedure for the creation of a national physical fitness standard.
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Affiliation(s)
- Hong Jia
- College of Physical Education, Hunan Normal University, Changsha, China
| | - Bin Wan
- College of Physical Education, Hunan Normal University, Changsha, China
| | - Te Bu
- College of Physical Education, Hunan Normal University, Changsha, China
| | - Yang Luo
- Hunan Kuying Sports Development Co Ltd, Changsha, China
| | - Weiping Ma
- College of Physical Education, Hunan Normal University, Changsha, China
| | - Sen Huang
- Hunan Institute of Sport Science, Changsha, China
| | - Liang Gang
- Hunan Biological Electromechanical Vocational Technical College, Changsha, China
| | - Wei Deng
- School of Foreign Language and Culture, Guangdong University of Finance, Guangzhou, China
| | - Zeyong Liu
- College of Physical Education, Hunan Normal University, Changsha, China
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Pedersen AV, Aune TK, Dalen T, Lorås H. Variations in the relative age effect with age and sex, and over time-Elite-level data from international soccer world cups. PLoS One 2022; 17:e0264813. [PMID: 35482636 PMCID: PMC9049515 DOI: 10.1371/journal.pone.0264813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 02/17/2022] [Indexed: 11/18/2022] Open
Abstract
The relative age effect (RAE) is a statistical bias observed across sport contexts and consists of a systematic skewness in birth date distribution within an annual-age cohort. In soccer, January 1st is the common cut-off date when categorizing players in competitions according to their chronological age, which potentially disadvantages those within the cohort who were born later in the year. Thus, relatively older soccer players in their cohort can be favored in talent identification, selection, and development. The aim of the current study was to investigate the variations in RAE in male and female international youth world-cup tournaments (U17 and U20) in the period from 1997-2019 and in international senior world-cup-tournaments from 2006-2019. A total of 20,401 soccer players participating in 47 different tournaments were analyzed. The birthdate distributions were categorized into four quartiles (January-March, Q1; April-June, Q2; July-September, Q3; October-December, Q4) and compared to a uniform distribution using Chi-square analysis with Cramer's V (Vc) as a measure of effect size. Based on the existing data concerning RAE in elite junior and senior soccer, it was hypothesized that: (I) the RAE is present in youth soccer world cup tournaments but is stronger in male players than in female players; (II) the younger the soccer players, the stronger the RAE; and (III) the RAE in world cup soccer tournaments has strengthened over time. All these hypotheses were supported by the data; novel findings included that the effect has now entered women's soccer, and in men's soccer it persists into senior world cup tournaments. Thus, a strong RAE bias occurs in selection among elite soccer players competing in international world cup tournaments.
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Affiliation(s)
- Arve Vorland Pedersen
- Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU, Trondheim, Norway
| | - Tore Kristian Aune
- Department of Sports Science, Faculty of Education and Arts, Nord University, Levanger, Norway
| | - Terje Dalen
- Department of Sports Science, Faculty of Education and Arts, Nord University, Levanger, Norway
| | - Håvard Lorås
- Department of Teacher Education, Faculty of Social and Educational Sciences, NTNU, Trondheim, Norway
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Gimunová M, Sebera M, Bozděch M, Kolářová K, Vodička T, Zvonař M. The Impact of Different Periods of Walking Experience on Kinematic Gait Parameters in Toddlers. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 19:58. [PMID: 35010316 PMCID: PMC8744759 DOI: 10.3390/ijerph19010058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/16/2021] [Accepted: 12/19/2021] [Indexed: 06/14/2023]
Abstract
This study aimed to analyse the kinematic differences in gait between three groups of toddlers who differed in their weeks of independent walking (IW) experience, but not in anthropometrical characteristics, to determine the relationship between walking experience without the side effect of morphological differences on gait parameters. Twenty-six toddlers participated in this study. Depending on the week of their IW, toddlers were divided into three groups: Group 1 (1-5 weeks of IW), Group 2 (6-10 weeks of IW), and Group 3 (11-15 weeks of IW). Each toddler walked barefooted over a 2-m long pathway, and 3D kinematic data were obtained. A decrease in the upper limb position, hip flexion, and step width, i.e., changes towards the adult gait pattern, were observed in Group 3. Less experienced walkers exhibited a wider step width despite no statistically significant difference in body mass and height between groups. Results of this study show no statistically significant difference in step length between groups, suggesting that step length is more related to height than to the walking experience. The increased step length in more experienced walkers reported in previous studies may therefore be a result of different heights and not walking experience.
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Affiliation(s)
- Marta Gimunová
- Department of Kinesiology, Faculty of Sports Studies, Masaryk University, 62500 Brno, Czech Republic; (M.S.); (M.B.); (T.V.); (M.Z.)
| | - Martin Sebera
- Department of Kinesiology, Faculty of Sports Studies, Masaryk University, 62500 Brno, Czech Republic; (M.S.); (M.B.); (T.V.); (M.Z.)
| | - Michal Bozděch
- Department of Kinesiology, Faculty of Sports Studies, Masaryk University, 62500 Brno, Czech Republic; (M.S.); (M.B.); (T.V.); (M.Z.)
| | - Kateřina Kolářová
- University Sport Centre, Faculty of Sports Studies, Masaryk University, 62500 Brno, Czech Republic;
| | - Tomáš Vodička
- Department of Kinesiology, Faculty of Sports Studies, Masaryk University, 62500 Brno, Czech Republic; (M.S.); (M.B.); (T.V.); (M.Z.)
| | - Martin Zvonař
- Department of Kinesiology, Faculty of Sports Studies, Masaryk University, 62500 Brno, Czech Republic; (M.S.); (M.B.); (T.V.); (M.Z.)
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Gil SM, Bidaurrazaga-Letona I, Larruskain J, Esain I, Irazusta J. The relative age effect in young athletes: A countywide analysis of 9-14-year-old participants in all competitive sports. PLoS One 2021; 16:e0254687. [PMID: 34270609 PMCID: PMC8284647 DOI: 10.1371/journal.pone.0254687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 07/02/2021] [Indexed: 11/18/2022] Open
Abstract
The relative age effect (RAE) has primarily been investigated in male athletes involved in popular sports and high-level competitions. However, occurrence of RAE in other types of sports at the grassroots level, particularly in female athletes, is less well-studied. Thus, we examined the RAE in a large cohort of young athletes who participated in all competitive sports in Bizkaia, Spain, according to gender and specificity of the sport. The birth dates of 38,381 participants (65.1% males and 34.9% females) aged 9–14 years old in 37 competitive sports were analyzed. Birth dates were divided into four birth-quarters and compared to those of all children born in the same period using a χ2 goodness-of-fit test and standardized residuals. The effect size Cramer’s V was measured, and odds ratio and 95% confidence intervals were calculated to determine the odds of athletes born in January playing in the highest leagues. In the total sample, in boys RAE was evident in football, but only in higher-competition leagues (p<0.001, large effect size). In girls, RAE was evident in the most popular team sports: basketball (p<0.001, large effect size in basketball 1st league), handball and football (p<0.05, both small effect sizes). Players born in January were 3.23- and 2.89-times more likely to play in the 1st leagues than those born in December, for boys (football) and girls (basketball) respectively. In the overall analysis and in the remaining sports, presence of RAE was negligible. Therefore, the date of birth does not seem to be a constraint to participating in most sports in Bizkaia. The potential mechanisms for RAE are multifactorial and complex, yet a combination of factors, such as the popularity of a sport and the depth of competition, physicality and social influences may be involved. We discuss these mechanisms and potential measures to mitigate RAE.
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Affiliation(s)
- Susana M. Gil
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
- * E-mail:
| | - Iraia Bidaurrazaga-Letona
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | | | - Izaro Esain
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Jon Irazusta
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
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Figueiredo P, Seabra A, Brito M, Galvão M, Brito J. Are Soccer and Futsal Affected by the Relative Age Effect? The Portuguese Football Association Case. Front Psychol 2021; 12:679476. [PMID: 34122274 PMCID: PMC8194498 DOI: 10.3389/fpsyg.2021.679476] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 04/26/2021] [Indexed: 11/18/2022] Open
Abstract
A better understanding of the relative age effect (RAE) in youth will increase the awareness of the need for reducing the bias of (de)selection. Thus, we investigated the RAE in youth female and male soccer and futsal players in Portugal, using nationwide data. Birthdates of 5,306 female and 126,285 male soccer players, and 2,437 female and 23,988 male futsal players (U7–U19), registered in Portugal during the season 2019–2020, and Portuguese National teams (from U15 to AA soccer teams and from U17 to AA futsal teams) were analyzed. Data were categorized into age groups and certification levels [no certification, basic football training center, football school, and training institution] of the respective clubs/academies. Birthdates were stratified from the start of the selection year using quartiles (Q) and semesters (S). Differences between the observed and expected birthdate distributions were analyzed using chi-square statistics, and RAEs were calculated using odds ratios (OR). In both soccer and futsal, female players, in the age category U9, RAEs were found (Q1 vs. Q4, OR: 1.49 and 1.84, respectively). In male soccer, differences in the birthdate distribution were observed in all age categories (U7–U19) with significant OR between all comparisons (Q and S). In contrast, an over-representation of young male futsal players (Q1 vs. Q4) was observed only in the age categories U7 and U9 (OR: 1.54 and 1.34, respectively). The stratification by certification level showed a significant RAE for all certification levels in male soccer players. In contrast, in male futsal players, the RAE was significant only in clubs and academies with the highest level. For National teams, the RAE was more pronounced in male soccer, particularly in the U16 and U17 (OR: 9.84 and 12.36, respectively). Data showed a RAE in female and male youth soccer and futsal, particularly in male, younger age categories, and in clubs and academies having a higher certification level, which could be accompanied by a loss of valuable elite players during the youth phase of their careers. Thus, adjustments in the systems and structure of talent identification are recommended to prevent RAE-related discrimination in youth soccer and futsal.
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Affiliation(s)
- Pedro Figueiredo
- Portugal Football School, Portuguese Football Federation (FPF), Oeiras, Portugal.,Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), University Institute of Maia (ISMAI), Maia, Portugal
| | - André Seabra
- Portugal Football School, Portuguese Football Federation (FPF), Oeiras, Portugal.,Research Centre in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sport, University of Porto, Porto, Portugal
| | - Marta Brito
- Portugal Football School, Portuguese Football Federation (FPF), Oeiras, Portugal
| | - Marta Galvão
- Portugal Football School, Portuguese Football Federation (FPF), Oeiras, Portugal
| | - João Brito
- Portugal Football School, Portuguese Football Federation (FPF), Oeiras, Portugal
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Darwinian Selection Discriminates Young Athletes: the Relative Age Effect in Relation to Sporting Performance. SPORTS MEDICINE-OPEN 2021; 7:16. [PMID: 33650038 PMCID: PMC7921243 DOI: 10.1186/s40798-021-00300-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 01/12/2021] [Indexed: 11/10/2022]
Abstract
BACKGROUND The relative age effect (RAE) is a worldwide phenomenon, allowing sport participation and elite selection to be based on birthdate distribution. Negative consequences include both a narrow, non-optimal elite selection and negative health effects on entire populations. This study investigated the RAE and athletic performance in multiple individual sports in Sweden. METHODS Birthdates of athletes born between the years 1922 and 2015 were collected across 4-month periods (tertiles: T1, T2, T3) from cross-country skiing (N = 136,387), orienteering (N = 41,164), athletics (N = 14,503), alpine skiing (N = 508), E-sports (N = 47,030), and chess (N = 4889). In total, data from 244,560 athletes (women: N = 79,807, men: N = 164,753) was compared to the complete parent population of 5,390,954 births in Sweden during the same years. Chi-squared statistics compared parent and cohort distributions stratified by sport, sex, and age. RESULTS A significantly skewed distribution of birthdates was present in all sports, both sexes, and most age groups. The largest RAEs are seen in children where T1 often constitutes 40-50% and T3, 20-25% of the population. In E-sports, an inversed RAE was seen in adults. In most investigated sports, birthdate distribution was correlated to performance in children but not in adults. CONCLUSIONS Skewed birthdate distributions were consistently prevalent in all investigated individual sports in Sweden, both physically demanding and cognitive/skill-based. As sport participation is related to total level of physical activity, both present and future, failing to address the RAE issue at an early age will result not only in a narrow and arbitrary selection for adult elite athletes but also in a negative impact on public health.
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The Relative Age Effect on Anthropometry, Body Composition, Biological Maturation and Motor Performance in Young Brazilian Soccer Players. J Hum Kinet 2021; 77:147-157. [PMID: 34168700 PMCID: PMC8008302 DOI: 10.2478/hukin-2021-0017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
The present study aimed to investigate the influence of months of birth on anthropometry, body composition, biological maturation, and motor performance in young Brazilian soccer players. Young Brazilian soccer players from the Under-13 (n = 50; 13.6 ± 0.3 years), Under-15 (n = 50; 15.5 ± 0.4 years), and Under-17 categories (n = 46; 17.7 ± 0.3 years) took part in this study. Athletes were divided according to chronological age, 1st tertile (January to April); 2nd tertile (May to August); and 3rd tertile (September to December). Anthropometry, body composition, biological maturation, and motor performance variables were evaluated for all participants. There were no differences between the U-13, U-15, and U-17 categories regarding birth tertiles (p > 0.05). Differences between the ages and birth tertiles were observed for the stature, body mass, and lean body mass (p < 0.05). Moreover, differences were found in maturational status between the ages and birth tertiles (p < 0.05). In general, U-13 players showed lower values compared to U-15 and U-17 players in tests of motor performance. In addition, there was a difference in motor performance between the birth tertiles only for RSA variables. The months of birth influenced the stature, body mass, lean body mass, and repeated sprint ability in the U-13 and U-15 categories. Thus, care should be taken during the process of talent selection, as many young players could be underestimated due to their date of birth.
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Barreira J, Bueno B, Chiminazzo JGC. Relative age effect and age of peak performance: an analysis of women's football players in the Olympic games (1996-2016). MOTRIZ: REVISTA DE EDUCACAO FISICA 2021. [DOI: 10.1590/s1980-65742021006921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
| | - Bruno Bueno
- Universidade Metodista de Piracicaba, Brazil
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Impact of the Relative Age Effect on Competition Performance in Basketball: A Qualitative Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17228596. [PMID: 33228103 PMCID: PMC7699389 DOI: 10.3390/ijerph17228596] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 12/27/2022]
Abstract
Performance in basketball is multifactorial. One of the modifying factors is the “Relative Age Effect—RAE”. However, its impact depends on the sample characteristics and sport context. The purpose of this study was to examine the influence of the RAE on basketball competition performance by analysing peer-reviewed articles published until July 2020. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses systematic search guidelines, nine studies were identified in four databases: Sport Discus, PubMed, Web of Science, and Scopus. Moreover, a study quality analysis using “Strengthening the Reporting of Observational Studies in Epidemiology” guidelines was carried out. The results confirmed an impact of the RAE on competition performance in basketball (56% measurements) and a higher influence of the RAE on short-term collective performance (54% measurements). Statistical parameters were affected, especially in men and U14-U18 categories. No impact of the RAE reversal and no influence of the RAE on long-term collective performance were found. There was a higher impact of the RAE in men (71%), the U14-U18 categories (44%), and at the national level (40%) was identified. The RAE has a variable influence on basketball performance according to developmental constraints. Nevertheless, the findings should be considered based on the sport context due to the heterogeneity and variability of the identified results.
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Reference performance values of pre-seasonal physical fitness in elite youth male football players in Greece. J Public Health (Oxf) 2020. [DOI: 10.1007/s10389-020-01408-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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de la Rubia A, Lorenzo-Calvo J, Lorenzo A. Does the Relative Age Effect Influence Short-Term Performance and Sport Career in Team Sports? A Qualitative Systematic Review. Front Psychol 2020; 11:1947. [PMID: 33071837 PMCID: PMC7538615 DOI: 10.3389/fpsyg.2020.01947] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/14/2020] [Indexed: 11/16/2022] Open
Abstract
Background: The impact on athletes based on grouping methods according to the date of birth within the constituent year, known as the relative effect of age (RAE), is a factor that can influence the achievement of sports success. Many studies have examined the magnitude of this phenomenon in sport; however, the relationship between the RAE and performance in team sports competition has not been accurately evaluated so far. The purpose of this study was to conduct a systematic review on the influence of the RAE on competition performance in team sports through analysis of published peer-reviewed articles from 2000 to 2019. Methods: According to Preferred Reporting Items for Systematic Reviews and Meta-Analysis systematic search guidelines, 19 studies were identified of the 2,093 that were found in the systematic searching process carried out in four databases: Sport Discus, PubMed, Web of Knowledge, and Scopus. The sample of the study was composed by 77,329 players, of which 92.08% were male and 7.92% were female, whereas the recorded performance measurements were 87,556. The relation between relative age effects and competition performance was registered according to constraints-based theoretical model: individual constraints (sample characteristics) and task constraints (sport context). Moreover, study quality analysis, Strengthening the Reporting of Observational Studies in Epidemiology, was carried out. Results: The short-term individual (10.20%) and collective (18.09%) performance was influenced by the RAE, whereas the long-term individual performance (49.71%) was affected by the RAE reverse. However, in 16.99% of the measurements, no relationship was found between the RAE and competition performance. In the analysis by subcategory, the influence of the RAE was higher in men, in adulthood (senior category), in invasion games, and in national contexts. Discussion: The findings clearly demonstrated that the RAE has a great influence on the performance in team sport. Possible implications for policy and practice should be discussed in order to prevent unequal practice based on biased models that prioritize the athlete's current performance and therefore obviate their maturational development. The heterogeneity and variability of the identified results require a relativization of the findings of this study.
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Affiliation(s)
- Alfonso de la Rubia
- Departamento de Deportes de la Facultad de Ciencias de la Actividad Física y del Deporte-INEF de la Universidad Politécnica de Madrid, Madrid, Spain
| | - Jorge Lorenzo-Calvo
- Departamento de Deportes de la Facultad de Ciencias de la Actividad Física y del Deporte-INEF de la Universidad Politécnica de Madrid, Madrid, Spain
| | - Alberto Lorenzo
- Departamento de Deportes de la Facultad de Ciencias de la Actividad Física y del Deporte-INEF de la Universidad Politécnica de Madrid, Madrid, Spain
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Abstract
The concept of the relative age effect refers to the consequences of the physical and psychological differences that may exist between those born earlier or later within the same calendar year. The objective of the present study was to examine this phenomenon in Spanish professional soccer, identifying the influences of the competitive level and the club of origin. The sample comprised 2,130 individuals from five competitive categories: under 12 (U12; n = 480), under 14 (U14; n = 338), under 16 (U16; n = 390), under 19 years old (U19; n = 489) and professional players (n = 433), with nine teams from the Spanish professional soccer league (PSL). Statistical analysis was based on a chi-squared test followed by calculation of the odds ratios and 95% confidence intervals. The main results show that at all levels of competition there was over-representation of individuals born in the first few months of the year. By clubs, the same over-representation was observed. It may be concluded that the relative age effect is consistent and exists throughout Spanish soccer, whether at youth or professional levels. An analysis by age categories showed a more pronounced effect in those competitions in which the youngest players participate, while in clubs the effect continued to be significantly present in all cases investigated in the study.
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Campos FAD, Pellegrinotti ÍL, Campos LCB, Dias TMR, Gómez MÁ. Relative Age Effect in the Girls' Volleyball U18 World Championship. J Hum Kinet 2020; 72:195-202. [PMID: 32269660 PMCID: PMC7126263 DOI: 10.2478/hukin-2019-0106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The relative age effect (RAE), within the sporting scope, refers to the possible advantages of participation and performance of athletes born in the first months of the year of selection in relation to others within the same age category. The aim of the present study was to investigate the RAE in girls' volleyball players participating in the U-18 World Championship, analysing the differences between the medal teams and other teams in the tournament, and considering this phenomenon in relation to the continents. Data collection was obtained from the website of the International Volleyball Federation with a sample made of 1654 youth players in the last six world championships (2007, 2009, 2011, 2013, 2015 and 2017). A greater representation of athletes born in the first months of the year of all the world championships was observed. In the comparison among the continents, it was observed that in Africa, there was a more equal distribution of quartiles compared to America, Asia and Europe. It should be noted that there was a higher percentage of medalist athletes born at the beginning of the year in comparison to the countries that placed in the last three positions of the championship. Therefore, in U-18 female volleyball, there is an advantage to have the closest birth age at the beginning of the competitive biennium.
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Affiliation(s)
- Fábio A. D. Campos
- Federal Institute of Education, Science and Technology Goiano, Ceres, Brazil
| | | | - Leandra C. B. Campos
- Federal Institute of Education, Science and Technology Goiano, Ceres, Brazil
- Methodist University of Piracicaba, Piracicaba, Brazil
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Gil SM, Bidaurrazaga-Letona I, Martin-Garetxana I, Lekue JA, Larruskain J. Does birth date influence career attainment in professional soccer? SCI MED FOOTBALL 2019. [DOI: 10.1080/24733938.2019.1696471] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Susana M Gil
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Iraia Bidaurrazaga-Letona
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Imanol Martin-Garetxana
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
- Medical Services, Athletic Club, Lezama, Spain
| | - Jose A Lekue
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
- Medical Services, Athletic Club, Lezama, Spain
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Kelly AL, Wilson MR, Gough LA, Knapman H, Morgan P, Cole M, Jackson DT, Williams CA. A longitudinal investigation into the relative age effect in an English professional football club: exploring the ‘underdog hypothesis’. SCI MED FOOTBALL 2019. [DOI: 10.1080/24733938.2019.1694169] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Adam L. Kelly
- Faculty of Health, Education and Life Sciences, Birmingham City University, Birmingham, UK
- Children’s Health and Exercise Research Centre, College of Life & Environmental Sciences, University of Exeter, Exeter, UK
- Exeter City Football Club, Exeter, Devon, UK
| | - Mark R. Wilson
- Children’s Health and Exercise Research Centre, College of Life & Environmental Sciences, University of Exeter, Exeter, UK
- Exeter City Football Club, Exeter, Devon, UK
| | - Lewis A. Gough
- Faculty of Health, Education and Life Sciences, Birmingham City University, Birmingham, UK
| | | | - Paul Morgan
- Children’s Health and Exercise Research Centre, College of Life & Environmental Sciences, University of Exeter, Exeter, UK
- Exeter City Football Club, Exeter, Devon, UK
- The College of Life & Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Matthew Cole
- Faculty of Health, Education and Life Sciences, Birmingham City University, Birmingham, UK
| | - Daniel T. Jackson
- Faculty of Health, Education and Life Sciences, Birmingham City University, Birmingham, UK
| | - Craig A. Williams
- Children’s Health and Exercise Research Centre, College of Life & Environmental Sciences, University of Exeter, Exeter, UK
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Reeves MJ, McRobert AP, Lewis CJ, Roberts SJ. A case study of the use of verbal reports for talent identification purposes in soccer: A Messi affair! PLoS One 2019; 14:e0225033. [PMID: 31714943 PMCID: PMC6850519 DOI: 10.1371/journal.pone.0225033] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 10/28/2019] [Indexed: 11/19/2022] Open
Abstract
Using a two-study approach, the main purpose of this case study was to explore the use of a verbal reporting methodology to better understand the thought processes of soccer talent scouts during an in-situ talent identification environment. Study 1 developed a standardized coding-scheme to examine verbal cognitions during a single soccer game. Study 2 then utilized this methodology to examine two full-time recruitment staff trained in the use of concurrent verbal reporting before undertaking a live, in-game task. Participants also participated in a debrief interview following the game. The findings of the two studies suggest that developing a verbal reporting protocol is viable, however when applied in a live-game environment it is problematic. Future research should therefore consider a modified version of this task to further explore the cognitions of scouts whilst observing and identifying potential talent.
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Affiliation(s)
- Matthew J. Reeves
- School of Sport & Health Sciences, University of Central Lancashire, Preston, Lancashire, United Kingdom
- * E-mail:
| | - Allistair P. McRobert
- The Football Exchange, School of Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
- School of Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Colin J. Lewis
- School of Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Simon J. Roberts
- School of Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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Marques PRR, Pinheiro EDS, Coswig VS. Efeito da idade relativa sobre a seleção de atletas para as categorias de base de um clube de futebol. REVISTA BRASILEIRA DE CIÊNCIAS DO ESPORTE 2019. [DOI: 10.1016/j.rbce.2018.03.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Abstract
The aims of this study were: i) to analyze whether relative age effect occurs in the athletes of the junior national teams and professional athletes in Spain in general and in soccer and basketball, and ii) to compare the long-term success of the players selected for the junior national team between these sports. The samples for this study were Spanish professional soccer (n = 461) and basketball (n = 250) players in the 2013-2014 premier league and players from the junior Spanish soccer (i.e., n = 273; U-17: n = 107; U-19: n = 166) and basketball (i.e., n = 240; U-18: n = 120, U-16: n = 120) teams that classified to play in the European Championships (from 2004 to 2013). Junior players (42.3%) were more frequently born in the 1st quarter of the year than the professional players (30.7%) (χ2(3) = 30.07; p = .001; Vc = .157). This was found in both basketball (χ2(3) = 12.2.; p = .007; Vc = .158) and soccer (χ2(3) = 20.13; p < .001; Vc = .166). Long-term success is more frequent in soccer, where 59.9% of the juniors selected for the national team played later in the premier league, while in basketball that percentage was 39.6% (χ2(1) = 14.64; p < .001; Vc = .201). On the other hand, 79.4% and 39.8% of the professional soccer and basketball players had been previously selected for junior national teams (χ2(1) = 60.2; p < .001; Vc = .386), respectively. The talent selection process should be reviewed as players born in the second half of the year have fewer opportunities to stand out.
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Abstract
The relative age effect (RAE) is related to discrimination against youth athletes born in the last quarter of the calendar year. The current study presents research on the RAE in elite youth soccer players in Poland. Players in the Central Junior League (CLJ) finals represent 0.59% of the 25,756 players under 20 years old (U20). This study analyzed the post-game protocols of the CLJ knockout stage from the 2013/2014 and 2014/2015 seasons as well as the U17-U21 teams during 2015, including only players who played on the field for at least one minute (n = 395). The results revealed the existence of RAE in the examined groups ( CLJ 2013/2014, χ23 = 15.441, p < 0.01, CLJ 2014/2015, χ23 = 20.891, p < 0.001 U17-U21, χ23 = 25.110, p < 0.001). In addition, the results differed by monthly birth distribution in the Polish population (PP) between 1995 and 1999. This study is the first to examine the RAE in youth soccer in Poland. The occurrence of the RAE with regard to the most promising youth and national team players suggests that a similar effect exists among younger age categories. To reduce the RAE related to identifying soccer talent, tools should be implemented to optimize the player-selection process, such as those that consider the biological development of a player.
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Affiliation(s)
- Krystian Rubajczyk
- Department of Team Games Sport, University School of Physical Education, Wroclaw, Poland
| | - Andrzej Rokita
- Department of Team Games Sport, University School of Physical Education, Wroclaw, Poland
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Rađa A, Padulo J, Jelaska I, Ardigò LP, Fumarco L. Relative age effect and second-tiers: No second chance for later-born players. PLoS One 2018; 13:e0201795. [PMID: 30089178 PMCID: PMC6082547 DOI: 10.1371/journal.pone.0201795] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/23/2018] [Indexed: 11/19/2022] Open
Abstract
The main objective of this research was to determine the existence of relative age effect (RAE) in five European soccer leagues and their second-tier competitions. Even though RAE is a well-known phenomenon in professional sports environments it seems that the effect does not decline over the years. Moreover, additional information is required, especially when taking into account second-tier leagues. Birthdates from 1,332 first-tier domestic players from France, England, Spain, Germany and Italy and birthdates from 1,992 second-tier domestic players for the 2014/2015 season were taken for statistical analysis. In addition to standard statistical tests, the data were analyzed using econometric techniques for count data using Poisson and negative binomial regressions. The results obtained confirmed a biased distribution of birthdates in favor of players born earlier in the calendar year. For all of the five first-tier soccer leagues there was an unequal distribution of birthdates (France χ2 = 40.976, P<0.001; England χ2 = 21.892, P = 0.025; Spain χ2 = 24.690, P = 0.010; Germany χ2 = 22.889, P = 0.018; Italy χ2 = 28.583, P = 0.003). The results for second-tier leagues were similar (France χ2 = 46.741, P<0.001; England χ2 = 27.301, P = 0.004; Spain χ2 = 49.745, P<0.001; Germany χ2 = 30.633, P = 0.001; Italy χ2 = 36.973, P<0.001). Econometric techniques achieved similar results: estimated effect of month of birth, i.e., long-term RAE on players' representativeness, is negative (statistically significant at the 1% level). On average, one month closer to the end of the year reduces the logs of expected counts of players by 6.9%. Assuming this effect as linear, being born in the month immediately before the cut-off date (i.e., December/August), reduces the logs of expected counts of players by approximately 75.9%. Further, ID (index of discrimination, that is, the ratio between the expected counts of players born in the middle of the first and the twelfth month of the selection year) is 2.13 and 2.22 for the first- and second-tier, respectively. In other words, in the top five European first-tier and second-tier leagues, one should expect the number of players born in the first month of the calendar year to be twice the number of those born in the last month. The RAE in the second-tiers is the same as in the first-tiers, so it appears that there is no second chance for later born players. This reduces the chances to recover talented players discarded in youth simply because of lower maturity.
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Affiliation(s)
- Ante Rađa
- University of Split, Faculty of kinesiology, Split, Croatia
| | - Johnny Padulo
- University of Split, Faculty of kinesiology, Split, Croatia
- University eCampus, Novedrate, Italy
- Tunisian Research Laboratory Sports Performance Optimization, National Center of Medicine and Science in Sport, Tunis, Tunisia
| | - Igor Jelaska
- University of Split, Faculty of kinesiology, Split, Croatia
| | - Luca Paolo Ardigò
- School of Exercise and Sport Science, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Luca Fumarco
- STATEC Research, Luxembourg, Grand Duchy of Luxembourg
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Barrenetxea-Garcia J, Torres-Unda J, Esain I, Gil SM. Relative age effect and left-handedness in world class water polo male and female players. Laterality 2018; 24:259-273. [PMID: 29855225 DOI: 10.1080/1357650x.2018.1482906] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Most studies of the relative age effect (RAE) refer to popular sports. In contrast, we examined to what extent the RAE is present in elite water polo players, as well as the association between handedness and RAE. For these purposes, laterality, anthropometry, month of birth, performance and playing position of participants in the 2011, 2013 and 2015 World Championships (623 women, 622 men) were analised. No RAE was observed in the total sample. However, the proportion of male left-handed field players born in the first quarter (11%) was lower than those born in the second (35.3%) and fourth quarter (29.4%). Regarding the overall laterality, the amount of left handed players was similar to the general population (10%). Nevertheless, there was a larger amount of left-handed wings than expected both in men (23.7%) and women (34.4%). Left-handed male players performed more shots, shots/minute and also scored more goals than right-handed players. Women left-handed players were younger and they performed more shots/minute. There is no RAE in elite male and female water polo players. However, laterality could be a possible moderator of the RAE particularly in left handed players, which should be taken into account in future studies.
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Affiliation(s)
- Josu Barrenetxea-Garcia
- a Department of Physiology, Faculty of Medicine and Nursing , University of the Basque Country (UPV/EHU) , Bizkaia , Basque Country, Spain
| | - Jon Torres-Unda
- a Department of Physiology, Faculty of Medicine and Nursing , University of the Basque Country (UPV/EHU) , Bizkaia , Basque Country, Spain
| | - Izaro Esain
- a Department of Physiology, Faculty of Medicine and Nursing , University of the Basque Country (UPV/EHU) , Bizkaia , Basque Country, Spain
| | - Susana M Gil
- a Department of Physiology, Faculty of Medicine and Nursing , University of the Basque Country (UPV/EHU) , Bizkaia , Basque Country, Spain
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Lagestad P, Steen I, Dalen T. Inevitable Relative Age Effects in Different Stages of the Selection Process among Male and Female Youth Soccer Players. Sports (Basel) 2018; 6:sports6020029. [PMID: 29910333 PMCID: PMC6026793 DOI: 10.3390/sports6020029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 03/28/2018] [Accepted: 03/29/2018] [Indexed: 12/02/2022] Open
Abstract
The relative age effect (RAE) in the selection of young soccer players is a well-known phenomenon. The purpose of this study was to examine the relative age effect existing despite strategies that have been implemented to avoid its presence in the selection process. We also aimed to investigate the RAE during the three different selection stages for B13, B14 (boys), and G13, G14 (girls), and gender differences in the RAE. This was achieved by collecting data from everyone who played soccer in Troendelag, and data that would illuminate the RAE during the three stages of selection for the regional teams of the 2015/2016 season. Mann–Whitney U-tests and Chi-square tests were used as statistical methods. The main finding of this study is that, despite the intention to reduce RAE in the selection process according to the criterion that at least 40% of the players should be born in the second half of the year, both the early-born boys and girls are more likely to be selected. The results also show that the RAE occurs gradually, and the longer the players are in the selection process the more prominent it is. This study highlights the importance of being aware of the RAE when selecting young players.
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Affiliation(s)
- Pål Lagestad
- Department of Physical Education and Sport Science, Nord University, 7600 Levanger, Norway.
| | - Ingebrigt Steen
- Department of Physical Education and Sport Science, Nord University, 7600 Levanger, Norway.
| | - Terje Dalen
- Department of Physical Education and Sport Science, Nord University, 7600 Levanger, Norway.
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Sæther SA, Peterson T, Matin V. The Relative Age Effect, Height and Weight Characteristics among Lower and Upper Secondary School Athletes in Norway and Sweden. Sports (Basel) 2017; 5:sports5040092. [PMID: 29910452 PMCID: PMC5969021 DOI: 10.3390/sports5040092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 12/01/2017] [Accepted: 12/07/2017] [Indexed: 11/16/2022] Open
Abstract
The relative age effect (RAE) has been found among youth elite athletes within a range of sports. However, the RAE has been studied to a lesser degree among youth non-elite athletes, and even less among school pupils attending sport specialisation programmes (SSPs). The aim of the present study was to investigate RAE, height, and weight, and compare Swedish lower secondary school and Norwegian upper secondary school pupils. Study 1 includes 156 lower secondary school athletes (95 boys and 61 girls) following an SSP in Sweden, while study 2 includes 111 upper secondary school athletes (81 boys and 30 girls) from two Norwegian schools. The RAE was found in both male groups, but only in Swedish girls. Furthermore, the relationship between birth month, height, and weight was found to be non-significant. These results indicate a vital RAE effect among youth non-elite athletes attending SSPs in both lower and upper secondary schools.
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Breznik K, Law KMY. Relative Age Effect in Mind Games: The Evidence from Elite Chess. Percept Mot Skills 2017; 122:583-94. [PMID: 27166336 DOI: 10.1177/0031512516640957] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Numerous studies have attempted to investigate the factors affecting superior intellectual performance, and it has been proposed that a possible biological marker for superior intellectual performance is the month of birth. In this study, birth details of chess players were obtained from the official international chess federation website. The rating lists of top junior female chess players ("Girls" category), top junior male chess players ("Boys"), top female chess players ("Female"), and top male chess players ("Male") were collected between July 2000 and August 2015. The birth months of each player that appeared in the top rating list were categorized into quarters. Additionally, relative age of chess players was calculated. Results supported the existence of the relative age effect in chess in all categories although a "reverse" RAE was found in the "Male" category.
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Affiliation(s)
- Kristijan Breznik
- International School for Social and Business Studies, Celje, Slovenia
| | - Kris M Y Law
- Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong
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Steingröver C, Wattie N, Baker J, Helsen WF, Schorer J. Geographical Variations in the Interaction of Relative Age Effects in Youth and Adult Elite Soccer. Front Psychol 2017; 8:278. [PMID: 28326044 PMCID: PMC5339226 DOI: 10.3389/fpsyg.2017.00278] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 02/14/2017] [Indexed: 11/23/2022] Open
Abstract
Selection biases based on the use of cut-off dates and the timing of athletes’ birthdates have been termed relative age effects. These effects have been shown to differentially affect individuals involved in sport. For example, young male soccer players born early in their age group are overrepresented in elite teams while studies in adult soccer indicated potential carry-over effects from talent development systems. This two-study approach focuses on the processes within multi-year age groups in youth and adult elite soccer and on the role of players’ age position within the age band with regard to players’ birth year and birth month. Study 1 tests for an interaction of two different types of relative age effects among data from participants in the last five Under-17 FIFA World Cups (2007–2015). Analyses revealed a significant global within-year effect and varying birthdate distributions were found between confederations. Even stronger effects were found for constituent year effects. For the total sample, a multi-way frequency analysis (MFA) revealed an interaction with a pattern of a stronger within-year effect for the younger year group. This study highlights the need to consider interactions between different types of age effects. The main aim of Study 2 was to test for carry-over effects from previously found constituent year effects among players participating in the 2014 soccer World Cup and, therefore, to test for long-term effects of age grouping structures used during earlier stages of talent development. A secondary purpose of this study was to replicate findings on the existence of within-year effects and to test whether effects vary between continental confederations. No significant interaction between constituent year and within-year effects was shown by the MFA among the World Cup sample and previous findings on varying within-year effects were replicated. Results indicate that long-term effects of age grouping structures in earlier high-level talent development structures exist.
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Affiliation(s)
- Christina Steingröver
- Department of Sport and Motion, Institute of Sport Science, University of Oldenburg Oldenburg, Germany
| | - Nick Wattie
- Faculty of Health Sciences, University of Ontario Institute of Technology, Oshawa ON, Canada
| | - Joseph Baker
- School of Kinesiology and Health Science, York University, Toronto ON, Canada
| | - Werner F Helsen
- Department of Kinesiology, Research Centre for Movement Control and Neuroplasticity, KU Leuven Leuven, Belgium
| | - Jörg Schorer
- Department of Sport and Motion, Institute of Sport Science, University of Oldenburg Oldenburg, Germany
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Sierra-Díaz MJ, González-Víllora S, Pastor-Vicedo JC, Serra-Olivares J. Soccer and Relative Age Effect: A Walk among Elite Players and Young Players. Sports (Basel) 2017; 5:sports5010005. [PMID: 29910365 PMCID: PMC5969014 DOI: 10.3390/sports5010005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 01/02/2017] [Accepted: 01/03/2017] [Indexed: 11/30/2022] Open
Abstract
Grouping people according to chronological age is popular in fields such as education and sport. Athletes who are born in the first months of the year usually have cognitive and physical development differences in contrast to those born in the last months of the same year. That is why competitive teams tend to select older players more often than youngsters. Age differences between athletes born in the same year as well as an over-representation of older players are known as the Relative Age Effect. This effect is extensively described in young and elite team sports such as basketball, volleyball or, ice-hockey, as well as in soccer. The purpose of this study is to examine the state-of-the-art of the Relative Age Effect in youth and elite soccer players. This review summarizes recent research articles on the Relative Age Effect related to competitive soccer from 2010 to 2016. The systematic literature search was conducted in four databases: SPORTDiscus, Medline, EBSCO host and Google Scholar. Although causes and final solutions have not been clearly achieved yet, it is necessary to continue investigating this phenomenon in order to provide a starting point for future research.
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Affiliation(s)
- Manuel Jacob Sierra-Díaz
- Physical Education Department, Teaching Training Faculty, University of Castilla-La Mancha, 16071 Cuenca, Spain.
| | - Sixto González-Víllora
- Physical Education Department, Teaching Training Faculty, University of Castilla-La Mancha, 16071 Cuenca, Spain.
| | - Juan Carlos Pastor-Vicedo
- Physical Education Department, Teaching Training Faculty, University of Castilla-La Mancha, 45004 Toledo, Spain.
| | - Jaime Serra-Olivares
- Department of Physical Education Pedagogy, Faculty of Education, Catholic University of Temuco, 02950 Rudecindo Ortega, Temuco, Chile.
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Arrieta H, Torres-Unda J, Gil SM, Irazusta J. Relative age effect and performance in the U16, U18 and U20 European Basketball Championships. J Sports Sci 2015; 34:1530-4. [PMID: 26666180 DOI: 10.1080/02640414.2015.1122204] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This study sought to determine the association of relative age and performance of young elite basketball players. The distribution of the birth dates, heights, positions, classification and performance of the male and female participants (n = 2395) of the U16, U18 and U20 European Basketball Championships were analysed. We found an over-representation of players born during the initial months of the year in all groups, with the relative age effect being more evident in players of the U16 and U18 groups, than of the U20 teams, particularly in male squads. Nevertheless, in the U20 championships, those teams that had the oldest players performed the best. In all championships, the oldest participants played more minutes. In addition, relatively older male players scored better in total points and in performance index rating when results were normalised to played time. This effect was not found for female players. Regarding playing position, different distributions of birth dates were observed due to each position's physical requirements. Thus, basketball coaches and managers should keep these results in mind when they select players because if not, they might subject players who are born towards the end of the year to a negative selection bias.
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Affiliation(s)
- Haritz Arrieta
- a Department of Physiology, Faculty of Medicine and Dentistry , University of the Basque Country (UPV/EHU) , Leioa , Spain
| | - Jon Torres-Unda
- a Department of Physiology, Faculty of Medicine and Dentistry , University of the Basque Country (UPV/EHU) , Leioa , Spain
| | - Susana María Gil
- a Department of Physiology, Faculty of Medicine and Dentistry , University of the Basque Country (UPV/EHU) , Leioa , Spain
| | - Jon Irazusta
- a Department of Physiology, Faculty of Medicine and Dentistry , University of the Basque Country (UPV/EHU) , Leioa , Spain
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Andrade-Souza VA, Moniz F, Teoldo I. Relative age effect in FIFA U17 Emirates 2013 World Cup: analysis of players who effectively participated in the matches. MOTRIZ: REVISTA DE EDUCACAO FISICA 2015. [DOI: 10.1590/s1980-65742015000400009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Abstract The purpose of this study was to verify the date of birth is a decisive factor for the success of players selected by the coaches to participate in the FIFA U-17 World Cup Emirates 2013. The players' date of birth were classified into four quartiles of three months each (Q1 to Q4). In the qualifying round, 46.5% of the selected players born in Q1, while 12.5% in Q4. This significantly different distribution occurred until the semi-finals. However, in the final match, there were no significant differences between Q1 and Q4. A similar relative age effect also occurred when analyzed only players who actually participated to the matches. Interestingly, despite there was birth date effect on performance in all World Cup stages except in the final, other issues should take into consideration for a team became champion.
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Sæther S. Selecting players for youth national teams – a question of birth month and reselection? Sci Sports 2015. [DOI: 10.1016/j.scispo.2015.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Andronikos G, Elumaro AI, Westbury T, Martindale RJJ. Relative age effect: implications for effective practice. J Sports Sci 2015; 34:1124-31. [PMID: 26417709 DOI: 10.1080/02640414.2015.1093647] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Physical and psychological differences related to birthdate amongst athletes of the same selection year have been characterised as the "relative age effects" (RAEs). RAEs have been identified in a variety of sports, both at youth and adult level, and are linked with dropout of athletes and a reduction of the talent pool. This study examined the existence, mechanisms and possible solutions to RAEs using qualitative methodology. Seven experts in the field of talent identification and development were interviewed. Inductive analysis of the data showed that, while there was mixed evidence for the existence of RAEs across sports, the eradication of RAEs was attributed to controllable features of the development environment. The factors reported included the structure of "categories" used to group athletes within the sport (e.g. age, weight, size, skills), recognition and prioritisation of long-term development over "short term win focus." Education of relevant parties (e.g. coaches, scouts, clubs) about RAEs and the nature of "talent" within a long-term context was suggested, along with careful consideration of the structure of the development environment (e.g. delayed selection, provision for late developers, focus on skills not results, use of challenge). Implications for research and practice are discussed.
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Affiliation(s)
- Georgios Andronikos
- a School of Life, Sport and Social Sciences , Edinburgh Napier University , Edinburgh , UK
| | - Adeboye Israel Elumaro
- a School of Life, Sport and Social Sciences , Edinburgh Napier University , Edinburgh , UK
| | - Tony Westbury
- a School of Life, Sport and Social Sciences , Edinburgh Napier University , Edinburgh , UK
| | - Russell J J Martindale
- a School of Life, Sport and Social Sciences , Edinburgh Napier University , Edinburgh , UK
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Sedano S, Vaeyens R, Redondo JC. The Relative Age Effect in Spanish Female Soccer Players. Influence of the Competitive Level and a Playing Position. J Hum Kinet 2015; 46:129-37. [PMID: 26240656 PMCID: PMC4519203 DOI: 10.1515/hukin-2015-0041] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The purposes of the study were to examine relative age effects (RAEs) in Spanish female soccer and to identify the influence of a playing position. The sample comprised all female players (n=4035) of five different competitive levels in the 2010–2013 seasons: First, Second and Third divisions (n=936, n=1711 and n=870, respectively), and National and Regional (n=232 and n=286, respectively) teams were included. Differences between the observed and expected birth-date distributions were tested based on data from the general Spanish population, using the chi-square statistic followed up by calculating odds ratios and 95% confidence intervals. Results revealed that the birth-date distributions of almost all groups of football players showed an overrepresentation of players born in the first quartile. Only in the lowest level was age distribution not significantly different from that of the general population. Moreover, the RAE risk progressively increased with a higher level of involvement. It was also observed that at some playing positions the birth-date distributions were significantly biased. That was the case for goalkeepers and defenders. It could be concluded that in the current structure of Spanish female soccer there is a relative age effect, probably due to the early processes of talent identification.
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Affiliation(s)
- Silvia Sedano
- Laboratory of Physiology. European University Miguel de Cervantes, Valladolid, Spain
| | - Roel Vaeyens
- Ghent University, Department of Movement and Sports Sciences, Belgium
| | - Juan Carlos Redondo
- Faculty of Sports Sciences, Department of Movement and Sport Sciences, University of León, Spain
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Coutts AJ, Kempton T, Vaeyens R. Relative age effects in Australian Football League National Draftees. J Sports Sci 2014; 32:623-8. [DOI: 10.1080/02640414.2013.847277] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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37
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Gastin PB, Bennett G. Late maturers at a performance disadvantage to their more mature peers in junior Australian football. J Sports Sci 2013; 32:563-71. [DOI: 10.1080/02640414.2013.843016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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38
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Gil SM, Badiola A, Bidaurrazaga-Letona I, Zabala-Lili J, Gravina L, Santos-Concejero J, Lekue JA, Granados C. Relationship between the relative age effect and anthropometry, maturity and performance in young soccer players. J Sports Sci 2013; 32:479-86. [PMID: 24050650 DOI: 10.1080/02640414.2013.832355] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The presence of the relative age effect (RAE) has been widely reported; however, its underlying causes have not yet been determined. With this in mind, the present study examined if anthropometry and performance were different amongst older and younger soccer players born in the same year. Eighty-eight young soccer players participated in the study (age 9.75 ± 0.30). Anthropometric measurements, physical tests (sprint, agility, endurance test, jump and hand dynamometry) and the estimation of the maturity status were carried out. Most players (65.9%) were born in the first half of the year. Older players were taller (P < 0.05), had longer legs (P < 0.01) and a larger fat-free mass (P < 0.05). Maturity offset was smaller in the older boys (P < 0.05); however, age at peak height velocity was similar. Older boys performed better in velocity and agility (P < 0.05) and particularly in the overall score of performance (P < 0.01). Stepwise regression analysis revealed that chronological age was the most important variable in the agility test and the overall score, after the skinfolds (negative effect). We report differences in anthropometry and physical performance amongst older and younger pre-pubertal soccer players. These differences may underlie the RAE.
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Affiliation(s)
- Susana Maria Gil
- a Department of Physical Education and Sport , University of the Basque Country (UPV/EHU) , Vitoria-Gasteiz , Spain
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Votteler A, Höner O. The relative age effect in the German Football TID Programme: Biases in motor performance diagnostics and effects on single motor abilities and skills in groups of selected players. Eur J Sport Sci 2013; 14:433-42. [DOI: 10.1080/17461391.2013.837510] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
The aim of this study was to investigate whether weight categories prevent young athletes from being exposed to a relative age effect. The dates of birth of all French female (n = 727) and male (n = 5440) amateur boxers who participated in the 2010-2011 season were collected from the federation database. The dates of birth of all French male professional boxers (n = 354) were also collected. The results show an absence of a relative age effect among French female and male amateur boxers. The results also show an absence of this phenomenon among French male professional boxers. The male 18-18+ age category reveal an inverse relative age effect. This inverse relative age effect might be interpreted as the result of a strategic adaptation from relatively younger children who shift from one sport to another where there are weight categories in order to ensure fair competition. The results of this study suggest that the weight category system is a possible solution within the relative age effect phenomenon.
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Affiliation(s)
- Nicolas Delorme
- a University of Bordeaux, Laboratoire Cultures, Education, Sociétés , Bordeaux , France
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Schorer J, Wattie N, Baker JR. A new dimension to relative age effects: constant year effects in German youth handball. PLoS One 2013; 8:e60336. [PMID: 23637745 PMCID: PMC3637174 DOI: 10.1371/journal.pone.0060336] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 02/25/2013] [Indexed: 11/18/2022] Open
Abstract
In this manuscript we argue for a broader use of the term 'relative age effect' due to the influence of varying development policies on the development of sport expertise. Two studies are presented on basis of data from Schorer, et al. [1]. The first showed clear 'constant year effects' in the German handball talent development system. A shift in year groupings for the female athletes resulted in a clear shift of birth year patterns. In the second study we investigated whether the constant year effect in the national talent development system carried over to professional handball. No patterns were observable. Together both studies show that a differentiation of varying effects that often happen simultaneously is necessary to understand the secondary mechanisms behind the development of sport expertise.
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Affiliation(s)
- Jörg Schorer
- Institute of Sport and Exercise Sciences, University of Muenster, Münster, Institute for Sport Science, University of Oldenburg, Oldenburg, Germany.
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Abstract
The purpose of this review article was firstly to evaluate the traditional approach to talent identification in youth soccer and secondly present pilot data on a more holistic method for talent identification. Research evidence exists to suggest that talent identification mechanisms that are predicated upon the physical (anthropometric) attributes of the early maturing individual only serve to identify current performance levels. Greater body mass and stature have both been related to faster ball shooting speed and vertical jump capacity respectively in elite youth soccer players. This approach, however, may prematurely exclude those late maturing individuals. Multiple physiological measures have also been used in an effort to determine key predictors of performance; with agility and sprint times, being identified as variables that could discriminate between elite and sub-elite groups of adolescent soccer players. Successful soccer performance is the product of multiple systems interacting with one another. Consequently, a more holistic approach to talent identification should be considered. Recent work, with elite youth soccer players, has considered whether multiple small-sided games could act as a talent identification tool in this population. The results demonstrated that there was a moderate agreement between the more technically gifted soccer player and success during multiple small-sided games.
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Affiliation(s)
- Viswanath Unnithan
- Staffordshire University, Centre for Sport, Health and Exercise Research, Stoke-on-Trent, United Kingdom.
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Romann M, Fuchslocher J. Influences of player nationality, playing position, and height on relative age effects at women's under-17 FIFA World Cup. J Sports Sci 2012; 31:32-40. [PMID: 22909307 DOI: 10.1080/02640414.2012.718442] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Previous research has shown that young male soccer players who are born early in a cohort are overrepresented on elite soccer teams. Selection advantages such as this have been termed 'relative age effects' (RAEs). Few studies have examined RAEs in elite women's youth soccer. Therefore, the aim of this study is to investigate the occurrence of RAEs in the Fédération Internationale de Football Association (FIFA) U-17 Women's World Cup competition and their link to playing positions. In the entire cohort of 672 players, we found significant RAEs in the geographical zones of Europe and North and Central America, no RAEs in the zones of Asia, Oceania, and South America, and significant inverse RAEs in the zone of Africa. Additionally, significant RAEs were found for goalkeepers and defenders from Europe and North and Central America. Inverse RAEs occurred for African goalkeepers, defenders, and strikers. Goalkeepers of all zones were significantly taller than players of all other playing positions. The results of this study show that remarkable RAEs do exist at elite women's youth soccer. Similar to men's soccer, there is a bias toward the inclusion of relatively older players, and a link between RAEs and playing positions.
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Affiliation(s)
- Michael Romann
- Swiss Federal Institute of Sport, Magglingen, Switzerland.
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Baker J, Janning C, Wong H, Cobley S, Schorer J. Variations in relative age effects in individual sports: skiing, figure skating and gymnastics. Eur J Sport Sci 2012; 14 Suppl 1:S183-90. [PMID: 24444205 DOI: 10.1080/17461391.2012.671369] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
In many sports, policy-makers and administrators employ annual cohorts to reduce differences between athletes during childhood and youth. Although well-intended, unintended relative age effects (RAEs) usually occur. RAEs refer to the specific selection, participation and attainment disadvantages associated with participants' birthdates relative to an arbitrary 'cutoff' date used to group participants within annual age groups. To date, we have little understanding of RAEs in individual sports. In this article, Study 1 considered the presence of RAEs in 1474 ski jumping, 7501 cross-country skiing, 15,565 alpine skiing, 4179 snowboarders and 713 Nordic combined athletes. Chi-square analyses revealed significant RAEs for most of these contexts across sexes. In Study 2, RAEs in the aesthetic sports of figure skating (n=502) and female gymnastics (n=612) were considered. There was no effect for the figure skaters and an atypical effect for the gymnasts. The significant effects across most ski sports coupled with the null effects in figure skating and atypical effect in gymnastics suggest that sport-specific contextual factors are important elements in understanding the mechanisms of RAEs, although further work is necessary to validate these findings.
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Affiliation(s)
- Joseph Baker
- a School of Kinesiology and Health Science , York University , Toronto , ON , Canada
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Delorme N, Radel R, Raspaud M. Relative age effect and soccer refereeing: a 'strategic adaptation' of relatively younger children? Eur J Sport Sci 2011; 13:400-6. [PMID: 23834546 DOI: 10.1080/17461391.2011.635703] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Previous research suggested that the relative age effect (RAE) has a psychological influence on children and their decision to engage in a particular sport. Relatively younger children seem to have lower self-esteem. Indeed, because of the disadvantages of being younger, it is assumed that these players experience more situations of failure and inferiority. Because of these negative performance cues, it is likely that these young players feel less competent, which eventually leads to a higher dropout rate. These children can also decide to participate in sports in which physical attributes are less important. This shift from one sport to another can be interpreted as a 'strategic adaptation'. The purpose of this study was thus to investigate whether refereeing could be another form of 'strategic adaptation'. If a child chooses a specific sport but then does not feel competent enough to be a player, refereeing might be an alternate path followed to stay in the environment of a sport they like. Given the minimal age limits for refereeing, two hypotheses were formulated: (1) 'reversed' RAE would be observed in district referees younger than 18 years old and (2) no RAE would be observed in district referees older than 18 years old, regional referees and national referees. The birthdates of all official male soccer referees (n=13,952) were collected from the federation database. Results show that the distribution of all district referees was significantly unbalanced (χ(2)=18.73, df=3, P<0.001) with an over-representation of individuals who were born in the second half of the competitive year. As expected, this imbalance was exclusively located in district referees of 18 years old and less (χ(2)=8.03, df=3, P<0.05), while the distribution was uniform for adults (χ(2)=5.17, df=3, P<0.16). Concerning regional referees (χ(2)=2.09, df=3, P<0.554) and national referees (χ(2)=3.75, df=3, P<0.290), the results also provide support for our initial hypothesis as uniform distributions were found for both groups. This study brings to light new elements in the potential relationship between relative age and refereeing. Qualitative and/or longitudinal research is needed to confirm our quantitative data.
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Affiliation(s)
- Nicolas Delorme
- Laboratoire Sport et Environnement Social, Université Joseph Fourier, Grenoble, France.
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