Predictability of physiological testing and the role of maturation in talent identification for adolescent team sports

Development of Physical Fitness among the Top 10 Boys and Girls in Sport Schools: A 10-Year Cohort Analysis

In this study, we aimed to measure the development of physical fitness (PF) of 10 different cohorts in grade 4 and 8 different cohorts in grade 7 at 18 sport schools of North Rhine-Westphalia, Germany. A total of 11,451 subjects (3979 female, 7472 male) aged 8–12 from the past 10 years were assessed using the German Motor Test (DMT) in grade 4. We tested 2614 subjects (1032 girls, 1582 boys) aged 11–15 from the past eight years using the DMT in grade 7. PF talents were defined as the top 10 boys and top 10 girls of each cohort. Linear regression was calculated to assess the development of PF. The PF of all subjects remained stable in grade 4 and declined in grade 7. The PF of the top 10 boys and top 10 girls increased in both grades. The improvements were stronger in grade 7 (female: rates of change (β) = 0.80; male: β = 0.76) than in grade 4 (female: β = 0.36; male: β = 0.32). Sit-ups and push-ups showed the highest change rates. The increase in PF of the top 10 boys and girls can be interpreted as a success for sport schools. Due to the increasing number of test participants, the likelihood of finding top talent increased. However, the increase in PF in the top talents was only partly explained by an increase in the number of tested individuals.

TALENTO MOTOR E MATURAÇÃO BIOLÓGICA EM ESCOLARES DE UM COLÉGIO MILITAR

RESUMO Introdução A avaliação do desempenho motor em escolares tem sido utilizada na identificação de talentos esportivos. Porém, existem poucos estudos, sobre esta temática, e nenhum no Sistema Colégio Militar do Brasil. Objetivo Avaliar indicadores antropométricos, fisicomotores e maturacionais; investigar a proporção de talentos motores; analisar a relação entre o diagnóstico de talento motor e o estágio maturacional; e comparar o perfil de alunos-atletas e não atletas de um colégio militar. Métodos Foram avaliados 1.490 escolares de ambos os sexos, de 11 a 17 anos. Aplicou-se uma bateria de testes multidimensional para avaliação do tamanho e da composição corporal, flexibilidade, força de preensão manual, força explosiva de membros superiores e inferiores, velocidade, resistência aeróbica e maturação somática. Os dados foram analisados por meio do teste qui-quadrado e análise de covariância. Resultados Os escolares apresentaram maior tamanho corporal, maior desempenho motor e maturação biológica discretamente avançada em relação aos dados disponíveis na literatura. Além disso, foram criados pontos de corte para oito testes relacionados com a prática esportiva, para identificar escolares com resultados muito acima da média, sendo encontrados 11% de talentos motores. Constatou-se ainda que os talentos motores foram mais frequentes nos escolares avançados biologicamente, e que os alunos-atletas apresentaram diferenças significativas em relação aos não atletas, principalmente quanto ao desempenho motor. Conclusão Os escolares do colégio militar são maiores, mais fortes, mais resistentes e mais maduros biologicamente quando comparados aos valores de referência da literatura, e tais características acentuam-se nos alunos-atletas. Além disso, aproximadamente um em cada dez escolares do colégio militar pode ser considerado um talento motor, e este diagnóstico é mais frequente nos escolares com maturação precoce. Nível de evidência II; Estudo diagnóstico.

Field Tests of Performance and Their Relationship to Age and Anthropometric Parameters in Adolescent Handball Players

Handball performance is influenced by age, anthropometric characteristics, technical skills, tactical understanding, and physical abilities. The aims of this study were (i) to determine differences in anthropometric characteristics and physical performance between adolescent handball players across age categories, and (ii) to determine which anthropometric and maturity variables have the greatest relative importance in fitness for this sport. Seventy-nine male handball players drawn from a team in the elite Tunisian Handball league [U18 (n = 10); U17 (n = 12); U16 (n = 17); U15 (n = 18); and U14 (n = 22)] volunteered for the investigation. Assessments included sprint performances; change in direction tests (T-half test and Illinois modified test); jumping tests (squat jump; counter movement jump; countermovement jump with aimed arms; five-jump test); medicine ball throwing; handgrip force; back extensor force and selected anthropometric measurements. The individual's age category affected all measurements, with U17 and U18 players showing larger body measurements and significantly better absolute results on all physical tests than U14, U15 and U16 contestants. Scores for the majority of physical performance tests were closely inter-correlated. We conclude that U17 and U18 players show significantly better absolute results than the younger players on all physical tests. Multiple linear regressions, using block-wise entry, indicate that age is the strongest predictor of jump and sprint performances. Several anthropometric characteristics, including body mass, standing height and lower limb length were closely correlated with performance test scores, but after allowing for age only body mass added to the prediction of jumping ability.

Jump higher, run faster: effects of diversified sport participation on talent identification and selection in youth basketball

The aims of this study were to examine the medium-term effects of previous experiences during early stages of sport development on physical capacities of under-13 (U-13) talented basketball players and, to identify variables that discriminated under-14 (U-14) national team training camp selection. Anthropometrical and physical measurements were collected during a basketball training camp. Previous sport experiences (6-10 years), maturity offset, power outputs for jumping and sprinting were determined. A cluster analysis was used to allocate the subjects according to their different levels of sport experiences (more specialized vs. less specialized) to allow creating a dummy variable for the subsequent analysis of the physical variables. A stepwise discriminant analysis was computed to identify the construct that best classifies selected and non-selected players for U-14 national team training camp. The less specialized group outscored more specialized in all physical parameters, irrespectively of gender. The Abalakov Jump Peak Power and Predicted Adult Height (PAH) could successfully discriminate selected from non-selected players for U-14 national team training camp in boys and PAHin girls. The diversified and non-specific sport stimulus during early ages seem to be determinant to the acquisition and development of fundamental movement skills of talented basketball players.

Effect of COL5A1, GDF5, and PPARA Genes on a Movement Screen and Neuromuscular Performance in Adolescent Team Sport Athletes

Stastny, P, Lehnert, M, De Ste Croix, M, Petr, M, Svoboda, Z, Maixnerova, E, Varekova, R, Botek, M, Petrek, M, Lenka, K, and Cięszczyk, P. Effect of COL5A1, GDF5, and PPARA genes on a movement screen and neuromuscular performance in adolescent team sport athletes. J Strength Cond Res 33(8): 2057-2065, 2019-The risk of injury increases with adolescents' chronological age and may be related to limited muscle function neuromuscular, genetic, and biomechanical factors. The purpose of this study was to determine whether COL5A1, PPARA, and GDF5 genes are associated with muscle functions and stretch-shortening cycle performance in adolescent athletes. One hundred forty-six youth players (14.4 ± 0.2 years) from various team sports (basketball n = 54, soccer n = 50, handball n = 32) underwent a manual test for muscle function, maturity estimation, functional bend test (FBT), passive straight leg raise (SLR) test, leg stiffness test, test of reactive strength index (RSI), and gene sampling for COL5A1, PPARA, and GDF5. The χ test did not show any differences in allele or genotype frequency between participants before and after peak height velocity. Multivariate analysis of variance showed that COL5A1 rs12722 CT heterozygotes had worse score in FBT (p < 0.001), worse score in SLR (p = 0.003), and lower maturity offset (p = 0.029, only in females) than TT homozygotes. Male GDF5 rs143383 GG homozygotes showed better score in SLR than AA and AG genotypes (p = 0.003), and AA and AG genotypes in both sex had greater RSI than GG homozygotes (p = 0.016). The PPARA rs4253778 CC homozygotes had greater RSI than GG and GC genotypes (p = 0.004). The CT genotype in COL5A1 rs12722 is possible predictor of functional movement disruption in the posterior hip muscle chain, causing shortening in FBT and SLR, which includes hamstrings function. CT genotype in COL5A1 rs12722 should be involved in programs targeting hamstring and posterior hip muscle chain.

Longitudinal Changes of Functional Capacities Among Adolescent Female Basketball Players

Background: The interpretation of young athletes' performance during pubertal years is important to support coaches' decisions, as performance may be erroneously interpreted due to the misalignment between chronological age (CA), biological age (BA) and sport age (SA). Aim: Using a Bayesian multilevel approach, the variation in longitudinal changes in performance was examined considering the influence of CA, BA (age at menarche), SA, body size, and exposure to training among female basketball players. Method: The study had a mixed-longitudinal design. Thirty eight female basketball players (aged 13.38 ± 1.25 years at baseline) were measured three times per season. CA, BA and SA were obtained. Anthropometric and functional measures: countermovement jump, Line drill (LD), Yo-Yo (Yo-Yo IR1). Based on the sum of the z-scores, an index of overall performance was estimated. The effects of training on longitudinal changes in performance were modeled. Results: A decrease in the rate of improvements was apparent at about 14 years of age. When aligned for BA, the slowing of the rate of improvements is apparent about 2 years after menarche for LD. For countermovement jump longitudinal changes, when performance was aligned for BA improvements became linear. For Yo-Yo IR1 and performance index, both indicators showed a linear trend of improvement when aligned for CA and BA, separately. Older players showed higher rates of improvement for Yo-Yo IR1 and performance index from pre-season to end-season. When considering performance changes aligned for BA it was apparent an improvement of performance as players became biologically mature. Conclusions and Implications: The alignment of CA with BA and SA provides important information for coaches. Human growth follows a genetically determined pattern, despite variation in both tempo and timing. When the effects of maturation reach their end, all the girls went through the same process. Hence, there is no need to artificially manipulate youth competitions in order to accelerate gains that sooner or later reach their peak and tend to flat their improvement curve.

Determinants of drop-out in youth basketball: an interdisciplinary approach

Using an interdisciplinary approach, we examined the baseline variation in biological maturity status, training experience, body size, functional capacities (Line Drill test and Yo-Yo Intermittent Recovery level 1 test) and motivation for achievement, competitiveness and deliberate practice of youth basketball players according to their participation status in the sport two years after assessment. Fifty-seven players were considered (10.5 to 15.5 years). Two years later we ascertained whether players discontinued participation (dropout), or remained playing engaged within a structured basketball training program. Taller adolescent players were more likely to be selected/promoted in youth basketball regardless of their lower functional capacity. Achievement and competitiveness motivation (will to excel and competitiveness) were related to dropping out or persisting in this sample of youth basketball players. Overall, there is a need to consider the interaction between physical growth, biological maturation, functional capacities and behavioural characteristics, specifically among players on the path to sport expertise.

Differences in maturity, morphological and physical attributes between players selected to the primary and secondary teams of a Portuguese Basketball elite academy

The present study aims (i) to compare the maturational, morphological and fitness attributes of young basketball players of primary and secondary teams of an elite basketball academy, and (ii) to identify the set of morphological and fitness attributes which better discriminate the players from the two teams. A total of 116 male basketball players of an elite basketball academy were divided into primary (team A) and secondary (team B) teams in two age groups (U-14 and U-16). All the players were evaluated during two consecutive seasons and data related to players' practice experience, maturational, morphological and fitness attributes were collected at the beginning of the competition period. The results of the study suggest that: (i) in both age categories, team A players were older, more mature, bigger in size and had greater fitness profiles than team B players; (ii) stature and abdominal resistance were identified as discriminant attributes for youth basketball player performance; (iii) aerobic capacity for U-14 and agility for U-16 were identified as specific discriminant attributes for performance in youth basketball. Coaches are recommended to avoid premature talent identification and provide players with opportunities to progress through the talent pathway, at least until U-16 age category.

Australian Football Skill-Based Assessments: A Proposed Model for Future Research

Identifying sporting talent remains a difficult task due to the complex nature of sport. Technical skill assessments are used throughout the talent pathway to monitor athletes in an attempt to more effectively predict future performance. These assessments, however, largely focus on the isolated execution of key skills devoid of any game context. When assessments are representative of match-play and applied in a setting where all four components of competition (i.e., technical, tactical, physiological, and psychological) are assessed within an integrated approach, prediction of talent is more likely to be successful. This article explores the current talent identification technical skill assessments, with a particular focus on Australian Football, and proposes a 5-level performance assessment model for athlete assessment. The model separates technical game skill on a continuum from Level-1 (i.e., laboratory analysis) to Level-5 (i.e., match-play). These levels, using the assumptions of the expert performance model and representative learning design theory, incorporate a step-wise progression of performance demands to more closely represent match-play conditions. The proposed model will provide researchers and practitioners with a structured framework to consider when assessing, or developing, new assessments of technical game-based skill.

Leistung beschreiben, erklären, vorhersagen und optimieren

Zusammenfassung. Im vorliegenden Artikel wird anlässlich des 50-jährigen Bestehens der asp der Beitrag der Sportpsychologie zum Verständnis von Leistung anhand von vier Leitfragen resümiert, die den Grundanliegen der Psychologie als Wissenschaftsdisziplin folgen: Wie zeigt sich Leistung im Sport und wie lässt sie sich aus psychologischer Perspektive beschreiben? Wie lässt sich das Zustandekommen von Leistung erklären? Was können wir über das Entstehen von Leistung vorhersagen? Wie können wir Leistung optimieren? Im Spannungsfeld von Sport und Leistung steht die menschliche Höchstleistung. Damit einher gehen die Betrachtung der Expertise der Sportlerinnen und Sportler und der Erwerb von Expertise im Sport. Die Talentförderung im Leistungssport wird folglich als inhaltlicher Schwerpunkt gewählt. Sie erlaubt es, die Verbindung zwischen Phänomenen des Leistungssports, Erkenntnisinteresse der Wissenschaft, Erklärungsansätzen, Forschungsergebnissen und Praxistransfer herzustellen. Der Praxistransfer wird anhand eines Überblicks über die praxisbezogenen Beiträge der Zeitschrift für Sportpsychologie und ihrer Vorgänger_innen beleuchtet. Fazit und Ausblick fassen die Ausführungen zusammen und erörtern zukünftige Aufgaben.

Sports potential modeling of young basketball players: a preliminary analysis

Abstract The aims of this study were: 1) to evaluate the sports potential of young basketball players; 2) to identify variables that discriminate sports potential assessed by coaches; 3) to verifythe relationship between classification of the multidimensional profile of athletes and classification of the sports potential by coaches. Sixty-two young basketball players aged 15.6±1.1 years from U-15 (n = 24) and U-17 (n = 38) categories participated in the study. A test battery was applied to evaluate sports potential indicators: 1) anthropometric; 2) physicomotor; 3) psychological;4) skills;5) socio-environmental;6) maturational and 7) sports potential.Clusteranalysis was performed in three groups: high, medium and low potential. Student’s t-test was used for the comparison between athletes evaluated by the coach as excellent and the others and the Chi-Square test to verify the relationship between sports potential classifications. It was observed that in the high-potential group, athletes were chronologically older, with higher % predicted adult height (PMS), competitive and determined sports orientation, higher body size, lower skinfold summation, and greater physicomotor performance. In comparison with other athletes, high-potential basketball players presented higher stature, wider wingspan,longer limb length, greater predicted adult stature and higher Z score of the % PMS. It could be concluded that the multidimensional approach was useful for the evaluation of the sports potential of young basketball players, requiring the use of multidimensional variables, in addition to coaches’ opinion regarding the potential of their athletes.

Comparison of maturation and physical performance in basketball athletes of different playing positions

Abstract The aim of this study was to compare the characteristics of somatic maturation, anthropometric and physical performance (vertical jump and aerobic power) in young basketball players of different playing positions (under 13 years) and analyze these relationships using Peak Height Velocity (PHV) as a measure of somatic maturation. For this, 26 male athletes were evaluated. Anthropometric variables were: body mass, standing and sitting height, and length of lower limbs. Maturation was determined by age at PHV. Physical performance was determined by lower limb power (counter movement jump - CMJ) and aerobic power (Intermittent Recovery Test) tests. MANOVA reported significant differences (p<0.05) among playing positions regarding variables Maturity Offset, estimated PHV age, standing height, sitting height, estimated leg length, body mass and Yo-Yo IR1. In addition, it was identified that point guards reached estimated PHV at later age than their peers who act as small forwards and centers. Regarding CMJ, no significant differences were identified among playing positions, but in relation to aerobic power, point guards and small forwards presented higher performance. These findings confirm that maturation has great effect on growth and physical performance measures and the estimated PHV age is an applicable tool in young athletes, mainly aiding professionals in structuring the teaching-learning- training process in this age group.

Reliability and validity of field-based fitness tests in youth soccer players

This study aimed to establish between-day reliability and validity of commonly used field-based fitness tests in youth soccer players of varied age and playing standards, and to discriminate between players without ("unidentified") or with ("identified") a direct route to professional football through their existing club pathway. Three-hundred-and-seventy-three Scottish youth soccer players (U11-U17) from three different playing standards (amateur, development, performance) completed a battery of commonly used generic field-based fitness tests (grip dynamometry, standing broad jump, countermovement vertical jump, 505 (505COD) and T-Drill (T-Test) change of direction and 10/20 m sprint tests) on two separate occasions within 7-14 days. The majority of field-based fitness tests selected within this study proved to be reliable measures of physical performance (ICC = 0.83-0.97; p < .01). However, COD tests showed weaker reliability in younger participants (ICC = 0.57-0.79; p < .01). The field-based fitness testing battery significantly discriminated between the unidentified and identified players; χ² (7) = 101.646, p < .001, with 70.2% of players being correctly classified. We have shown field-based fitness tests to be reliable measures of physical performance in youth soccer players. However, results from the 505COD and T-Test change of direction tests may be more variable in younger players, potentially due to complex demands of these tests and the limited training age established by these players. While the testing battery selected in this study was able to discriminate between unidentified and identified players, findings were inconsistent when attempting to differentiate between individual playing standards within the "identified" player group (development vs. performance).

Talent Identification in Sport: A Systematic Review

BACKGROUND

Talent identification (TID) programs are an integral part of the selection process for elite-level athletes. While many sport organizations utilize TID programs, there does not seem to be a clear set of variables that consistently predict future success.

OBJECTIVE

This review aims to synthesize longitudinal and retrospective studies examining differences between performance variables in highly skilled and less-skilled athletes in elite-level sport.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to identify relevant studies (N = 20).

RESULTS

There was a clear overrepresentation of studies that (1) examined physical profiles of athletes (60%); (2) focused on male samples (65%); (3) examined athletes between the ages of 10 and 20 years (60%); and (4) were published between the years 2010 and 2015 (65%). On closer examination, there was a high degree of variability in the factors that were found to discriminate between skilled and less-skilled individuals.

CONCLUSION

Findings from this review highlight how little is known about TID in elite sport and emphasize the need for greater diversity in TID research.

Development of Anaerobic Fitness in Top-Level Competitive Youth Ice Hockey Players

Leiter, JR, Cordingley, DM, and MacDonald, PB. Development of anaerobic fitness in top-level competitive youth ice hockey players. J Strength Cond Res 32(9): 2612-2615, 2018-Ice hockey is a physiologically complex sport involving both the anaerobic and aerobic energy systems. The purpose of this study was to evaluate the anaerobic power output (PO) of top-level competitive youth hockey players. It was hypothesized that with each successive increase in age, there would be an associated change in anaerobic PO. Two hundred and fifty-one male hockey players between the ages of 13-17 years participated in this study. All athletes completed a 30-second Wingate test as part of a preseason physiological and fitness combine. A 1-way analysis of variance was performed to compare peak PO (POpeak), average PO (POavg), and fatigue index between all age groups. A Tukey's post hoc test was used to determine changes in immediately successive age groups for all variables. Age categories were grouped as 13 years old (yrs) (n = 72), 14 yrs (n = 68), 15 yrs (57) and 16 yrs (n = 54, including 11 athletes 17 yrs). Absolute POpeak significantly increased with all age increases. Relative POpeak, absolute POavg, and relative POavg increased between the ages of 13 and 14 years, and 14 and 15 years, but not between the ages 15 and 16 years. There were no changes in fatigue index between any successive age groups. Anaerobic PO increases with an increase in age with no associated change in fatigue index. Athletes, coaches, and parents can use this normative data to help prepare the player for upcoming seasons in which there may be an increase in level or age class.

Genetic predictors of match performance in sub-elite Australian football players: A pilot study

The current study aimed to determine whether previously identified candidate polymorphisms were associated with match performance in sub-elite Australian Rules Football (ARF) players. The genotypes of thirty players were analysed along with 3x1-kilometre time trial results, ARF-specific skill assessments (handball and kicking), and match performance (direct game involvements) per minute (DGIs/min) to investigate if there was a relationship between any of the variables. Results support previous findings that aerobic time trials are a significant predictor of DGIs/min in sub-elite ARF players. Significant associations were found for genotypes ADRB2 CC (p = .001), PPARGC1A AA (p = .001), PPARGC1A AG (p < .001), ACE ID (p < .001), COMT AA (p = .003), BDNF AG (p = .008), ADRB1 CC (p = .018) and ADRB3 CC (p = .010) and the 3x1-kilometre time trials (p < .001). In the current study, a variant in the DRD2 gene was a strong predictor of handball possessions during a match. Significance was seen for variants in the BDNF and COMT genes when the kicking and handball skill test results were combined and used in a linear mixed model to predict DGIs/min, suggesting a potential relationship with motor learning. The confirmation of genetic predictors of player performance in a team sport, such as ARF, suggests a portion of the physiological mechanisms of skill and ARF-specific talent may be explained by the expression of a specific number of genes.

Psychological talent predictors in youth soccer: A systematic review of the prognostic relevance of psychomotor, perceptual-cognitive and personality-related factors

Within the multidimensional nature of soccer talent, recently there has been an increasing interest in psychological characteristics. The aim of this present research was to systematically review the predictive value of psychological talent predictors and provide better comprehension of the researchers’ methodological approaches and the empirical evidence for individual factors (i.e., psychomotor, perceptual-cognitive and personality-related). Results highlighted heterogeneous study designs (e.g., participants, measurement methods, statistical analyses) which may limit the comparability of studies’ findings. Analyzing the number of included studies, psychomotor (n = 10) and personality-related factors (n = 8) received more consideration within the literature than perceptual-cognitive factors (n = 4). In regard to empirical evidence, dribbling (0.47 ≤ d ≤ 1.24), ball control (0.57 ≤ d ≤ 1.28) and decision-making (d = 0.81) demonstrated good predictive values as well as the achievement motives hope for success (0.27 ≤ d ≤ 0.74) and fear of failure (0.21 ≤ d ≤ 0.30). In conclusion, there is growing acceptance of the need for more complex statistical analyses to predict future superior performance based on measures of current talent. New research addresses the necessity for large-scale studies that employ multidisciplinary test batteries to assess youth athletes at different age groups prospectively.

Correlation Between Upper Body Balance, Muscle Strength, and Power in Cricketers Belonging to Different Age Groups

Objective

The purpose of this study was to assess correlation between variables of upper body balance, muscular strength, and power in cricketers belonging to different age groups.

Methods

Forty-eight healthy male cricketers (26 adolescents aged 14-17 years and 22 adults aged 18-25 years) were recruited from Jamia Millia Islamia, New Delhi, India. After a warm-up, the participants underwent Upper Quarter Y Balance Test, backward overhead medicine ball throw test, and back-strength testing in a random order.

Results

Values of the Pearson correlation coefficient for muscle strength and upper body power were found to be 0.397 and 0.499 for adolescent and adult cricketers, respectively. Correlation coefficient values for upper body balance and strength range from -0.008 to 0.05 and 0.325 to 0.414 and for upper body balance and power range from 0.059 to 0.062 and 0.133 to 0.153 for adolescent and adult cricketers, respectively.

Conclusion

Statistically significant, moderate-sized correlations were demonstrated between muscular strength and upper body power in adolescent and adult cricketers. However, no correlations existed between upper body balance and power and upper body balance and muscular strength in these athletes.

Importance of Speed and Power in Elite Youth Soccer Depends on Maturation Status

Murtagh, CF, Brownlee, TE, O'Boyle, A, Morgans, R, Drust, B, and Erskine, RM. Importance of speed and power in elite youth soccer depends on maturation status. J Strength Cond Res 32(2): 297-303, 2018-Maturation status is a confounding factor when identifying talent in elite youth soccer players (ESP). By comparing performance of ESP and control participants (CON) matched for maturation status, the aims of our study were to establish the importance of acceleration, sprint, horizontal-forward jump, and vertical jump capabilities for determining elite soccer playing status at different stages of maturation. Elite youth soccer players (n = 213; age, 14.0 ± 3.5 years) and CON (n = 113; age, 15.0 ± 4.4 years) were grouped using years from/to predicted peak height velocity (PHV) to determine maturation status (ESP: pre-PHV, n = 100; mid-PHV, n = 25; post-PHV, n = 88; CON: pre-PHV, n = 44; mid-PHV, n = 15; post-PHV, n = 54). Participants performed 3 reps of 10- and 20-m sprint, bilateral vertical countermovement jump (BV CMJ), and bilateral horizontal-forward CMJ (BH CMJ). Elite youth soccer players demonstrated faster 10-m (p < 0.001) and 20-m sprint (p < 0.001) performance than CON at all stages of maturation. Mid-PHV and post-PHV ESP achieved greater BV CMJ height (p < 0.001) and BH CMJ distance (ESP vs. CON; mid-PHV: 164.32 ± 12.75 vs. 136.53 ± 21.96 cm; post-PHV: 197.57 ± 17.05 vs. 168.06 ± 18.50 cm; p < 0.001) compared with CON, but there was no difference in BV or BH CMJ between pre-PHV ESP and CON. Although 10 and 20 m and sprint performance may be determinants of elite soccer playing status at all stages of maturation, horizontal-forward and vertical jumping capabilities only discriminate ESP from CON participants at mid- and post-PHV. Our data therefore suggest that soccer talent identification protocols should include sprint, but not jump assessments in pre-PHV players.

Age and maturity related differences in motor coordination among male elite youth soccer players

This study investigated differences in generic and soccer specific motor coordination, as well as speed and agility depending on age and maturity in elite youth soccer players (U10-U15, N = 619). Measurements included body height, body weight and sitting height to estimate age at peak height velocity (APHV); three Körperkoordinationstest für Kinder subtests (i.e. jumping sideways (JS), moving sideways (MS), balancing backwards (BB)) to assess generic motor coordination; the UGent dribbling test for soccer specific motor coordination; a 5m/30m sprint and T-test for speed and agility, respectively. Age specific z-scores of the predicted APHV identified players as earlier, on time or later maturing. (M)ANOVA analyses showed significant age by maturity interaction effects for the speed and agility test cluster, revealing maturity related differences in U14 and U15 players. Next to an overall higher performance with age for all test clusters (η² 0.080-0.468), earlier maturing players outperformed their later maturing peers in 5m/30m sprinting. The opposite was seen for JS and BB. So, players' maturity status should be taken into account to adequately value performance in talent identification. Also, the focus on characteristics that appear to be minimally biased by an earlier maturational timing (i.e. motor coordination) should be increased.

Talent identification for soccer: Physiological aspects

OBJECTIVES

Soccer coaches are always looking to discover the next star player, without investing the necessary resources, time, and effort into a player's development. In the modern era, talent identification in soccer seems to be a comparative process rather than a developmental process. This article will look at the physiological profiles of soccer players in the modern era and how testing and talent identification processes should coincide with this data.

DESIGN

An extensive literature search identifying the physiological attributes of soccer players that are required to compete at an elite level was conducted. An examination of the methods to test these attributes was also conducted.

METHODS

Studies were assigned into three areas to understand the physiological aspect of soccer: physiological testing methods, benchmark values, and correlations between different tests.

RESULTS

A testing battery was established to test the key physiological attributes of prospective youth soccer players. Benchmark levels were also identified to allow coaches to understand areas of improvement.

CONCLUSIONS

Using a physiological testing battery will allow teams to track their players' progress throughout their developmental years. This allows coaches to consistently identify a player's strengths and weaknesses, as well as allow players who may experience late maturation to still be identified.

Anthropometric and Physical Performance of Youth Handball Players: The Role of the Relative Age

BACKGROUND

The relative age effect is essential throughout all of the talent selection processes in sports, especially during adolescence, which leaves fewer athletes within each cohort that are born late in the selected year. The aim of the present study was to examine the role of relative age in anthropometric and physical performance characteristics of youth handball players by gender.

METHODS

The sample that was selected included 47 participants (male n = 23, female n = 24). The data collection included anthropometric, body compositions parameters, and physical performance levels.

RESULTS

There was a significantly higher representation of players in the first semester in comparison with the second semester, for all of the gender groups, except for the selected male players. In males, statistically significant differences were found in height, sitting height, weight, wingspan, arm and leg circumferences, and in throws speed (in support and in suspension) between those players that were born in the first and second semester.

CONCLUSION

The results confirmed an effect of relative age in the players born in 2002 that were selected to participate in the Spanish Championship, which was different for males and females. In spite of this effect, which only appeared in females, significant differences in the anthropometric and physical conditions appeared in the male players.

When does the influence of maturation on anthropometric and physical fitness characteristics increase and subside?

The relationships between maturation and anthropometric and physical performance characteristics are dynamic and often asynchronous; confounding the capability to accurately evaluate performance during adolescence. This study aimed to (i) examine the influence of chronological age (CA) and somatic maturation (YPHV) upon anthropometric and physical performance parameters, and (ii) identify the transition/change time points in these relationships using segmental regression. N = 969 soccer players (8-18 years of age) completed anthropometric and physical test assessments, including a countermovement jump (CMJ), agility T test, 10 and 20 m sprints, and multistage fitness test (MSFT). When modeled against CA and YPHV, results identified time point phases with increased rates of stature (CA-7.5, YPHV-8.6 cm/y at 10.7-15.2 years or -3.2 to +0.8 YPHV) and body mass gain (CA-7.1, YPHV-7.5 kg/y at 11.9-16.1 years or -1.6 to +4.0 YPHV), followed by gain reductions. Increased rates of sprint performance development (31%-43% gains) occurred at 11.8-15.8 CA or -1.8 to +1.2 YPHV, with gains subsiding thereafter. CMJ, T test, and MSFT gains appeared relatively linear with no change in developmental rate apparent. Developmental tempos did again, however, subside at circa (CMJ and T test) to post-PHV (MSFT). Based on our sample and analysis, periods of increased developmental rates (stature, mass, sprint) were apparent alongside progressive gains for other physical measures, before all subsided at particular age and maturation time points. Findings highlight dynamic asynchronous development of players, physical attributes, and the need to account for the influence of maturation on athletic performance until post-PHV.

Improving the Prediction of Maturity From Anthropometric Variables Using a Maturity Ratio

PURPOSE

This study aimed to improve the prediction accuracy of age at peak height velocity (APHV) from anthropometric assessment using nonlinear models and a maturity ratio rather than a maturity offset.

METHODS

The dataset used to develop the original prediction equations was used to test a new prediction model, utilizing the maturity ratio and a polynomial prediction equation. This model was then applied to a sample of male youth academy soccer players (n = 1330) to validate the new model in youth athletes.

RESULTS

A new equation was developed to estimate APHV more accurately than the original model (new model: Akaike information criterion: -6062.1, R² = 90.82%; original model: Akaike information criterion = 3048.7, R² = 88.88%) within a general population of boys, particularly with relatively high/low APHVs. This study has also highlighted the successful application of the new model to estimate APHV using anthropometric variables in youth athletes, thereby supporting the use of this model in sports talent identification and development.

CONCLUSION

This study argues that this newly developed equation should become standard practice for the estimation of maturity from anthropometric variables in boys from both a general and an athletic population.

Relationships Between Measures of Physical Fitness Change When Age-Dependent Bias is Removed in a Group of Young Male Soccer Players

James, RS, Thake, CD, and Birch, SL. Relationships between measures of physical fitness change when age-dependent bias is removed in a group of young male soccer players. J Strength Cond Res 31(8): 2100-2109, 2017-Age-dependent bias is a key issue within talent identification of children, particularly when measures of physical fitness are used. Coaches in sport would benefit from a relatively straightforward method to remove age-dependent bias, enabling identification of children who are relatively high performers for their age. This study aimed to determine whether removal of age effects caused changes in the relationships between physical performance and anthropometric measures commonly used in talent identification and development systems. Sixty male soccer players, aged 11-17 years, underwent measures of anthropometry, muscular power, strength, sprint speed, and agility. Most absolute measures of performance were significantly correlated with each other, and all performance measures were significantly correlated with age. Age residuals were calculated, for all variables, to determine which players performed relatively well for their age and to investigate age-independent relationships between variables. In general, players with relatively fast sprint performance for their age were taller and had relatively high performance in jump power output and grip strength for their age (r > 0.25 and p < 0.025 in each case). Absolute sprint performance PC1 was significantly correlated with absolute agility performance PC1 (r = 0.473, p < 0.001). However, there was no significant relationship between age-independent measures of agility and any other measures. Usage of age residuals highlights performers that have relatively high physical fitness for their age. Such analyses may assist the talent identification and development processes as long as differential rates of physical development between players are also considered.

Relationships between anthropometric features, body composition, and anaerobic alactic power in elite post-pubertal and mature male taekwondo athletes

Purpose. The paper describes the relationships between anthropometric features, body composition, and anaerobic alactic power (AAP) in elite post-pubertal and mature male taekwondo athletes. Methods. The sample of 41 taekwondo athletes was divided into two groups: post-pubertal (P-P, n = 19, M

Can the ability to adapt to exercise be considered a talent-and if so, can we test for it?

Talent identification (TI) is a popular and hugely important topic within sports performance, with an ever-increasing amount of resources dedicated to unveiling the next sporting star. However, at present, most TI processes appear to select high-performing individuals at the present point in time, as opposed to identifying those individuals with the greatest capacity to improve. This represents a potential inefficiency within the TI process, reducing its effectiveness. In this article, we discuss whether the ability to adapt favorably, and with a large magnitude, to physical training can be considered a talent, testing it against proposed criteria. We also discuss whether, if such an ability can be considered a talent, being able to test for it as part of the TI process would be advantageous. Given that such a capacity is partially heritable, driven by genetic variation between individuals that mediate the adaptive response, we also explore whether the information gained from genetic profiling can be used to identify those with the greatest capacity to improve. Although there are some ethical hurdles which must be considered, the use of genetic information to identify those individuals with the greatest capacity appears to hold promise and may improve both the efficiency and effectiveness of contemporary TI programmes.

Equity of Physical Characteristics Between Adolescent Males and Females Participating in Single- or Mixed-Sex Sport

Krause, LM, Naughton, GA, Benson, AC, and Tibbert, S. Equity of physical characteristics between adolescent males and females participating in single- or mixed-sex sport. J Strength Cond Res 32(5): 1415-1421, 2018-Policies on single- or mixed-sex junior sports participation continue to be challenged publically and legally. Often challenges relate to perceptions of size and performance variability between adolescent males and females, yet the evidence base behind these challenges lacks recent review and rigor. Physical performance was compared between males and females from 2 groups of younger (<13 years, n = 109, 67% females, 33% males) and older (≥13 years, n = 108, 43% females, 57% males) adolescents. Using a cross-sectional design, adolescents were tested for speed, strength, power, and endurance. No sex differences were found for most of the physical test results in the <13 years age group, although males showed greater endurance (p = 0.020) and upper-body strength (p = 0.010) than females. However, among adolescents aged ≥13 years, males scored better than females in all physical tests, without exception (p > 0.05). Further explorations comparing how many females in the same age grouping shared test results equal to or greater than the top third of males were fewer in the older than younger age group. Equality of participation in mixed-sex sport becomes more difficult to guarantee for older adolescents when results from generic sport-related physical test performances are considered.

Differences in Physical Capacity Between Junior and Senior Australian Footballers

Kelly, SJ, Watsford, ML, Austin, DJ, Spurrs, RW, Pine, MJ, and Rennie, MJ. Differences in physical capacity between junior and senior Australian footballers. J Strength Cond Res 31(11): 3059-3066, 2017-The purpose of this study was to profile and compare anthropometric and physical capacities within elite junior and senior Australian football (AF) players of various chronological ages and stages of athletic development. Seventy-nine players, including junior and senior AF players from one professional club, were profiled using 11 assessments. Junior players were divided into 2 groups based on chronological age (under 16 and 18 years) and senior players according to years since drafted to a professional AF team (1-2 years, 3-7 years, and 8+ years). Parametric data were assessed using a 1-way analysis of variance (ANOVA), whereas nonparametric data were assessed using a Kruskal-Wallis ANOVA. The magnitude difference between players was measured using the Hopkins' effect size (ES). Significant differences were evident between under-16 players and all senior player groups for anthropometric (p = 0.001-0.019/ES = 1.25-2.13), absolute strength (p = 0.001-0.01/ES = 1.82-4.46), and relative strength (p = 0.001-0.027/ES = 0.84-3.55). The under-18 players displayed significantly lower absolute strength (p = 0.001-0.012/ES = 1.82-3.79) and relative strength (p = 0.001-0.027/ES = 0.85-4.00) compared with the 3-7 and 8+ players. Significant differences were evident between the under-16 players and senior player groups for explosive jumping and throwing tests (p = 0.001-0.017/ES = 1.03-2.99). Minimal differences were evident between all player groups for running assessments; however, the under-16 players were significantly slower compared with the 8+ players for the 3-km time trial (p < 0.02/ES = 1.31), whereas both junior player groups covered significantly less distance during the Yo-Yo IR2 (p < 0.02/ES = 1.19 and 1.60). Results of this study display a significant deficit in strength between junior and senior AF players.

SELECTION OF TALENTS IN HANDBALL: ANTHROPOMETRIC AND PERFORMANCE ANALYSIS

ABSTRACT Introduction: Anthropometric and physical performance parameters that determine competitive levels in handball need to be carefully studied to identify which of them can bring the optimal contribution when the talents for this sport are selected. Objective: To identify which anthropometric and physical performance variables evaluated in the basic categories (infantile, under-15 and cadet, under-17) have the greatest influence on professional levels attained by male and female handball players throughout their sports careers. Method: A total of 145 handball players (75 males and 70 females) participated in the study. Participants were initially evaluated during the season 1998-99 and their performance levels were supervised until March 2013. The resulting data were classified according to the performance level (regional n = 109; national n = 36), gender, and category (infantile, cadet). Results: The MANCOVA analysis indicated that the player’s maturation stage is one of the main parameters to be accounted for when selecting the variables that should configure a talent detection model for handball, which is also conditioned by sex. Anthropometric variables are highly influential in the case of male players, while physical performance variables (squat jump, counter movement jump, counter movement jump with arm, 10x5m shuttle run, 20 m shuttle run, and VO2 max) have a similar effect in males and females. Conclusion: The study of changes occurring in anthropometric and physical performance variables may yield useful information to detect talents in handball, and maturation is a key factor to choose the most appropriate variables.

Identifying the physical and anthropometric qualities explanatory of paddling adolescents

OBJECTIVES

This study aimed to identify the physical and/or anthropometric qualities explanatory of adolescent surf lifesavers participating in paddling activities.

DESIGN

Cross-sectional observational study.

METHODS

A total of 53 (14-18years) male participants were recruited and classified into two groups; paddlers (n=30; actively participating in paddling), non-paddlers (n=23; not actively participating in paddling). All participants completed a testing battery that consisted of 16 physical (isometric strength and muscular endurance) and anthropometric (height, mass, segment lengths and breadths) assessments. Binary logistic regression models and receiver operating characteristic curves were built to identify the physical and/or anthropometric qualities most explanatory of paddling status (two levels: 1=paddlers, 0=non-paddlers).

RESULTS

Significant between group differences were noted for 14 of the 16 assessments (P<0.05; d=0.59-1.29). However, it was the combination of horizontal shoulder abduction isometric strength, body mass, and sitting height that provided the greatest association with paddling status (Akaike Information Criterion=47.13). This full model successfully detected 87% and 70% of the paddlers and non-paddlers, respectively, with an area under the curve of 84.2%.

CONCLUSIONS

These results indicate that there are distinctive physical and anthropometric qualities that may be advantageous for prospective paddling athletes to possess. Practitioners should integrate assessments of horizontal shoulder abduction isometric strength, body mass, and sitting height, as well as their subsequent cut-off thresholds, into talent detection programs focused toward the recognition of performance potential in paddling-oriented sports.

Validity and usefulness of the Line Drill test for adolescent basketball players: a Bayesian multilevel analysis

The study examined the validity of the Line Drill test (LD) in male adolescent basketball players (10-15 years). Sensitiveness of the LD to changes in performance across a training and competition season (4 months) was also considered. Age, maturation, body size and LD were measured (n = 57). Sensitiveness of the LD was examined pre- and post-competitive season in a sub-sample (n = 44). The time at each of the four shuttle sprints of the LD (i.e. four stages) was modelled with Bayesian multilevel models. We observed very large correlation of performance at stage 4 (full LD protocol) with stage 3, but lower correlations with the early LD stages. Players' performance by somatic maturity differed substantially only when considering full LD protocol performance. Substantial improvements in all stages of the protocol were observed across the 4-month competitive season. The LD protocol should be shortened by the last full court shuttle sprint, remaining sensitive to training exposure, and independent of maturity status and body size.

National Strength and Conditioning Association Position Statement on Long-Term Athletic Development

There has recently been a growing interest in long-term athletic development for youth. Because of their unique physical, psychological, and social differences, children and adolescents should engage in appropriately prescribed exercise programs that promote physical development to prevent injury and enhance fitness behaviors that can be retained later in life. Irrespective of whether a child is involved in organized sport or engages in recreational physical activity, there remains a need to adopt a structured, logical, and evidence-based approach to the long-term development of athleticism. This is of particular importance considering the alarmingly high number of youth who fail to meet global physical activity recommendations and consequently present with negative health profiles. However, appropriate exercise prescription is also crucial for those young athletes who are physically underprepared and at risk of overuse injury because of high volumes of competition and an absence of preparatory conditioning. Whether the child accumulates insufficient or excessive amounts of exercise, or falls somewhere between these opposing ends of the spectrum, it is generally accepted that the young bodies of modern day youth are often ill-prepared to tolerate the rigors of sports or physical activity. All youth should engage in regular physical activity and thus should be viewed as "athletes" and afforded the opportunity to enhance athleticism in an individualized, holistic, and child-centered manner. Because of emerging interest in long-term athletic development, an authorship team was tasked on behalf of the National Strength and Conditioning Association (NSCA) to critically synthesize existing literature and current practices within the field and to compose a relevant position statement. This document was subsequently reviewed and formally ratified by the NSCA Board of Directors. A list of 10 pillars of successful long-term athletic development are presented, which summarize the key recommendations detailed within the position statement. With these pillars in place, it is believed that the NSCA can (a) help foster a more unified and holistic approach to long-term athletic development, (b) promote the benefits of a lifetime of healthy physical activity, and

VARIABILIDADE DO DESEMPENHO NO LINE-DRILL TEST EM ADOLESCENTES JOGADORES DE BASQUETEBOL

RESUMO Introdução: A prática de basquetebol durante a adolescência aumenta o tamanho corporal e o desempenho funcional. O basquetebol envolve esforços máximos de curta duração com mudanças de direção que utilizam o metabolismo anaeróbico e a agilidade. Objetivo: Examinar a variação do desempenho no Line-drill Test em adolescentes jogadores de basquetebol (n = 59, faixa etária 9 a 15 anos) com relação ao estado de maturação somática (idade estimada do pico da velocidade de crescimento [PVC]) e à variação do tamanho corporal. Métodos: Foi considerada a idade cronológica, o tempo previsto para a idade do PVC pelo protocolo maturity offset, a estatura e a massa corporal medidas por antropometria e o desempenho no Line-drill Test. Foram utilizados modelos alométricos proporcionais para controlar a variação associada ao tamanho corporal, idade cronológica e estado de maturação na variação interindividual no Line-drill Test. Resultados: Observou-se uma relação linear negativa elevada entre o desempenho no Line-drill Test e a idade cronológica (r = - 0,64, IC 95% -0,77 a -0,46, p < 0,01). A relação entre o desempenho no Line-drill Test e o tempo até a idade do PVC mostrou ser não linear, indicando desaceleração na variação do desempenho, aproximadamente entre a idade do PVC e um ano após o PVC predito. Os modelos alométricos mostraram uma relação negativa entre o tamanho corporal e o desempenho no Line-drill Test. A amplitude da variância explicada nos modelos alométricos proporcionais foi de 0,28 a 0,48. Foram observados expoentes negativos de pequena magnitude para a idade cronológica e para o indicador de maturação, sendo, porém, significativos e de amplitude reduzida (-0,05 a -0,06). Conclusão: A utilização de modelos alométricos para controlar a influência do tamanho corporal tem o potencial de ajudar a compreender o desenvolvimento dos desempenhos de agilidade durante a adolescência em jogadores de basquetebol.

A comparison of the physical and anthropometric qualities explanatory of talent in the elite junior Australian football development pathway

OBJECTIVES

To compare the physical and anthropometric qualities explanatory of talent at two developmental levels in junior Australian football (AF).

DESIGN

Cross-sectional observational.

METHODS

From a total of 134 juniors, two developmental levels were categorised; U16 (n=50; 15.6±0.3 y), U18 (n=84; 17.4±0.5 y). Within these levels, two groups were a priori defined; talent identified (U16; n=25; 15.7±0.2 y; U18 n=42; 17.5±0.4 y), non-talent identified (U16; n=25; 15.6±0.4 y; U18; n=42; 17.3±0.6 y). Players completed seven physical and anthropometric assessments commonly utilised for talent identification in AF. Binary logistic regression models were built to identify the qualities most explanatory of talent at each level.

RESULTS

A combination of standing height, dominant leg dynamic vertical jump height and 20m sprint time provided the most parsimonious explanation of talent at the U16 level (AICc=60.05). At the U18 level, it was a combination of body mass and 20m sprint time that provided the most parsimonious explanation of talent (AICc=111.27).

CONCLUSIONS

Despite similarities, there appears to be distinctive differences in physical and anthropometric qualities explanatory of talent at the U16 and U18 level. Coaches may view physical and anthropometric qualities more (or less) favourably at different levels of the AF developmental pathway. Given these results, future work should implement a longitudinal design, as physical and/or anthropometric qualities may deteriorate (or emerge) as junior AF players develop.

Physical characteristics of elite adolescent female basketball players and their relationship to match performance

There were two aims of this study: first, to investigate physical fitness and match performance differences between under-16 (U16) and under-18 (U18) female basketball players, and second, to evaluate the relationship between physical fitness and game-related performances. Twenty-three young, female, elite Spanish basketball players (16.2 1.2 years) participated in the study. The sample was divided into two groups: U16 and U18 players. The average scores from pre- and post-season physical fitness measurements were used for subsequent analyses. Anthropometric variables were also measured. To evaluate game performance, game-related statistics, including the number of games and minutes played, points, rebounds, assists, steals and blocks per game, were recorded for every competitive match in one season. When anthropometric and physical performance variables were compared between groups, the U18 group demonstrated significantly (p<0.05) higher values in upper (+21.2%) and lower (+27.11%) limb strength compared to the U16 group. Furthermore, no significant differences between groups were observed in match performance outcomes. Only two performance variables, steals and assists per game, correlated significantly with jump capacity, speed, agility, anaerobic power, repeated sprint ability and aerobic power (p ≤ 0.005). These findings can help optimize training programs for young, elite female basketball players.

Biological maturity-associated variance in peak power output and momentum in academy rugby union players

The study aimed to evaluate the mediating effect of biological maturation on anthropometrical measurements, performance indicators and subsequent selection in a group of academy rugby union players. Fifty-one male players 14-17 years of age were assessed for height, weight and BMI, and percentage of predicted mature status attained at the time of observation was used as an indicator of maturity status. Following this, initial sprint velocity (ISV), Wattbike peak power output (PPO) and initial sprint momentum (ISM) were assessed. A bias towards on-time (n = 44) and early (n = 7) maturers was evident in the total sample and magnified with age cohort. Relative to UK reference values, weight and height were above the 90th and 75th centiles, respectively. Significant (p ≤ .01) correlations were observed between maturity status and BMI (r = .48), weight (r = .63) and height (r = .48). Regression analysis (controlling for age) revealed that maturity status and height explained 68% of ISM variance; however, including BMI in the model attenuated the influence of maturity status below statistical significance (p = .72). Height and BMI explained 51% of PPO variance, while no initial significant predictors were identified for ISV. The sample consisted of players who were on-time and early in maturation with no late maturers represented. This was attributable, in part, to the mediating effect of maturation on body size, which, in turn, predicted performance variables.

The Great British Medalists Project: A Review of Current Knowledge on the Development of the World's Best Sporting Talent

The literature base regarding the development of sporting talent is extensive, and includes empirical articles, reviews, position papers, academic books, governing body documents, popular books, unpublished theses and anecdotal evidence, and contains numerous models of talent development. With such a varied body of work, the task for researchers, practitioners and policy makers of generating a clear understanding of what is known and what is thought to be true regarding the development of sporting talent is particularly challenging. Drawing on a wide array of expertise, we address this challenge by avoiding adherence to any specific model or area and by providing a reasoned review across three key overarching topics: (a) the performer; (b) the environment; and (c) practice and training. Within each topic sub-section, we review and calibrate evidence by performance level of the samples. We then conclude each sub-section with a brief summary, a rating of the quality of evidence, a recommendation for practice and suggestions for future research. These serve to highlight both our current level of understanding and our level of confidence in providing practice recommendations, but also point to a need for future studies that could offer evidence regarding the complex interactions that almost certainly exist across domains.

Sprint and jump performances do not determine the promotion to professional elite soccer in Spain, 1994-2012

The aims of this study are (a) to describe the evolution of neuromuscular performance over an 18 year period within a Spanish elite reserve team; (b) to check if there were any relation between the playing position and sprint and jump performances and (c) to look into the alleged impact of this factor on the top playing level attained by the soccer players. We considered the physical tests (5 m and 15 m sprint times and countermovement jump (CMJ) height) made by 235 players enrolled in the reserve team of the Club from 1994 to 2012 and the highest competitive-level they achieved: Spanish first (n = 39) and second divisions (n = 36) and semi-professional (n = 160). Furthermore, the players were classified according to their playing positions. The main findings were a very-likely/most-likely lower neuromuscular performance (ES = 0.48-0.68, small to moderate) in the last six-season term (2006-2012) than in the first term (1994-2000); possibly/very-likely lower performances in sprinting and CMJ (ES = 0.22-0.55, small) by central defenders (CDs) and midfielders than by other playing positions; very-likely better performances in sprinting and jumping by first and second divisions central defenders than by semi-professional central defenders (ES = 0.90-1.02, moderate). Sprint and jump performances are not a relevant physical parameter to promote to the top level of soccer in Spain except for one in six of the playing positions: CDs.

The application of a multi-dimensional assessment approach to talent identification in Australian football

This study investigated whether a multi-dimensional assessment could assist with talent identification in junior Australian football (AF). Participants were recruited from an elite under 18 (U18) AF competition and classified into two groups; talent identified (State U18 Academy representatives; n = 42; 17.6 ± 0.4 y) and non-talent identified (non-State U18 Academy representatives; n = 42; 17.4 ± 0.5 y). Both groups completed a multi-dimensional assessment, which consisted of physical (standing height, dynamic vertical jump height and 20 m multistage fitness test), technical (kicking and handballing tests) and perceptual-cognitive (video decision-making task) performance outcome tests. A multivariate analysis of variance tested the main effect of status on the test criterions, whilst a receiver operating characteristic curve assessed the discrimination provided from the full assessment. The talent identified players outperformed their non-talent identified peers in each test (P < 0.05). The receiver operating characteristic curve reflected near perfect discrimination (AUC = 95.4%), correctly classifying 95% and 86% of the talent identified and non-talent identified participants, respectively. When compared to single assessment approaches, this multi-dimensional assessment reflects a more comprehensive means of talent identification in AF. This study further highlights the importance of assessing multi-dimensional performance qualities when identifying talented team sports.

A retrospective study on anthropometrical, physical fitness, and motor coordination characteristics that influence dropout, contract status, and first-team playing time in high-level soccer players aged eight to eighteen years

The goal of this article was twofold, and a 2-study approach was conducted. The first study aimed to expose the anthropometrical, physical performance, and motor coordination characteristics that influence dropout from a high-level soccer training program in players aged 8-16 years. The mixed-longitudinal sample included 388 Belgian youth soccer players who were assigned to either a "club group" or a "dropout group." In the second study, cross-sectional data of anthropometry, physical performance, and motor coordination were retrospectively explored to investigate which characteristics influence future contract status (contract vs. no contract group) and first-team playing time for 72 high-level youth soccer players (mean age = 16.2 years). Generally, club players outperformed their dropout peers for motor coordination, soccer-specific aerobic endurance, and speed. Anthropometry and estimated maturity status did not discriminate between club and dropout players. Contract players jumped further (p = 0.011) and had faster times for a 5-m sprint (p = 0.041) than no contract players. The following prediction equation explains 16.7% of the variance in future playing minutes in adolescent youth male soccer players: -2,869.3 + 14.6 × standing broad jump. Practitioners should include the evaluation of motor coordination, aerobic endurance, and speed performances to distinguish high-level soccer players further succeeding a talent development program and future dropout players, between 8 and 16 years. From the age of 16 years, measures of explosivity are supportive when selecting players into a future professional soccer career.

Relative age effect: implications for effective practice

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.

The biological age of 14-year-old boys and success in adult soccer: do early maturers predominate in the top-level game?

Talent identification and development in soccer is often biased by maturation-related differences of young athletes. However, there is no information available about success rates for youth maturing at different tempos to achieve success in elite adult soccer. The purposes of this study were to determine the prevalence of different maturational groups among boys playing soccer, and to track them for competence in adult performance. A prospective cohort study design was used to follow 55, 14-year-old boys playing in Serbian youth soccer Division I over eight years. At the age of 14, biological age using skeletal age rates was determined, and participants were categorized as early maturers (EaM), normal maturers (NoM), and late maturers (LaM). Game competence for adult soccer at age 22 was described as elite if an individual played for clubs competing in top-five international soccer leagues (La Liga, Premier League, Bundesliga, Serie A, and Ligue 1), and/or has become a member of an adult National team. Among boys in our study group, 43.8% were categorized as EaM, 35.4% as NoM, and 20.8% as LaM (P = 0.11). A significant difference in biological age was found among maturational groups at age 14, with EaM > NoM > LaM (P > 0.0001). When assessed for adult soccer competence, 33.3% of participants (16 out of 48 players) succeed in achieving elite level. Elite soccer competence acquired 60.1% players from the group of LaM, 38.1% from NoM, and 11.8% from EaM (P > 0.0001). Our comparative analysis suggests that soccer excludes early maturing boys and favors late maturing boys as level of performance increases.