Prediction of sports talent in young throwers using machine learning / Predicción del talento deportivo en jóvenes lanzadores utilizando machine learning

The objective of this study is to detect any performance factors in athletics throws between 1997 and 2015 in 662 throwers (15.67 ± 1.01 years of the National Program for Sports Technification of the Royal Spanish Athletics Federation using Machine Learning methods by means of algorithms (Logistic Regression, Random Forest and XG Boost). When examining the importance of the variables with reference to performance, the triple jump (0.20) stands out over the rest of the variables: backward overhead shot throw (0.14), arm span (0.11), vertical jump (0.10), body mass (0.20), height (0.07) and flexibility (0.03). In each discipline the triple jump takes the lead in shot put (0.20), discus (0.21) and hammer (0.29) throws, while backward overhead shot throw does in javelin, the variables rearranging themselves in a particular way depending on the discipline. These findings enable the early detection of potential talents as well as their subsequent sport specialization (AU)

El estudio aborda la detección de factores de rendimiento en los lanzamientos atléticos utilizando técnicas de Machine Learning, en 662 lanzadores (15,67 ± 1,01 años) del Programa Nacional de Tecnificación Deportiva de la Real Federación Española de Atletismo entre 1997 y 2015, mediante diferentes algoritmos (Logistic Regression, Random Forest y XGBoost). Al medir la importancia de las variables en función del rendimiento, el triple salto (0,20) destaca sobre el resto de variables: lanzamiento dorsal (0,14), envergadura (0,11), salto vertical (0,10), masa corporal, estatura (0,07) y flexibilidad (0,03). En cada disciplina, el triple salto encabeza la importancia en los lanzamientos de peso (0,20), disco (0,21) y martillo (0,29), mientras que el lanzamiento dorsal lo hace en la jabalina (0,20). Las variables se reordenande forma particular modificando su importancia para cada disciplina. Estos hallazgos permiten mejorar la detección inicial de posibles talentos, así como su posterior especialización deportiva (AU)

Energy cost differences between marathon runners and soccer players: Constant versus shuttle running.

Purpose: In the last decades, the energy cost assessment provided new insight on shuttle or constant running as training modalities. No study, though, quantified the benefit of constant/shuttle running in soccer-players and runners. Therefore, the aim of this study was to clarify if marathon runners and soccer players present specific energy cost values related to their training experience performing constant and shuttle running. Methods: To this aim, eight runners (age 34 ± 7.30y; training experience 5.70 ± 0.84y) and eight soccer-players (age 18.38 ± 0.52y; training experience 5.75 ± 1.84y) were assessed randomly for 6' on shuttle-running or constant-running with 3 days of recovery in-between. For each condition, the blood lactate (BL) and the energy cost of constant (Cr) and shuttle running (CSh) was determined. To assess differences for metabolic demand in terms of Cr, CSh and BL over the two running conditions on the two groups a MANOVA was used. Results: V·O2max were 67.9 ± 4.5 and 56.8 ± 4.3 ml·min-1 kg-1 (p = 0.0002) for marathon runners and soccer players, respectively. On constant running, the runners had a lower Cr compared to soccer players (3.86 ± 0.16 J kg-1m-1 vs. 4.19 ± 0.26 J kg-1 m-1; F = 9.759, respectively; p = 0.007). On shuttle running, runners had a higher CSh compared to soccer players (8.66 ± 0.60 J kg-1 m-1 vs. 7.86 ± 0.51 J kg-1 m-1; F = 8.282, respectively; with p = 0.012). BL on constant running was lower in runners compared to soccer players (1.06 ± 0.07 mmol L-1 vs. 1.56 ± 0.42 mmol L-1, respectively; with p = 0.005). Conversely, BL on shuttle running was higher in runners compared to soccer players 7.99 ± 1.49 mmol L-1 vs. 6.04 ± 1.69 mmol L-1, respectively; with p = 0.028). Conclusion: The energy cost optimization on constant or shuttle running is strictly related to the sport practiced.

A idade relativa influencia na pontuação do ranking de triatletas juniores brasileiros? / Does relative age influence the ranking of brazilian junior triathletes?

O efeito da idade relativa (EIR) se refere a diferença na idade cronológica entre os quartis de nascimento dos atletas da mesma faixa etária, que pode beneficiar pessoas nascidas no início do ano. Este fenômeno está claro em diversos esportes coletivos, porem em modalidades individuais os resultados ainda são inconsistentes, principalmente no triathlon. Sendo assim, nos objetivamos analisar se o efeito da idade relativa influencia no ranking brasileiro de triathlon em atletas juniores da categoria 16/17 e 18/19. A amostra do estudo foi composta por triatletas do sexo masculino da categoria 16/17 (N=132) e 18/19 (N=164), que compuseram os rankings dos anos de 2011 a 2019. Para comparação e análise dos dados foi identificado o quartil de cada atleta, assim como, os dados referentes as pontuações do ranking. Para testar o efeito da idade relativa, foi realizado o teste de qui-quadrado (χ2 ). Em seguida testamos a normalidade com o teste de kolmogorov-smirnov. Foi realizado o teste de kruskal wallis para verificar diferenças entre os quartis em relação aos pontos do ranking e adotamos nível de significância de p≤0,05 para todos os testes. Os resultados mostraram não haver diferenças significativa na distribuição no quartil dos atletas em ambas as categorias. Além disso, evidenciamos também que não houve influência desse fenômeno nas pontuações dos rankings. Com isso, podemos concluir que o EIR está ausente em triatletas juniores brasileiros e que este fenômeno não influencia nas pontuações dos rankings.(AU)

The relative age effect (RAE) refers to the difference in chronological age between birth quarters of athletes of the same age group, who may benefit people born at the beginning of the year. This phenomenon is clear in several collective sports, but in individual modalities, the results are still inconsistent, especially in triathlon. Thus, we aim to analyze if the effect of relative age influences the Brazilian triathlon ranking in junior athletes of the category 16/17 and 18/19. The study sample consisted of male triathletes of the 16/17 (N = 132) and 18/19 (N = 164) males, who composed the rankings of the years 2011 to 2019. For comparison and analysis of the data was identified the quartile of each athlete, as well as the data referring to the scores of the ranking. To test the effect of relative age, the chi-square test (χ 2 ) was performed. Then we test normality with the kolmogorov-smirnov test. We performed the kruskal wallis test to verify differences between the quartiles in relation to the ranking points and adopted a significance level of p≤0.05 for all the tests. The results showed that there were no significant differences in the quartile distribution of athletes in both categories. In addition, we also showed that there was no influence of this phenomenon on the rankings scores. With this, we can conclude that the RAE is absent in Brazilian junior triathletes and that this phenomenon does not influence the rankings scores.(AU)

Factors affecting sports involvement in a school-based youth cohort: Implications for long-term athletic development.

The aim of the present study was to determine the factors affecting sports involvement in a school-based adolescent population. The cross-sectional cohort study assessed anthropometry, physical capacities and motor competence in 501 boys (aged 10-16 y), from junior (10-12 y) and senior (13-16 y) cohorts. Sports participation data was collected from junior participants. Multivariate analysis of covariance revealed moderate maturity, anthropometry, physical capacity and motor competence differences between sports in the senior cohort (F = 2.616, p < 0.001, η2 = .08), but not in the junior cohort. Furthermore, differences in physical fitness were revealed between playing levels (F = 2.616, p < 0.001, η2 = .08), with a discriminant analysis correctly classifying 73% of participants using aerobic fitness and vertical jump measures. Representative level participants engaged in more structured training and commenced organised competition at a later age (F = 4.332, p < 0.001, η2 = .21). This study's findings are twofold: 1) physical and motor competence profiles differ more between sports with increasing age, and 2) participants at a higher level of competition report delayed engagement in their main sport. As a result, schools may be the ideal environment in which to provide children and adolescents with the opportunity to sample different sports.

Seleção em ginástica artística feminina no Brasil / Women artistic gymnastics selection in Brazil / Selección de gimnasia artística femenina de Brasil

Resumo O estudo aborda procedimentos adotados por 40 treinadores na detecção e seleção de ginastas e caracteriza clubes brasileiros que têm programas de seleção (PS). Em 70% dos casos o treinador é responsável pela tomada de decisão na detecção; 90% usam testes motores (técnico-específicos, velocidade, força e flexibilidade). O método misto é o mais usado (55%), contém dados antropométricos, motores e técnicos (70,0%, 62,5%, 47,5%, respectivamente). A maioria dos clubes (61,5%) faz recrutamento periódico; 38,5% usam a forma externa de divulgação. Apenas oito clubes (30,8%) têm PS e esses têm 30% das ginastas de elite.

Abstract This study investigates coaches' (n = 40) procedures in gymnastics selection, and characterizes detection and selection programs (PS) implemented in Brazilian clubs. In 70% of the cases, the coach is the main decision maker; 90% uses motor tests (specific motor skills, speed, strength and flexibility) in PS. The mixed method is the most often used (55%) and comprises anthropometric, motor and technical data (70.0%, 62.5%, 47.5%, respectively). Most clubs (61.5%) conduct periodic recruitment; 38.5% use an external form. Only 8 clubs (30.8%) have PS, and these have 30% of elite gymnasts.

Resumen El presente estudio aborda los procedimientos empleados por 40 entrenadores de la selección de gimnasia y describe los clubes brasileños que cuentan con programas de selección (PS). En el 70% de los casos, el entrenador es el responsable de la toma de decisiones en la detección de las gimnastas; el 90% utiliza pruebas motoras (técnico-específicas, velocidad, fuerza y flexibilidad). El método mixto es el más utilizado (55%) e incluye datos antropométricos, motores y técnicos (70,0; 62,5, y 47,5%, respectivamente). La mayoría de los clubes (61,5%) realizan reclutamientos de manera periódica; el 38,5% de ellos lo hace de manera externa. Solo 8 clubes (30,8%) tienen PS y estos cuentan con el 30% de las gimnastas de élite.

Generic anthropometric and performance characteristics among elite adolescent boys in nine different sports.

The aim of the present study was to evaluate the Flemish Sports Compass (FSC), a non-sport-specific generic testing battery. It was hypothesised that a set of 22 tests would have sufficient discriminant power to allocate athletes to their own sport based on a unique combination of test scores. First, discriminant analyses were applied to the 22 tests of anthropometry, physical fitness and motor coordination in 141 boys under age 18 (16.1 ± 0.8 years) and post age at peak height velocity (maturity offset = 2.674 ± 0.926) from Flemish Top Sport Academies for badminton, basketball, gymnastics, handball, judo, soccer, table tennis, triathlon and volleyball. Second, nine sequential discriminant analyses were used to assess the ability of a set of relevant performance characteristics classifying participants and non-participants for the respective sports. Discriminant analyses resulted in a 96.4% correct classification of all participants for the nine different sports. When focusing on relevant performance characteristics, 80.1% to 97.2% of the total test sample was classified correctly within their respective disciplines. The discriminating characteristics were briefly the following: flexibility in gymnastics, explosive lower-limb strength in badminton and volleyball, speed and agility in badminton, judo, soccer and volleyball, upper-body strength in badminton, basketball and gymnastics, cardiorespiratory endurance in triathletes, dribbling skills in handball, basketball and soccer and overhead-throwing skills in badminton and volleyball. The generic talent characteristics of the FSC enable the distinction of adolescent boys according to their particular sport. Implications for talent programmes are discussed.

Detecção e seleção de talentos na ginástica artística feminina: a perspectiva dos técnicos brasileiros / Talent detection and selection in women's artistic gymnastics: the Brazilian coaches' perspective / Detección y selección de talentos en gimnasia artística femenina: la perspectiva de los entrenadores de Brasil

Este artigo tem por objetivo apresentar e discutir a detecção e a seleção de talentos na Ginástica Artística Feminina com enfoque para os aspectos que norteiam as condutas dos técnicos brasileiros. Entrevistamos 34 técnicos de 29 instituições distribuídas no Brasil. Observamos que os meios utilizados para detectar e selecionar os talentos na modalidade privilegiam a idade de ingresso, as características antropométricas e os testes físico-motores. Porém, sabemos que os determinantes do sucesso no esporte são multifatoriais e, por vezes, as avaliações transversais utilizadas não contemplam todos os fatores que contribuem para a obtenção de bons resultados no alto rendimento.

La investigación aspiró a presentar y discutir la detección y selección de talentos en Gimnasia Artística femenina centrándose en los aspectos que guían la conducta de los entrenadores brasileños. Hemos entrevistado a 34 entrenadores de 29 instituciones distribuidas en Brasil. Los resultados indican que los medios utilizados para detectar y seleccionar talentos priorizan la edad de ingreso, evaluaciones antropométricas y pruebas físico-motoras. Pero sabemos que los determinantes del éxito en el deporte son multifactoriales y, a veces, las evaluaciones transversales utilizadas no contemplan todos los factores que contribuyen a los buenos resultados en el alto rendimiento.

The aim of this article is to present and discuss the talent detection and selection in Women's Artistic Gymnastics considering the aspects that guide these procedures in Brazil. We conducted a field based study and we interviewed 34 coaches from 29 institutions. We find out that the methods used to detect and select talents in Women's Artistic Gymnastics prioritize the initiation age of practice, the anthropometrics characteristics and the physical-motor tests. However, it is known that the determinant factors for success in sports are multifactorial and sometimes the transversal tests used in the assessment can't cover all aspects that have impact on the successful career at sport high level.

Influência do tempo de reação simples na seleção de jovens talentos no tênis / Simple reaction time applied for selecting young talents in tennis

Este estudo objetivou apresentar a importância dos tempos de reação simples, cognitivo e motor, na seleção de talentos para o tênis. Participaram 240 jovens de seis a 13 anos (9,61 ±1,64), de ambos os sexos. Os voluntários foram submetidos e aprovados, na primeira fase do estudo, em um teste de habilidades específicas da modalidade (ITN). Na segunda fase, foram submetidos a um teste de tempo de reação simples. Foi realizada Ancova para identificar diferenças no ITN tendo o tempo de reação como variável independente e idade como covariável. Os resultados mostraram que houve diferença para o ITN entre os grupos de tempo de reação cognitivo ajustado para a idade (p=0,04) e não houve diferença entre as médias de ITN quando se comparou o tempo de reação motor (p=0,162). Conclui-se que o tempo de reação cognitivo é uma variável importante no processo de detecção de talentos em tênis.

The present study aimed at presenting the importance of simple reaction times, both cognitive and motor, in selecting potential talents in tennis players. Two hundred and forty young people participated in the study, from six to thirteen years old, of both sexes. The volunteers were subjected and approved during the first phase of the study, with a skill test specific for the modality (ITN). In the second phase, a test of simple reaction time was applied, stratifying the results by cognitive and motor time. It was used the ANCOVA test in order to identify differences for ITN, assuming the reaction time as an independent variable and the age as a covariate. Results show differences for ITN among the groups of cognitive reaction time adjusted for age (p=0,04) and there was no difference by observing the comparison among the results of motor reaction time (p=0,162). It is concluded that the cognitive reaction time is an important variable in the process for identifying talents in tennis.

Physical fitness of chinese and japanese junior track runners-can skeletal age and stature be useful for talent detection? / 体力科学

The present study was primarily designated as “Chino-Japanese cooperative study on physical fitness of junior track and field athletes” (1989) . The participants were male and female track runners of both countries ranging in age from 13 to 17 years.<BR>Skeletal age and stature for each sex and athletic event for the present series were compared between the two countries. The data of the present series were then compared with the earlier series, that is, the reference data derived from “Chino-Japanese cooperative study on physical fitness of children and youth” (1986) .<BR>Regarding the mean skeletal age of reference data (13 to 17 yrs.), the Japanese are more advanced (0.6 years in boys; 0.5 years in girls) than the Chinese, respectively. On the other hand, for the mean stature, the Chinese are taller (1.92cm in boys; 2.16cm in girls) .<BR>In the present series, the mean differences for skeletal age between the two countries show a tendency to be smaller than those in the reference data (0.38 years for boys and 0.39 years for girls in 100m runners; 0.15 years for boys in 1500m runners and girls in 800m runners), respectively.<BR>Although the mean differences of skeletal age between the two countries are becoming smaller, the stature of the Chinese boys and girls are getting taller than the Japanese (6.9cm in boys and 5.60cm in girls in 100m runners) . The mean differences are not so great as in 100m runners, however, it is 2.50cm in boys of 1500m runners and 4.05cm in girls of 800m runners.<BR>Comparison of the athletic records between the two countries was made and in general little difference was found. The Chinese records are more complete than the Japanese and show statistically significant difference particularly in 17 years old.<BR>In conclusion, the Chinese junior track runners seem to mature later skeletally or biologically than the Japanese, even though they are already taller than the Japanese. As a natural result, more gain in stature and more improvement in the athletic records will be expected for them. Otherwise some differences between the two countries in the process of sampling of the present study could be questioned.