RESUMO

Vertical jump is an important skill that influences volleyball performance. In this study, we analyzed the relationship between vertical jump performance and birth quartile of Brazilian male youth volleyball players. We calculated chi-square goodness-of-fit tests to compare the athletes' birthdate distributions in quarters of their birth years (Q1, Q2, Q3, and Q4) according to player age categories (U17, U18, U19, and U21). We calculated one-way ANOVAs to compare spike jump and block jump heights of players born in different quarters of the same year. Overall, we found a relative age effect (i.e., more players with birth dates early in the birth year) in U17 (p < .001), U18 (p < .001), U19 (p < .001), and U21 (p = .04). Regarding vertical jump performance, U18 athletes born in Q2 reached higher spike jump heights (p = .006) and block jump heights (p = .002) than athletes born in Q4, and U19 athletes born in Q1 reached higher block jump heights than athletes born in Q3 (p = .049). There were no significant differences in vertical jump performance across birth quartiles among U17 and U21 athletes. Thus, a relative age effect was present in all age categories but not always reflected in vertical jump performance. Volleyball coaches and policymakers are still advised to employ strategies to ensure fairer opportunities for players born later in the year of their eligibility dates, as we found RAE to be sometimes, but not always, related to higher spike or block jump heights even among these older adolescents and young adult athletes.

Assuntos

RESUMO

Purpose: Our purpose was to verify the existence of birthplace and relative age effect (RAE), as well as the association between birthplace effect and RAE among Brazilian athletes competing in the Olympic Games. Methods: Data included information about Brazilian Summer Olympic athletes from 1920 to 2021. To investigate RAE, athletes' birthdate was distributed into birth quartiles (Q1: Jan-Mar; Q2: Apr-Jun; Q3: Jul-Sep; Q4: Oct-Dec), while birthplace effect was assessed considering the state and the region (Southeast; Northeast; South; North; and Midwest) of birth. The Chi-square test (χ2) was used to verify differences between the birthplace effect and RAE. Results: The sample consisted of 388 Brazilian athletes of both sexes, distributed in 38 sports modalities from 23 Brazilian states (Southeast = 66.5%; South = 14.4%; Northeast = 12.1%; North = 1.5%; Midwest = 5.4%). For both sexes, most of the athletes were from the São Paulo state (37.4%), followed by Rio de Janeiro (18.3%), both from the Southeast region. For birthdate distribution according to birthplace, it was observed that the North region presented the highest frequency of athletes born in Q1 (50%), followed by the Northeast and Southeast regions. No significant differences were found for the birthplace effect (χ2 = 5.69, value of p = 0.128) and RAE between sexes (χ2 = 0.530, value of p = 0.912), nor was shown an association between the birthplace effect and RAE. Conclusion: Most Brazilian Olympic athletes are from the Southeast region, but no RAE was established regarding their birthplace. Results from the present study can guide sports public policies in Brazilian regions, especially in the Midwest, North, and Northeast regions, which are underrepresented in Brazilian high-performance sports.

RESUMO

O objetivo deste estudo foi analisar a existência e a influência do Efeito da Idade Relativa (EIR) em estudantes-atletas de futsal masculino de Mato Grosso de acordo com a categoria etária. A amostra foi composta por 486 estudantes-atletas masculinos de futsal de Mato Grosso das categorias A (15 a 17 anos) e B (12 a 14 anos) que disputaram os Jogos Escolares Mato-grossenses e os Jogos Estudantis de Seleções Mato-Grossenses de 2021. Para análise, foram realizados testes qui-quadrado (χ2) de aderência. Os resultados mostraram a presença do EIR na análise geral e nas categorias A e B, com maior representação de atletas nascidos no primeiro trimestre do ano. Conclui-se que o EIR é um fenômeno presente em estudantes-atletas de futsal masculino do estado de Mato Grosso.

The objective of this study was to analyze the existence and influence of the Relative Age Effect (RAE) in male Mato Grosso's futsal student-athletes according to age category. The sample consisted of 486 male futsal student-athletes from Mato Grosso, in categories A (15 to 17 years old) and B (12 to 14 years old) who competed in the 2021 Mato Grosso School Games and the Mato Grosso Student Selections Games. For analysis, chi-square (χ2) goodness of fit tests were performed. Results showed the presence of RAE in the overall analysis and in categories A and B, with a greater representation of athletes born in the first quarter of the year. It is concluded that RAE is a phenomenon present in male futsal student-athletes in the state of Mato Grosso.

El objetivo de este estudio fue analizar la existencia e influencia del Efecto de la Edad Relativa (EER) en estudiantes-atletas de fútbol sala masculino de Mato Grosso de acuerdo con la categoría de edad. La muestra estuvo compuesta por 486 estudiantes-atletas masculinos de fútbol sala de Mato Grosso de las categorías A (15 a 17 años) y B (12 a 14 años) que compitieron en los Juegos Escolares de Mato Grosso y los Juegos Estudiantiles de Selecciones de Mato-Grosso (Brasil) de 2021. Para el análisis, se realizaron pruebas estadísticas de ajuste chi-cuadrado (χ2). Los resultados mostraron la presencia del EER en el análisis general y en las categorías A y B, con una mayor representación de atletas nacidos en el primer trimestre del año. Se concluye que el EER es un fenómeno presente en estudiantes-atletas de fútbol sala masculino del estado de Mato Grosso.

RESUMO

Background: The relative age effect (RAE) suggests that, due to maturity, young athletes born in the first quartiles of the year may have advantages over those born in the last quartiles of the year. Thus, it is important to evaluate the RAE in different sports and to consider the particularities of the subdivisions of the sports categories. Objective: To analyze the RAE in the top 20 of the Brazilian rankings in different combat sports. Methods: Observational study that analyzed the national databases for the year 2019 (from categories U-11 to U-18) made publicly available by the Brazilian confederations of karate, taekwondo and fencing. We obtained data on date of birth, age category and body weight of all modalities, type of fencing competition weapon (Epee, Foie and Saber) and type of karate modality (kumite and kata) from the top 20 places in each ranking. The final sample consisted of 1,486 athletes (Age: 14.2 ± 2.3. Male-53.2%. Female-46.8%). To identify the RAE, we performed a contingency analysis and compared the results between the sexes within the same sport. Results: There was RAE in the U-11, U-12, U-15 and U-17 fencing categories (p < 0.05), being higher in the female categories (p < 0.05). The RAE was higher for males in the Epee test, and similar between the sexes for the Saber and Foie tests. In karate, RAE occurred in categories U-14 and U-16 (p < 0.05), being higher in males (p < 0.05). The RAE was similar between the sexes in the kumite modality (p < 0.05). There was no RAE for the kata modality in karate (p > 0.05) and for the Taekwondo categories (p > 0.05). Conclusion: The results showed the existence of a relative age effect in elite athletes ranked (top 20 places in each ranking) only for the sport of fencing and karate kumite.

RESUMO

This study examined the influence of birth date, salivary testosterone [sT] concentration, sexual maturity status, and general strength on the selection process of an elite Brazilian soccer club during a 12-month period, which was a 2nd phase of a 24-month selection process. The stature, body mass, sT, sexual maturity status [Tanner scale], and hand grip strength were assessed for 143 players during 2 weeks. From these 143 players, 100 players were dismissed [DIS] and 43 players were selected to integrate the club's under-14 squad. Following 1-year training period, the under-14 team was assembled with 9 players designated as starters [STA], and then, comparisons were conducted taking into account a group of non-starters (selected; SEL = 34 players) and STA (n = 09). The DIS, SEL, STA players, and reference population, were compared for birth distribution. A greater proportion of players was born in the first trimester in the STA [75.0%], SEL [57.1%] and DIS [50.0%] groups compared to the reference population [25.8%]. One-way ANOVA showed a higher sT for STA group [516.0 ± 129.9 pmol·L-1], compared to SEL [415.5 ± 117.9 pmol·L-1] and DIS groups [390.9 ± 84.9 pmol·L-1; p = 0.003), and Kruskall-Wallis test showed a higher gonadal development for STA compared to DIS [p = 0.001]. The current findings suggest a strong influence of birth date and biological maturation on young soccer players selection process. Soccer coaches should consider these influences when making decisions about player selection of elite youth players.

RESUMO

Abstract Aim: The present study aimed to investigate the prevalence of RAE in soccer players from different positions in Series A and B in 2020 Brazilian soccer, as well as the impact of RAE on the estimated market value of these players. Methods: Data from 1080 male elite soccer athletes were analyzed. Athletes were grouped according to birth quarters: Q1 (January-March), Q2 (April-June), Q3 (July-September), and Q4 (October-December) and the competitive level (Series A or B). Chi-square tests (χ2) were performed to compare the birthdates' distribution of athletes according to a competitive level and playing positions. Kruskal-Wallis test was used to compare the market values of players born in each of the quarters of the year across competitive levels and playing positions. The significance level was set at 5%. Results: The overall analyses showed the prevalence of RAE in Series A and B, with an overrepresentation of athletes born in the first two quarters of the year. The RAE analysis based on playing positions showed different from expected distributions for forwards, midfielders, and defenders in Series A. In Series B, only midfielders showed a difference from the expected distribution. As for the market values analyses, no differences were found based on the athletes' birth quarters, regardless of competitive level or playing position. Conclusion: Our results indicate that, although RAE is prevalent in Series A and B of elite Brazilian soccer, it does not seem to influence players' estimated market values.

Assuntos

RESUMO

The relative age effect (RAE) has been studied and demonstrated in the literature. Our study evaluated the influence of birth tertile on anthropometric variables, anaerobic parameters, and quantitative muscle ultrasound in school children. A transversal, comparative, non-randomized study was conducted with 159 participants (9.36 ± 0.84 years) recruited by purposive sampling, of whom 70 were girls (9.50 ± 0.77 years) and 89 were boys (9.25 ± 0.88 years). The sample was divided into groups based on the year of birth, and each group was divided into tertiles. The anthropometric parameters of body weight, height, and fat percentage were measured, and then a right quadriceps ultrasound was performed, followed by the evaluation of CMJ and continuous jumps. Comparison of tertile subgroups showed significant differences in the vertical jump, in girls (CMJ, PCMJ, PCMJR, PCMJDE, PCMJDER, and PP15) and in boys (PCMJ, PCMJR, PCMJDE, and PP15). The results indicate that being born in the first months of the year may have a positive influence on performance in anaerobic tests, such as vertical jump, and on the quantitative ultrasound results of the quadriceps.

Assuntos

RESUMO

This study examined individual, task, and environmental constraints that influence the career progression of youth Brazilian elite basketball players and the probability of reaching Novo Basquete Brasil (NBB) and to determine if the association of the relative age effect (RAE) is a key factor in the career progression. The sample consisted of 4,692 male players who were registered to participate in at least one U15, U17, or U22 youth Brazilian basketball championship between 2004 and 2018. Athletes who reached a high-performance level were coded like NBB players (9.6%). The birthdates, height, body mass, playing position, geographic region, club, competition category, and team performance were retrieved from the official data archive of the Brazilian Basketball Confederation and the National Basketball League. The maturity status was estimated using the predicted age at peak height velocity. A binary logistic regression examined the influence of each characteristic on the probability of a youth Brazilian basketball player to reach the NBB. The receiver operating characteristic (ROC) curves and the associated area under the curve (AUC) were used to assess the discriminant ability of the model. The taller and younger players not selected early into national teams, without specialization by playing position, who participated in U22 national championship, migrated to the southeast region, and remained in the formation process over time have a greater chance to reach the NBB. The ROC curve demonstrated an AUC of 93%. A combination of individual, task, and environmental characteristics influences the sport career of a young Brazilian basketball player in reaching the NBB. Further, early-maturing athletes have a greater chance to reach higher performances. RAE influences lower-level categories, but not a "NBB player's" career progression. The coaches, stakeholders, and practitioners should perform a holistic evaluation of sport talent in terms of a constraint-based theoretical model with the aim of avoiding bias produced by the maturational status and RAE in the youth Brazilian elite basketball.

RESUMO

Aim:The aim of this paper is to verify how cities' demographic rates and Human Development Index (HDI), as well as the birthdate of Brazilian elite soccer players influenced their identification and development.Methods:The sample was comprised of 5,359 players from the Brazilian Serie A Soccer Championship between 2003 and 2019. Players' birthdate and birthplace data were collected, as well as the HDI from their hometowns. Descriptive statistics, chi-square, Pearson correlation and linear regression tests were performed.Results:Results indicated that players born in the first semester of the year, in cities with a demographic rate of up to 100,000 inhabitants and HDI above 0.501, are more likely to play at the highest level (Serie A) of Brazilian soccer. Correlations were observed between birth quartile and HDI (r = -.059; se = 0.04; p < 0.001), birth quartile and demographic rates (r = -063, se = 0.03; p < 0.001), and between HDI and demographic rates (r = 0.458; se = 0.02; p < 0.001). The linear regression method yielded a valid model that included all three variables in this study (F(2) = 9.512; p < 0.001).Conclusion:Based on these findings, it is possible to conclude that birthdate, demographic rate and HDI are important factors in the identification and development of soccer players in Brazil.

Assuntos