Abstract Introduction: The relative age effect is prevalent in different elite team sports. However, little is known about this phenomenon in high-level adult male futsal players. Aim: The present study aimed to investigate the prevalence of relative age effect in Brazilian male elite futsal players, and its relationship with playing position and goals scored on Brazil National Futsal Leagues (BNFL) from 2016 to 2020. Methods: The distribution of birth dates, playing positions, and goals scored by male participants of the Brazil National Futsal Leagues were analyzed. Chi-squared tests were used to analyze the birth dates distribution based on quarters and semesters of the year, according to playing position (defender, winger, pivot, and goalkeeper) and scoring performance (high and low). Results: The overall analysis indicated that the relative age effect is prevalent on the pool of athletes analyzed. However, this effect was position-dependent, since relatively older athletes were overrepresented only in wingers and defenders playing positions. On the other hand, scoring performance was not associated with the relative age effect, since this effect was found in both performance levels. Conclusion: Relative age effects are prevalent in Brazilian male elite futsal athletes, especially for defenders and wingers. Considering the high level of competitiveness for spots in elite futsal teams, coaches and sports administrators must be educated about the prevalence of the relative age effect in this sporting context. This is necessary in order to reduce the inequalities generated by age categories based on arbitrary cut-off dates, which may reduce potential talent loss.

RESUMO O presente estudo teve como objetivo analisar como diferentes esquemas combinando estimativa de erro e frequência relativa de feedback extrínseco afetam a aprendizagem motora. Cinquenta e dois estudantes de graduação (30 homens, 22 mulheres) com idades entre 18 e 35 anos (M = 21,15, DP = 2,97), todos novatos na tarefa, praticaram uma habilidade de produção de força com diferentes combinações entre estimativa de erro e frequência relativa de conhecimento dos resultados. Quatro condições experimentais foram comparadas: 1) nenhuma estimativa de erro com feedback após cada tentativa; 2) nenhuma estimativa de erro com feedback a cada duas tentativas; 3) estimativa de erro seguida de feedback após cada tentativa e 4) estimativa de tentativa após feedback a cada duas tentativas. A análise do erro absoluto da força revelou efeito significante para a frequência de feedback [F(1, 76) = 4.209, p = 0.044, ηp 2 = 0.52] e estimativa de erro [F(1, 76) = 7.483, p = 0.008, ηp 2 = 0.77]. A análise do erro constante da força não revelou diferenças significantes para estimativa de erro [F(1, 76) = 2.323, p = 0.132, ηp 2 = 0.37], mas para a frequência de feedback [F(1, 76) = 8.481, p = 0.005, ηp 2 = 0.83]. Os resultados mostraram aprendizagem superior dos grupos que combinaram estimativa de erro após receber feedback, independentemente da frequência relativa apresentada. A associação entre estimativa de erro e frequência relativa de feedback extrínseco (alto ou moderado) parece favorecer o desenvolvimento de mecanismos de detecção de erros, evitando os efeitos da dependência de feedback extrínseco e, consequentemente, potencializando o aprendizado.

ABSTRACT The present study aimed to analyze how different schedules combining error estimation and relative frequency of extrinsic feedback affects motor learning. Fifty-two undergraduate students (30 males, 22 females) aged 18 to 35 years old (M = 21.15, SD = 2.97), all novices in the task, practiced a force-production task with different combinations between error estimation and relative frequency of knowledge of results. Four experimental conditions were compared: no error estimation with feedback after every trial; no error estimation with feedback every two trials; error estimation following by feedback after every trial-and-error estimation following feedback every two trials. The absolute force error analysis revealed a significant main effect for both feedback frequency [F(1, 76) = 4.209, p = 0.044, ηp 2 = 0.52] and error estimation [F(1, 76) = 7.483, p = 0.008, ηp 2 = 0.77]. The constant force error analysis did not reveal a significant main effect for Error Estimation [F(1, 76) = 2.323, p = 0.132, ηp 2 = 0.37], but did for Feedback Frequency [F(1, 76) = 8.481, p = 0.005, ηp 2 = 0.83]. Results showed superior learning of groups that combined error estimation following receiving feedback, regardless of feedback frequency. The association between error estimation and relative frequency of extrinsic feedback (high or moderate) seems to favor the development of error-detection mechanism, thus avoiding the effects of extrinsic feedback dependence, and consequently enhancing learning

Abstract Aim: To investigate the existence of relative age effect (RAE) in Brazilian water polo athletes according to sex and age category. Methods: The birthdate of 574 Brazilian water polo athletes were organized according to the athletes’ birthdates into quarters of the year (Q1, Q2, Q3, and Q4), and classified according to sex (male and female) and age category (U16, U18, U20, and senior). To verify the existence of RAE, the Chi-Square tests (χ2) were performed, and the effect sizes (ω) were calculated for each of the tests. We also calculated odds ratio (ORs) and 95% confidence intervals, setting the level of significance to 0.05. As post hoc analysis, multiple comparisons between quarters were performed, with Bonferroni's correction (significance level set to 0.0083 in these cases). Results: The results indicated an uneven distribution of birthdates for male water polo athletes (χ2 = 12.257; p = 0.007; ω = 0.173), with an overrepresentation of athletes born in the first (p < 0.006) and second (p < 0.002) quarters. When sex and age category were considered, male athletes presented uneven distributions in U20 (χ2 = 10.747; p = 0.013; ω = 0.345) and senior (χ2= 12.614; p = 0.006; ω = 0.383) categories. In females, no differences were found. Conclusion: We conclude that there is an uneven distribution of birthdates in male Brazilian water polo athletes, indicating the presence of RAE in this group.

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.

Abstract Aim: This study investigated the Relative Age Effect (RAE) in Brazilian track and field athletes based on sex, age category (U-16, U-18, U-20, U-23 and senior), and event type (sprints/hurdles, middle distance, long-distance, jumps, throws). Methods: Data from 2.259 male and 1.776 female elite track and field athletes, ranked top-50 in events held by the Brazilian Track and Field Confederation in 2019 were analyzed. To determine RAE athletes were divided into four quarters based on their months of birth, considering January 1st the cut-off date. The influence of sex, age category, and event types in the pervasion of RAE in Brazilian track and field athletes was assessed through Chi-squared tests. Results: Athletes born closer to the cut-off date were more frequent than athletes born further from this date were in male youth categories. This effect reduced as categories increased, even reversing in the senior category. Finally, RAE was more frequent in events in which athletic performance relies more on strength, speed, and power, which is the case of sprints/hurdles, jumps, and throws. Conclusion: RAE is particularly prevalent in young male Brazilian track and field athletes, which indicates that many potentially talented athletes are overlooked in youth tryouts because they were born months away from the cut-off date. Policies that reduce the disadvantages faced by relatively younger athletes are warranted in order to avoid the loss of potential sports talents.

Abstract Aims: This study investigated the existence of Relative Age Effect (RAE) in the selection process of male and female athletes in the Brazilian national handball teams according to age categories (U-18, U-21, and senior) and playing position (wings, backs, pivots, and goalkeepers). Methods: In order to determine RAE, athletes were divided based on their months of birth; quarters Q1 (January-March), Q2 (April-June), Q3 (July-September), and Q4 (October-December). Data were collected from the official Brazilian Handball Confederation (CBHb) website and included the athletes that participated in training and/or competitions composing the Brazilian national teams from 2014 to 2018. To determine the RAE on playing positions, age categories of male and female groups were pooled. Chi-squared tests were performed to investigate the RAE. Results: An over-representation of players born in Q1 and Q2 in the U-18, U-20, and senior categories of male teams and the U-20, and senior female teams were found. In the male teams, as the age category increased, RAE decreased, but still existed. Such distribution was reversed in the female athletes, with a higher RAE magnitude in the senior category as compared to U-18 and U-21. Additionally, it seems that RAE is dependent on the playing position only for male athletes (wings and backs) whereas RAE was found for all playing positions in female athletes. Conclusion: Overall, RAE was found in Brazilian national handball teams, but its magnitude and form of manifestation seem to be influenced by sex, category, and playing position.

Resumo O objetivo do presente estudo foi avaliar as diferenças no desempenho entre as condições de foco de atenção externo e interno e uma condição de demonstração online. Adicionalmente, se essas diferenças seriam observadas em um nível neuromuscular por meio da análise EMG, além das medidas de resultados tradicionais. Foi levantada a hipótese que sob a condição de demonstração os participantes teriam um desempenho melhor do que sob as condições de foco externo e interno. Também foi levantado a hipótese que a condição de demonstração apresentaria menor atividade EMG do que as condições de foco externo e interno. Além disso, esperava-se corrobora os benefícios do foco externo em relação ao foco interno, tanto nas medidas de resultado quanto de produto. Seis participantes do sexo masculino realizaram uma extensão de perna bilateral nas condições: foco de atenção interno, foco de atenção externo e condições de demonstração online. Os tempos de meta de contrações musculares foram definidos para ação muscular concêntrica (4 segundos) e ação muscular excêntrica (2 segundos). Um eletrogoniômetro foi usado para registrar a ativação muscular (medidas de produção) e o erro temporal foi usado para observar o desempenho (medidas de resultado). Os resultados mostraram que a condição de demonstração online obteve melhor desempenho do que a condição de foco externo e uma ativação muscular reduzida. No entanto, não foram encontradas diferenças entre o foco interno e as outras condições experimentais. Esses achados avançam no entendimento dos mecanismos que sustentam o foco de atenção, como o proposto pela Constrained Action Hypothesis.

Abstract The purpose of the present study was to examine whether there would be performance differences between external and internal focus of attention conditions and an online demonstration condition, and if these differences would be observed at a neuromuscular level through EMG analysis, in addition to traditional outcome measures. We hypothesized that under the demonstration condition participants would perform better than under external and internal focus conditions. We also hypothesized that demonstration condition would show smaller EMG activity than external and internal focus conditions. Furthermore, we hope to replicate the benefits of external focus in relation to internal focus, both in outcome and product measures. Six male participants performed a bilateral leg extension under internal focus of attention, external focus of attention and online demonstration conditions. Muscular contractions goal times were set for concentric muscle action (4 seconds) and eccentric muscle action (2 seconds). An electrogoniometer was used to record muscular activation (production measures), and temporal error was used to observe performance (outcome measures). Results showed that online demonstration condition obtained better performance than external focus condition and a reduced muscular activation. However, differences between internal focus and the other experimental conditions were not found. These findings advance in the understanding mechanisms underpining the focus of attention, such as proposed by Constrained Action Hypothesis.

Resumo O objetivo do presente estudo foi investigar a confiabilidade das demandas física, fisiológica (FC) e tática em configurações de pequenos jogos (PJ) em igualdade (3x3) e superioridade numérica (4x3) no futebol. Dezoito jogadores do sexo masculino de uma equipe de futebol jogaram entre si os dois tipos de PJ, com duas séries de 4 minutos e 4 minutos de pausa entre elas. Durante os jogos, as variáveis relacionadas à demanda física (distâncias, velocidades, acelerações) e fisiológica foram registradas utilizando-se um equipamento de GPS (15hz) e um cardiofrequencímetro. Os comportamentos táticos individuais propostos pelo Sistema de Avaliação Tática no Futebol foram registrados por um avaliador partir da análise da filmagem dos jogos. A confiabilidade das medidas foi verificada considerando os valores individuais de cada atleta em cada série de PJ, por meio do coeficiente de correlação intraclasse (CCI) e do erro padrão de medida absoluto e percentual (EPM e EPM%, respectivamente). Como resultado, um maior número de variáveis relacionadas às demandas física e fisiológica apresentaram valores de CCI significativos com classificação moderada a excelente em relação às variáveis relacionadas à demanda tática. Considerando as variáveis com valores de CCI significativos em ambas as configurações de jogo, o EPM% variou entre 3,0 e 42,0% para as variáveis físicas e para a FC, e de 31,6 a 75,0% para as variáveis relativas à demanda tática. Conclui-se que diversas variáveis relacionadas às demandas física e fisiológica apresentaram confiabilidade moderada à excelente. Diferentemente, a maioria das medidas relacionadas à demanda tática não foi confiável em ambos PJ.

Abstract The aim of this study was to investigate the physical, physiological (HR) and tactical demands of small-sided soccer games (SSG) with numerical equality (3x3) and numerical superiority (4x3). Eighteen male players of a soccer team played against each other both types of SSG, both played as two 4-minute bouts interspersed with 4-minute rest. Physical (distances, velocities and accelerations) and HR demands were recorded by a GPS system (15hz) and a heart rate monitor during SSG. The individual tactical behaviors proposed by the System of Tactical Assessment in Soccer were registered by an observer who analyzed the SSG videos. Reliability was verified calculating the intraclass correlation coefficient (ICC) and the absolute and percentage standard error of measurement (SEM and %SEM, respectively), both considering athletes’ individual scores in each SSG bout. As a result, higher number of variables related to physical and physiological demands presented significant ICC values, being classified as moderate to excellent in relation to variables related to tactical demands. Considering these variables that presented significant ICC values in both SSG, the SEM% values found for physical and physiological variables ranged from 3.0 to 42.0%, while those found for the tactical variables ranged from 31.6 to 75.0%. It could be concluded that several variables related to physical and physiological demands present moderate to excellent reliability. Differently, the majority of variables related to tactical demands were not reliable in both types of SSG.