The present study aimed to investigate whether the form and amount of declarative tactical knowledge (DTK) and procedural tactical knowledge (PTK) influence cognitive effort during soccer performance among young players. We assessed 36 male players from a Brazilian first-division soccer club; participants averaged 14.89 ( SD = 1.42) years of age. We evaluated DTK from video simulation tests and PTK through the System of Tactical Assessment in Soccer. We assessed cognitive effort by measures of pupil diameter using Mobile Eye Tracking-XG while players viewed soccer video scenes and made game-related play decisions. After the assessment of tactical knowledge, we categorized the sample according to players’ tactical knowledge into participants with higher and lower PTK and higher and lower DTK. Subsequently, we examined the both PTK and DTK groups on cognitive effort. Our results suggest that tactical knowledge influences cognitive effort in that players with higher PTK and DTK displayed less cognitive effort during soccer performance tasks. In conclusion, we observed that PTK and DTK influenced the cognitive effort younger soccer players expended while viewing soccer scenes and making soccer performance decisions.

Purpose. the aim of the study was to verify the effect of mental fatigue on tactical actions quality and the intensity of covered distance in soccer players. Methods. Six U-15 male soccer players participated in this study (14.7 ± 0.59 years of age). For data collection, the FUtSAt and GPSports® (SPI-HPU) systems were applied. to induce mental fatigue, the Stroop task was used for 20 minutes. the individuals were evaluated in 2 conditions: mental fatigue and control (with and without the Stroop task). Statistical analysis was performed with the Kolmogorov-Smirnov test, t-test, and Wilcoxon test. Results. the results displayed significant differences in actions related to principles of balance (p = 0.02), defensive unity (p < 0.01), and total defensive actions (p = 0.02), as well as in the covered distance in intensity related to zones 3 (p = 0.03) and 6 (p < 0.01). In mental fatigue, the players revealed a decrease in tactical action quality referring to movements that aimed at numerical stability in relations of opposition and at defending in unity and in block, and covered greater distances in zones 3 and 6. Conclusions. Mental fatigue modified the players' movement dynamics on the pitch with reference to the quality of tactical actions and covered distance intensity.

Could the Human Development Index and Birth-Date of the players influence the climbing up to higher performance in Soccer?Abstract: The present study verifies the possible influence of the human development index (HDI) and the birth-date (BD) on the climb up to higher performance in sports, considering Brazilian football context. The sample comprised all 643 players from 20 teams of the Premier Football League in Brazil. The data were collected from official website of Brazilian National Federation, United Nations Development Programme and Brazilian Institute of Geography and Statistics. Descriptive analysis, Kolmogorov-Smirnov test, chi-square test (²), Pearson correlation and Kruskall-Wallis H test were carried out. The level of significance was set at α=0.05. The results suggested that contextual factors associated with size and HDI of birth-place and birthdate contribute to the achievement of the Premier Football League. Thus, players were born in the first months of the year and in cities with medium or higher HDI had more conditions to climb up the elite level of Brazilian Football.

RESUMOO objetivo do estudo foi comparar a eficiência do comportamento tático entre os jogadores de futebol de diferentes categorias etárias. A amostra foi composta por 400 jogadores divididos em quatro categorias (sub-11, sub-13, sub-15 e sub-17), que realizaram no total 23.855 ações táticas. Para avaliação da eficiência do comportamento tático dos jogadores foi utilizado o FUT-SAT. Para o tratamento estatístico, foram realizadas análises descritivas, os testes Kolmogorov-Smirnov, Kruskal-Wallis, Mann-Whitney e foi considerado um nível de significância de p<0,05. Os resultados indicam que a eficiência do comportamento tático tende a aumentar ao longo do tempo, com exceção da categoria Sub-15 que apresenta uma queda acentuada em relação às demais. Assim é possível concluir que existem variações na eficiência do comportamento tático de jogadores de futebol de diferentes categorias etárias. Palavras-chave: Futebol. Comportamento tático. Categorias etárias. ABSTRACTThe aim of this study was to compare the tactical behavior efficiency between soccer players from different age levels. The sample comprised 400 players from four age groups , who performed 23,855 tactical actions. Players' tactical behavior efficiency was assessed through FUT-SAT. Statistical procedures included descriptive analysis and the tests Kolmogorov-Smirnov, Kruskal-Wallis and Mann-Whitney. The significance level adopted was p<0.05. Results indicated that the tactical behavior efficiency tends to increase over time, except for the U-15 age level, that displayed an accentuated drop in relation to the others. It is concluded that the efficiency of tactical behavior of the players in soccer displayed differences across different age levels.

This is an accepted manuscript (pre-print version) of an article that has been published in the Journal of Sports Sciences. You may download the published version directly from the journal (homepage: https://www.tandfonline.com/toc/rjsp20/current).