ABSTRACT
Introduction: The aim of the present study was to evaluate the influence of acute transcranial direct current stimulation (tDCS) on physical and subjective responses in professional rowing during the 2,000-m time trial test. Methods: Seven rowers (age 20.86 ± 4.49 years; weight 71.66 ± 7.97â kg) participated in this randomized triple-blind trial with a crossover experimental design. The protocol consists of 2 days with different conditions (anodal and sham). The tDCS anodic stimulation conducted was 2â mA for 20â min in the left temporal cortex (2.5â cm from the F7 zone and 2.5â cm from the T3 zone), targeting the left insular cortex. In the sham moment, the participants experienced 30â s of stimulation. Afterward, they performed a standardized progressive warm-up for 15â min, following the Brazilian Rowing Confederation's assessment protocols, and rested for 3â min before the test started. All procedures were made on an indoor rowing machine, which allowed the capture of performance variables such as time performed, power in watts (W), pace (m/min), and stroke rate (strokes/min). The ratings of perceived exertion [Borg scale (CR-20)] were recorded in each 2-min during the test. Results: The results presented differences in power [Z: -2.371; p = 0.018; effect size (ES) = -0.896 (large)] and pace [Z: -2.371; p = 0.018; ES = -0.896 (large)] and time performance [Z: -1.612; p = 0.107; ES = -0.609 (large)] throughout the protocol for the anodal moment. Discussion: However, no differences for the other variables were found. According to the results, the current tDCS with the present protocol improved the physical performance at the 2,000-m time trial Test providing ergogenic aid.
ABSTRACT
O estudo teve como objetivo analisar e comparar as frequências dos comportamentos táticos desempenhados por jogadores de futebol das categorias Sub-13 e Sub-15. Foram realizadas 1.145 e 1.304 ações pelos jogadores das categorias Sub-13 e Sub-15, respectivamente. Para avaliar as ações táticas foi utilizado o instrumento de avaliação FUT-SAT. Utilizou-se o software SPSS for Windows(r), versão 19.0, para as análises descritivas, comparativas de frequência e percentual das ações táticas. Para a categoria Sub-13 os resultados indicaram maior frequência das ações táticas para os princípios ofensivos "Mobilidade" e "Unidade Ofensiva" e defensivamente, "Unidade defensiva" e "Contenção". Na categoria Sub-15, ofensivamente foram preponderantes diferenças para os princípios táticos "Espaço" e "Cobertura ofensiva", e defensivos, "Unidade defensiva" e "Contenção". Constatou-se que em ambas categorias, as equipes realizam um jogo ofensivo mais estático balizado por trocas de passes, e defensivamente, apoiam-se num jogo mais individual, em bloco baixo e desorganizado.
The present study wishes to analyse and compare frequency of tactical behaviour by football players of U-13 and U-15 category. 1.145 and 1.304 actions were accomplished by, respectively, to the U-13 and U-15 players. The evaluation instrument used was FUT-SAT to analysed tactical actions. Was used SPSS software for Windows(r), 19.0 version, to the descriptive analysis, comparative frequency and perceptual of tactical actions. To U-13 level the results shows a bigger frequency to tactical actions by offensive principles "Mobilit" and "Offensive Unit" and defensively, "Defensive Unit" and "Contention". Offensively at U-15 category were preponderant the difference of tactical principles "Space" and "Offensive Coverage" and defensively "Defensive Unit" and "Contention". In both categories was seen that the teams practiced a more static offensive game guided by passes, and defensively, they hold more an individual game, in an unorganized and low block.
