The Use of a Just Noticeable Difference Approach to Improve Perceptual Acuity Ability in Male Runners.

We were interested in micro-variations in an athlete's psychophysical state that separate peak exertion from physiological collapse. Thus, we measured perceptual acuity in runners using a classic psychophysical approach, the just noticeable difference (JND) on two standard stimuli runs at treadmill speed corresponding to 70%VO2max and 80%VO2max. Thirty-four male runners (M age = 35.26, SD = 7.33 years) first performed a maximal treadmill test to determine the speed of a standard exercise bout for the JND trials. The JND trials consisted of four 5-minute running bouts on a treadmill with 5-minute rests between bouts. For bouts 1 and 3, participants ran at the standard stimuli pace, but for bouts 2 and 4, they adjusted their speeds to achieve a level of exertion at a JND above/below the SS. They achieved differences in the final 30 seconds of the VO2 between each JND bout and the previous standard stimuli at just above (JND-A) and just below (JND-B) the JND perceived exertions. We used a Generalized Linear Model analysis to compare the JND-A and JND-B within and between ventilatory threshold groups (lower/higher) in absolute and relative VO2 and in terms of the total JND magnitude. The magnitude of JND-A was greater than that of JND-B at 70%VO2max and 80%VO2max in absolute units (70%VO2 Δ = 2.62; SE = 0.37; p < .001; 80%VO2 Δ = 1.67; SE = 0.44; p = .002) and in relative units (70%VO2max Δ = 4.70; SE = 0.66; p < .001; 80%VO2max Δ = 2.96; SE = 0.80; p = .002). The total magnitude was greater in the 70%VO2max trial than 80%VO2max in absolute units (70%VO2 M = 3.78, SE = 0.31 mL·kg-1·min-1; 80%VO2 M = 2.62, SE = 0.37 mL·kg-1·min-1; p = .020) and in relative units (70%VO2max M = 6.57, SE = 0.53%VO2max; 80%VO2max M = 4.71, SE = 0.64%VO2max; p = .030). The JND range narrowed when physiologic demand increased, for both physical (speed) and psychological (RPE) variables.

O efeito da competição sobre o estado de humor de jovens atletas de jiu-jitsu / The effect of competition on the mood state of young jiu-jitsu athletes

O Jiu-Jitsu é considerado um excelente exercício físico que pode ser realizado em todas as faixas etárias, aperfeiçoando os componentes físicos do corpo, assim como os aspectos sociais e emocionais de seus praticantes. No intuito de entender como uma luta de Jiu-Jitsu influencia no estado de humor dos seus praticantes, surge o objetivo deste estudo, que foi verificar os efeitos de uma competição sobre o estado de humor de jovens atletas de jiu-jitsu. Após os critérios de inclusão, o grupo do estudo foi composto por 12 atletas com idade entre 15 e 17 anos, do sexo masculino, praticantes de jiu-jitsu. A coleta de dados foi realizada na semifinal de um campeonato na cidade de Chapecó - SC. Os estados de humor dos atletas foram avaliados por meio da Escala de Humor de Brunel (BRUMS), em três momentos distintos identificados em controle, pré-luta e pós-luta. Para análise dos dados, os valores foram avaliados de maneira descritiva e inferencial. Após a análise de normalidade com os testes de Shapiro-Wilk, optou-se pelos testes de Anova de medidas repetidas e de Friedman com o Post Hoc de Bonferroni. Observou-se que no grupo vencedor houve aumento na fadiga pós luta (p<0,001), enquanto no grupo perdedor ocorreu aumento nos valores de depressão (p<0,001), raiva (p<0,001), fadiga (p<0,001) e diminuição do vigor (p=0,013) pós competição em relação aos valores controle e pré. Portanto, no grupo estudado a vitória ou a derrota influenciou o estado de humor dos atletas participantes, sendo que a derrota exprimiu relação com o aumento de sentimentos negativos como a depressão, a raiva e a fadig

Jiu-Jitsu is considered an excellent physical exercise that can be performed in all age groups, acting and perfecting the physical components of the body, as well as the social and emotional aspects of its practitioners. In order to understand how a Jiu-Jitsu fight influences the mood of its practitioners, the objective of this study arises, which was to verify the effects of a competition on the mood of young jiu-jitsu athletes. After the inclusion criteria, the study group was composed of 12 male athletes aged between 15 and 17 years old, jiu-jitsu practitioners. Data collection was carried out in the semifinal of a championship in the city of Chapecó - SC. The athletes' mood states were assessed using the Brunel Mood Scale (BRUMS), in three distinct moments identified in control, pre-fight and post-fight. For data analysis, the values were assessed in a descriptive and inferential manner. After the analysis of normality with the Shapiro-Wilk tests, we opted for the Anova tests of repeated measures and the Friedman tests with the Bonferroni Post Hoc. It was observed that in the winning group there was an increase in post-fight fatigue (p <0.001). While in the losing group there was an increase in the values of depression (p <0.001), anger (p <0.001), fatigue (p <0.001) and a decrease in vigor (p = 0.013) after competition in relation to the control and pre values. Therefore, in the studied group, victory or defeat influenced the mood of the participating athletes, and the defeat expressed a relationship with the increase in negative feelings such as depression, anger and fatigue.