The association between physical fitness and cognitive performance has been widely investigated in the literature. However, the neurophysiological mechanisms underlying this relationship are not yet clear. Here, we aim to evaluate the interactions between executive function measures, heart rate variability (HRV), and physical fitness in the context of the neurovisceral integration (NVI) theory. Twenty-eight healthy elderly subjects (>60 years) were submitted to evaluation of executive performance with three computerized tests: the N-back test measured working memory capacity, the Stroop Color test evaluated inhibitory control and selective attention, and the Wisconsin Card Sorting Test (WCST) evaluated abstract reasoning and cognitive flexibility. We also used the Physical Testing Battery for the Elderly to measure aerobic capacity, dynamic balance, upper body flexibility, and handgrip strength. Our results confirm the relationship between executive function and physical fitness, particularly between working memory, cardiorespiratory fitness, and dynamic balance. We also demonstrate an association between executive performance and HRV in older people, corroborating previous results from other groups obtained in young adults. However, our regression models did not indicate that HRV mediates the relationship between cognition and physical fitness in the elderly, suggesting that age-related degeneration of autonomic control can affect aspects of NVI in this population.

The aim of the present study was to investigate the effect of a short period of supplementation with glutamine dipeptide (GDP) on the acute responses to resistance training on the executive functions of people with HIV/AIDS. The sample consisted of 10 HIV+ women (45.00 ± 12.77 years old; 65.71 ± 12.04 kg; 1.54 ± 0.05 m) who were submitted to a randomized double-blind crossover procedure according to two experimental conditions: orally supplemented with 20 g/day of GDP or with maltodextrin for seven days. On the seventh day of supplementation all participants did cognitive function tests before and immediately after a resistance training session. Seven days of washout were adopted between conditions. Stroop and N-back tests were used to evaluate the executive functions. The training reduced the response time of each card in isolation and the latency time among them. GDP supplementation increased the magnitude of this effect, thus, reducing the latency time from the first to the last card in the Stroop test by almost 50% (P < 0.01). Considering the N-back test, there were no significant differences. It is suggested that GDP supplementation may increase the magnitude of the effect of an acute resistance training session in cognitive functions, particularly in the inhibitory control of people with HIV/AIDS. This trial is registered with NCT03236532.

RESUMOIntrodução: No esporte de rendimento, altas cargas de treinamento são necessárias para que ocorram adaptações biológicas que levem ao aprimoramento da forma física e do desempenho esportivo. Objetivo: Investigar o comportamento de variáveis psicológicas e fisiológicas, possíveis indicadores dos estados de estresse e recuperação, em jogadores de futebol ao longo da temporada esportiva, e a possibilidade da utilização desses como marcadores dos estados de treinabilidade dos atletas para prevenir quedas do desempenho e o overtraining. Métodos: Participaram deste estudo 14 jogadores de futebol (18,4 ± 0,6 anos, 9,64 ± 1,61 % com gordura e VO 2máx 49,46 ± 2,88 ml/kg/min) da categoria júnior de uma equipe de primeira divisão do Brasil. Foram monitorados a percepção de estresse e a recuperação por meio do questionário RESTQ-Sport, a variabilidade de frequência cardíaca (VFC) de repouso, analisada no domínio do tempo e da frequência, e o tempo de reação simples. Efetuaram-se três coletas de dados, um controle (C), outra após quatro semanas de treinamentos intensos (T1), e finalmente depois de quatro semanas de treinamentos leves (T2) realizados após T1. Resultados: Não foi encontrada diferença significativa em nenhuma das escalas do RESTQ--Sport e na VFC nos três momentos de coletas. O tempo de reação simples apresentou um aumento significativo (p = 0,047) em T1 em relação a C. Conclusão: Os resultados indicam que o tempo de reação foi a única variável sensível às alterações do treinamento estudado, podendo ser considerado um bom indicador da treinabilidade dos atletas.Palavras-chave: estresse fisiológico, frequência cardíaca, recuperação de função fisiológica, tempo de reação. ABSTRACT Introduction: In the performance sports, high training loads are necessary for biological adaptations to occur leading to the improvement of fitness and sports performance. Objective: To investigate the behavior of the psychological and physiological variables, indicators of possible states of stress and recovery in soccer players throughout the sports season, and the possibility of using these as markers of the conditions of athletes trainability to

We read with great interest the article by El Agaty, Kirmani, and Labban (2016) which evaluated the heart rate variability (HRV) during recovery from exercise in overweight healthy female young adults.According to the authors, the results provided evidence that overweight is associated with delayed vagal reactivation after exercise.We would like to add some comments and contributions to this article.Although many studies have shown an autonomic dysfunction at rest in obese subjects, little is known about the impact of obesity on postexercise cardiac autonomic recovery (Eyre, Duncan, Birch, & Fisher, 2014). The autonomic stress imposed by exercise continues during the postexercise period, with parasympathetic reactivation and sympathetic withdrawal (Peçanha et al., 2017). For this reason, HRV analysis during the postexercise period has been proposed to be a surrogate marker of the cardiac autonomic recovery (Peçanha et al., 2017).Heart rate variability is usually measured during 5-min rest periods or other stationary condition to guarantee the minimum points to reliably assess of HRV (TaskForce, 1996). The stationary condition is needed in order to assume the "stationarity of the data," a mathematical concept that must be present in the heart rate time series for the spectral analysis of HRV (Peçanha et al., 2017). However, this is impossible for the analysis of HRV after exercise (Peçanha et al., 2017). Goldberger et al. (2006) proposed an alternative for the analyzing HRV during recovery phase from exercise, since the problem with postexercise HRV analysis could be minimized by dividing the entire recovery period into short segments and analyzing HRV in each of them. These authors suggest that the root-mean square differences of successive RR intervals calculated in 30s (RMSSD30s) segments seem to represent accurately the parasympathetic reactivation after the exercise.However, this alternative is problematic for the frequency domain HRV analysis, because there is variation of parasympathetic and sympathetic modulations (Peçanha et al., 2017). Therefore, using the conventional frequency domain approach to perform spectral analysis of the postexercise recovery curve will result in inconsistent values, since this is unable to catch the time-related variations in frequency and amplitude throughout the recovery period (Peçanha et al., 2017).Consequently, the spectral analysis of the whole recovery time in the postexercise period has been discouraged (Peçanha et al., 2017). Although this study presents an important research question,their results should be viewed with caution since the conclusions were based on the frequency domain data, which is not indicated to represent HRV postexercise recovery (Peçanha et al., 2017). Also, the RMSSD data, which has shown good reproducibility and represent the parasympathetic system (Peçanha et al., 2017), was not different between the recovery period and baseline in neither groups.Another important aspect that needs to be considered is the exercise intensity, which affects auton...

High-intensity physical exercise favors anaerobic glycolysis and increases lactatemia. Lactate is converted back to glucose in the liver, so that the lactate threshold, an indicator of physical performance, must be related to the gluconeogenic capacity of the liver. This research assessed the effect of a high-intensity interval resistance training (HIIRT) on liver gluconeogenesis from lactate. Swiss mice were trained (groups T) on vertical ladder with overload of 90% of their maximal load. Control animals remained untrained (groups C0 and C8). In situ liver perfusion with lactate and adrenaline was performed in rested mice after six hours of food deprivation. There were larger outputs of glucose (T6 71.90%, T8 54.53%) and pyruvate (T8 129.28%) (representative values for 4 mM lactate) in the groups trained for six or eight weeks (T6 and T8), and of glucose in the presence of adrenaline in group T8 (280%). The content of PEPCK, an important regulatory enzyme of the gluconeogenic pathway, was 69.13% higher in group T8 than in the age-matched untrained animals (C8). HIIRT augmented liver gluconeogenesis from lactate and this might improve the lactate threshold. Bullet points: The liver metabolizes lactate from muscle into glucose. Physical training may enhance the gluconeogenic capacity of the liver. As lactate clearance by the liver improves, lactate threshold is displaced to higher exercise intensities.

Para mim, startup é um negócio ou uma organização (não necessariamente precisa ser uma empresa com fins lucrativos) em estágio inicial, que está propondo uma solução inovadora, em busca de um modelo de negócio altamente escalável, geralmente baseado no uso de tecnologia que suporta e permite um alto ganho de escala. Se você já está lá na frente, muito maduro, você não é mais startup. Você pode até manter elementos da cultura, pode ter nascido como startup, mas você não é mais startup. KC: Como você vê o ecossistema atual de startups no Brasil? Está otimista com o cenário?

O estresse é um elemento potencializado e ressignificado em esportes de aventura conforme cada sujeito reage aos riscos, desafios e incertezas do ambiente. Considerando essa temática, acompanhamos os momentos mais estressantes no voo-livre, entremeando a reação fisiológica com a fala dos sujeitos pesquisados, no limite da possibilidade de diálogo/confronto sob uma perspectiva biopsicossocial. O recorte privilegiou o esporte de risco como opção de lazer, praticado por pessoas comuns, que obtém na aventura contraponto às tensões e estresse do cotidiano. Para tanto, realizamos observações diretas durante um ano e entrevistamos quatro pilotos. Em complemento, registramos a frequência cardíaca (FC) desses sujeitos durante as diferentes etapas do voo-livre. Conforme os resultados, a FC apresentou patamares agudos e residuais elevados, que são coerentes com a história narrada por cada sujeito. Os pilotos demostraram que a percepção de risco frente à prática esportiva provoca uma tensão necessária para a produção subsequente de sensações transcendentes e prazerosas. Nesse sentido, ponderamos sobre a equação entre a segurança física e emocional na atividade e a percepção subjetiva do risco, ambas vistas como indissociáveis à aventura experimentada.

Gender differences in spatial abilities favor males in both childhood and adulthood. During early development, this discrepancy can be attributed, among other things, to the influence of an early testosterone surge in boys, societal stereotypes, and expectations about gender. In the present work, we created a spatial task (including letter rotation and letter mirroring) which used letters as stimuli and evaluated the performance of school-aged children (6–10 years old). During this age period, children are being taught literacy skills which rely on the reorganization of cortical networks and the breakdown of mirror generalization. We divided our sample (N = 142, 73 females) into two age groups: 1st–2nd (literacy acquisition; N = 70, 33 females) and 3rd–5th (literacy consolidation; N = 72, 40 females) graders. While boys performed significantly better in letter rotation in the older group, girls’ performance remained substandard in both groups. This pattern is reversed for the mirror task, with older girls outperforming their younger counterparts and boys having similar performance in the two groups. Since the age period of our sample is not associated with large variations in the levels of reproductive steroids, we propose that the similarity of performance between younger and older girls in mental rotation of letters could be associated with society’s traditional attitudes and expectations on the relationship between visual–spatial skills and gender. As for the mirror task, while only girls had a significant difference between the two age groups, boys did show an improvement, as expected for the inhibition of mirror generalization for letters during reading acquisition.