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This study aimed to analyze the validity and reliability of a smartphone app (i.e., Encephalapp Stroop) to measure cognitive performance. Ten physically active individuals (mean age: 25.2 ± 4.3 years) participated in three laboratory visits. In a randomized sequence, subjects completed cognitive assessments using the app and a computer separately. The response times from 100 measurements for congruent and incongruent stimuli were compared between the two devices (app and computer) using the intraclass correlation coefficient, Pearson product-moment correlation coefficient (r), Cronbach's alpha (α), and Bland-Altman plots. There was excellent agreement between the computerized Stroop and the app version for response times for congruent (ICC = 0.806, p < 0.001; Bland-Altman bias = 41.3 ± 56.4 ms, p < 0.001) and incongruent stimuli (ICC = 0.755, p < 0.001; Bland-Altman bias = 76.4 ± 75.1 ms, p < 0.001). In comparison to the computerized version, the app demonstrated a moderate correlation for response times of congruent (r = 0.678, p < 0.001) and incongruent (r = 0.623, p < 0.001) stimuli. The results of the present study indicate that the response times of congruent and incongruent stimuli can be easily, accurately, and reliably evaluated using a mobile app.

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In this study we aimed to analyze the repeated effect of stroboscopic vision training on perceptual-cognitive skills in soccer players. A total of 28 male soccer players participated in this experimental and randomized study with parallel groups. The soccer players were pair-matched according to perceptual-cognitive skills and randomized into two groups: Stroboscopic vision training and Control. Multiple object tracking, anticipation, and decision-making skills were measured before and after the 8-week intervention. An increase in multiple object tracking (p < 0.05) and decision-making skills (p < 0.05) from baseline to post-experiment was found in both groups without main group effect (p > 0.05). The findings showed an increase in anticipation skill from baseline to post-experiment in both groups (p < 0.05), with higher anticipation skill for the stroboscopic group than in the control group post-experiment (p < 0.05). Thus, we conclude that repeated stroboscopic vision training could improve anticipation skill in soccer athletes.

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Abstract Aim: Increasing age is associated with significant changes in athletes' performance; however, it is not yet known how increasing age could influence the performance of triathletes. In this sense, the present study aimed to investigate how the performance of two elite triathletes (HCK and AD), who participated and finished the Olympic Games in Sydney, Athens, Beijing, and London, could change over the years. Methods: This study reports two cases (male and female) with cross-sectional and retrospective characteristics that describe how the increasing age changes the performance of two elite triathletes who participated in four consecutive Olympics (2000, 2004, 2008, and 2012). Pearson correlation test was used to verify the correlation between the performance and age of the triathletes. A value of p < 0.05 was assumed to show statistical significance. Results: The results suggest that both triathletes showed impaired performance at the Summer Games in Athens in 2004. When the two athletes were analyzed together, positive correlations were observed between age and transition 1 (T1; swim-to-cycle) and transition 2 (T2; cycle-to-run). Also, a high correlation was found between T2 and age for HCK but not for AD. The results showed a significant correlation between increasing age and a reduction in running performance for HCK. Conclusion: Although the two triathletes improved overall time throughout the Olympic Games, this improvement did not correlate with age. Thus, the increasing age does not seem to impact these two athletes during the four Olympic events.

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Abstract Aim: This narrative review aimed to explore the effect of mental fatigue on physical, technical, and tactical performance in ball sports. Methods: Three Databases, PUBMED, SCOPUS, and SCIELO, were used to search for a scientific publication. The criterions adopted were: a) published in a peer-reviewed journal; b) adopted at least one manipulation check related to mental fatigue; c) mental fatigue induced by a cognitive task before the outcome task, and d) study participants were ball sports athletes. Result: The quality of this narrative review was rated at 11 (SANRA scale 0-12), and the papers analyzed were published between 2015 and 2022. Twenty-one experimental studies were included in this review. Most studies were in invasion sports (n = 13; 72%), and non-ecological tasks were used to induce mental fatigue (n = 15; 83%). Regarding performance in endurance tests, mentally fatigued athletes had performance impaired. However, when assessed during a small-sided or simulated game, data were inconclusive within the literature. Moreover, athletes presented attenuated perceptual skills (e.g., visual field). Consequently, this worsened motor skills, technical-tactical performances, and tactical behavior. Conclusions: Cognitively demanding tasks should be avoided before training and sports competitions because they can lead the athlete to mental fatigue and impair performance. This impairment is identified in physical performance (endurance tasks) and technical and tactical performance. Finally, it is recommended that athletes do not perform tasks that cause mental fatigue 2 h before the sports event.

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BACKGROUND: The effect of MF induced by exposure time to social media smartphone apps on inhibitory control, heart rate variability (HRV), and high-intensity physical effort following a resistance exercise session might indicate whether strength and conditioning professionals should suggest avoiding smartphone usage before a resistance exercise session. AIM: The objective of this study was to analyze the effect of mental fatigue on inhibitory control, HRV, and countermovement jump (CMJ) in trained adults after resistance exercise. METHODS: A total of 16 trained males (21.4 ± 3.3 years) volunteered in this study. The participants performed resistance exercises with and without mental fatigue. The Stroop Task, countermovement jump, and heart rate variability were evaluated before and after the resistance exercise. The participants used smartphones in the mental fatigue condition, whereas the participants watched TV in the control condition. RESULTS: No condition × time interaction was found for the Stroop accuracy (p = 0.87), CMJ (p = 0.68), SDNN (p = 0.15), or pNN50 (p = 0.15) in the heart rate variability. An interaction was found for Stroop response time (p = 0.01) with a higher response time for the mental fatigue condition (p = 0.01). CONCLUSIONS: Mental fatigue impaired the inhibitory control performance after a resistance exercise session in trained adults.

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We investigated the acute effects of mental fatigue induced by 30-minute use of smartphone social network apps on volume load in resistance training among recreationally trained adults. Sixteen (n = 16) adults of both sexes performed three sets of a half back-squat exercise to failure with 80% of 15RM, interspersed with 3-minutes of passive recovery between sets, before and after two different cognitive tasks: (a) use of smartphone social network apps; and (b) watching a documentary. We assessed mechanical variables and ratings of perceived exertion during the strength exercise. Relative to the documentary-viewing control condition, a 30-minute exposure to smartphone social network apps led participants toward increased perception of mental fatigue (p = 0.004) and lower volume-load during the strength exercise (p = 0.006). There were no significant differences in perceived exertion between conditions (p = 0.54), participants' motivation (p = 0.277), intra-set mechanical variables (p > 0.05), or blood lactate concentrations (p = 0.36). Our findings of an isolated possible higher-than normal RPE without changes in physiological variables, accompanying the lower volume-load in the mentally-fatigued participants support psychological, rather than physiological, bases for mental fatigue effects.

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The intensity employed in the agonist-antagonist paired-set (AAPS) system may influence neuromuscular performance due to increased fatigue and decreased antagonist coactivation. However, it is not yet known whether performing submaximal repetitions at different intensities (i.e., wit h out m uscle failure) negatively affects agonist muscle performance. The aim of this study was to verify the acute effect of the AAPSsystem performed at different intensities with submaximal repetitions. 20 trained m ales in resistance training (RT) (21.8 [3.1] years; 76.9 [9.7] kg; 1.7 [0.0] m; 24.3 [2.6] kg/m2 ) participated of this investigation. All the participants were allocated in a randomized order in one of the two AAPS configurations: high-load (HL) or low-load (LL). In the HL condition, the individuals were submit t ed to one set of eight repetitions at 75% of one-repetition maximum (1RM) in the knee flexion (i.e., antagonist), followed by 75% 1RM knee extension (i.e., agonist) exercise until momentary concentric failure. In t he LL condition, they performed one set of 12 repetitions at 50% 1RMin the knee flexion, followed by knee extension at 75%1RM also until momentary concentric failure. Both experimental conditions p resented similar values for the number of repetitions, without significant difference (p= 0.66, ES= 0.15). Thus, our data suggest that the adoption of AAPS system without an increase of the antagonist fatigue and consequently no reduction of coactivation, acutely, may not lead to increased p erfo rm an ce o f target musculature during a resistance exercise session...(AU)

A intensidade empregada no sistema agonista-antagonista pareado por série ( AAPS) pode influenciar o desempenho neuromuscular devido ao aumento da fadiga e diminuição da co ativação do antagonista. No entanto, ainda não se sabe se realizar repetições submáximas em diferentes intensidades (i.e., sem falha muscular) afeta negativamente o desempenho muscular. O objetivo deste estudo foi verificar o efeito agudo do sistema AAPS realizado em diferentes intensidades com repetições submáximas. 20 homens treinados em treinamento resistido (TR) (21.8 ± 3.1 anos; 76.9 ± 9.7 kg; 1.7 ± 0.0 m; 24.3 ± 2.6 kg/m2 ) participaram desta investigação. Todos os participantes foram alocados, de forma aleatória, em uma das duas configurações do sistema AAPS: alta-carga (AC) ou baixa- carga (BC). Na condição AC, os indivíduos foram submetidos a uma série de oito repetições a 75% 1RMno exercício de flexão do joelho (i.e., antagonista), seguido por uma série a 75% 1RM de extensão do joelho até a falha oncêntrica momentânea. Ambas as condições experimentais apresentaram v alores sim ilares para o número de repetições, sem diferença significante (p = 0.66, TE = 0.15). Assim, nossos dados sugerem que a adoção do sistema AAPSsem aumento da fadiga do antagonista e consequentemente sem redução da coativação, agudamente, pode não levar ao aumento do desempenho da musculatura alvo durante uma sessão de exercício resistido...(AU)

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The aim of this study was to analyse the effect of mental fatigue on passing decision-making in professional soccer athletes. A controlled and counterbalanced cross-over design was adopted consisting of three visits with a 1-week interval between sessions. Twenty professional soccer male athletes participated in three randomized conditions divided into three visits: control, 15-min Stroop task, and 30-min Stroop task. Inhibitory control was accessed by the Stroop task (accuracy and response time) before and after induced mental fatigue protocol. The athletes played a training match (90-min) following the experimental conditions. The Game Performance Assessment Instrument (GPAI) was used for the passing decision-making analysis. The GPAI analysis showed impaired passing decision-making performance following the 30-min Stroop task compared with the 15-min and control condition (F (2,17) = 6.99, p = .01). Moreover, an increase in response time during the Stroop task was found following 30-min Stroop task condition (F (2,17) = 6.57, p = .03) compared to 15-min of Stroop task and control conditions. Prolonged cognitive tasks may be considered a mediating factor in passing decision-making performance in male professional soccer athletes throughout a full-length training match. Thus, athletes should avoid highly demanding-cognitive tasks before a soccer match. Future studies are required to explore more ecological cognitive tasks to induce mental fatigue (i.e. smartphones and video-games) and their effects on other performance indicators (e.g. physical, technical, tactical) in a full-length training match setting.

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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.

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Background: Increased handgrip strength has been associated with lower cardiovascular and non-cardiovascular mortality in different populations. In patients with hypertension, arterial stiffness relates to cardiovascular mortality. However, whether muscle strength is associated with arterial stiffness in hypertensives is unknown. Thus, the objective of this study was to analyze the association between handgrip strength and arterial stiffness parameters in hypertensive patients. Methods: Seventy-two hypertensive patients completed all evaluations and were included in the analysis. The ambulatory arterial stiffness index (AASI) was obtained based on 24-h ambulatory blood pressure monitoring. Carotid-femoral pulse wave velocity (cfPWV), and reflected wave indicator (AIx and AIx@75) were estimated using applanation tonometry technique, whereas handgrip strength test was performed using a digital dynamometer. Crude and adjusted linear regression models were performed. Results: The crude analysis revealed a negative association between handgrip strength and AASI (b = -0.41, p = 0.002) and AIx (b = -0.49, p < 0.001), and AIx@75 (b = -0.54, p < 0.001) which remained significant after adjustments for age, sex, and body mass index, mean blood pressure, and heart rate only for AASI (b = -0.46, p = 0.028) and AIx@75 (b = -0.24, p- = 0.040). Handgrip strength was not associated with cfPWV (p > 0.05). Conclusion: Handgrip strength is negatively associated with AASI and AIx@75, but not with AIx and cfPWV in hypertensive patients.

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