The Decision-Making of High-Level Volleyball Setters in the 2021-2022 Volleyball Men's Superliga: Does the Opponent Matter?

Our primary objective in this study was to investigate the offensive strategies employed in the attack phase of men's volleyball, specifically focusing on side-out as stratified by the type of confrontation that was determined by the opponent's team performance. We analyzed 5524 attacking actions during 22 games of the 12 teams that participated in the Volleyball Men's Superliga (season 2021-2022). Based on their final rankings in the championship, we classified these teams into three tiers: high-performance, intermediate-performance, and low-performance. Subsequently, we examined the dynamics of these matches using Social Network Analysis. We found that the opponent teams' performance levels did not influence the game dynamics. Notably, the eigenvector values were prominently higher for Attack Zones 2 and 4, wherein the middle-blocker jumped to attack close to the setter across all networks. Thus, setters opted for traditional and low-risk strategies to minimize errors, disregarding available information about the skill level of the opposing team, making their offensive tactics predictable.

Upper and Lower Limbs Acute Fatigue Did Not Mitigate Male Trained Air Force Soldiers' Marksmanship.

In this study, we aimed to investigate the impact of acute fatigue on pistol shooting performance among Air Force marksmen. We compared the accuracy, precision, speed-accuracy trade-off, shooting cycle time, and hits on a silhouette target among 12 Brazilian Air Force servicemen (M age = 21.5, SD - 1.6 years) under both fatigue and non-fatigue conditions in a crossover design. In the fatigued condition, the participants performed a fatigue protocol composed of side runs, vertical jumps, push-ups, running, and burpees exercises before shooting. Participants performed the countermovement jump and the plyometric push-ups tests on a contact mat before and immediately after the fatigue protocol to compare the heights achieved pre- and post-fatigue. Paired t-tests showed a significant performance reduction of 34.36% and 40.02% for the countermovement jump and plyometric push-ups, respectively, indicating that participants were fatigued in their lower and upper limbs. In the non-fatigued condition, no exercise was performed before shooting. Results indicated no significant differences between conditions on shooting precision (p = .125; ES: .54), speed-accuracy trade-off (p = .261; ES = .33), hits within the silhouette (p = .167; ES = .41), or shooting cycle times (p = .868; ES = .05); but accuracy was greater (p = .025; ES: .54) when fatigued. We concluded that overall shooting performance was not impaired by physical fatigue, and shooting accuracy appeared to be improved. Perhaps physical fatigue was not enough to impair shooting accuracy in this young adult group, as accuracy decline is expected instead when shooters are in an exhausted state. Further research is needed to confirm these findings and test this presumption.

Resistance training intervention performed with different muscle action durations influences the maximal dynamic strength without promoting joint-angle specific strength gains.

The present study investigated the effect of 10-week matched (range of motion, volume, intensity, rest, and repetition duration) training protocols with varying muscle action duration (MAD) on maximal voluntary isometric contraction (MVIC) test at eight different knee angles and one-repetition maximum (1RM) test after in seated knee extensor machine. Forty women were allocated into one control and three training groups with varying MAD: 5C1E (5s concentric action [CON] and 1s eccentric action [ECC]), 3C3E (3s CON and 3s ECC), and 1C5E (1s CON and 5s ECC). All training groups (5C1E, 3C3E, and 1C5E) showed a greater relative response in 1RM performance than the control group (0.1 ± 3.5%, p ≤ 0.05). The 1C5E group presented greater relative increases in the 1RM performance (22.1 ± 11.6%) compared to 5C1E (13.6 ± 9.2%; p ≤ 0.05) and 3C3E (14.1 ± 5.5%, p ≤ 0.05) groups. The training groups increased the MVIC performance more than the control group (p ≤ 0.05), although there were no significant differences between the training groups. This study demonstrated that isoinertial resistance training protocols with shorter CON MAD showed greater maximum dynamic strength performance response than matched training protocols with other MAD configurations. However, the configuration of MAD did not induce angle-specificity to increase the maximum isometric strength.

Resistance training with different repetition duration to failure: effect on hypertrophy, strength and muscle activation.

BACKGROUND: This study investigated the effects of two 14-week resistance training protocols with different repetition duration (RD) performed to muscle failure (MF) on gains in strength and muscle hypertrophy as well as on normalized electromyographic (EMG) amplitude and force-angle relationships. METHODS: The left and right legs of ten untrained males were assigned to either one of the two protocols (2-s or 6-s RD) incorporating unilateral knee extension exercise. Both protocols were performed with 3-4 sets, 50-60% of the one-repetition maximum (1RM), and 3 min rest. Rectus femoris and vastus lateralis cross-sectional areas (CSA), maximal voluntary isometric contraction (MVIC) at 30o and 90o of knee flexion and 1RM performance were assessed before and after the training period. In addition, normalized EMG amplitude-angle and force-angle relationships were assessed in the 6th and 39th experimental sessions. RESULTS: The 6-s RD protocol induced larger gains in MVIC at 30o of knee angle measurement than the 2-s RD protocol. Increases in MVIC at 90o of knee angle, 1RM, rectus femoris and vastus lateralis CSA were not significant between the 2-s and 6-s RD protocols. Moreover, different normalized EMG amplitude-angle and force-angle values were detected between protocols over most of the angles analyzed. CONCLUSION: Performing longer RD could be a more appropriate strategy to provide greater gains in isometric maximal muscle strength at shortened knee positions. However, similar maximum dynamic strength and muscle hypertrophy gains would be provided by protocols with different RD.

The Effects of Altering the Concentric/Eccentric Phase Times on EMG Response, Lactate Accumulation and Work Completed When Training to Failure.

This study compared the electromyographic response, the blood lactate concentration (BLC), and the maximum number of repetitions (MNR) between protocols of different concentric/eccentric duration taken to muscle failure. This comparison may help to understand how different concentric/eccentric duration may influence performance and the central and metabolic responses in trained men. Seventeen strength-trained men performed two protocols in a counterbalanced design. Three sets of the Smith bench press exercise were performed to failure at 60% of the one-repetition maximum (1RM) using each protocol (4-s concentric/2-s eccentric [4 s: 2 s]; and 2-s concentric/4-s eccentric [2 s: 4 s]). The normalized root mean square (EMGRMS) and the mean frequency (EMGMF) of the electromyographic signals for the pectoralis major and the triceps brachii were compared in the first, middle, and last repetitions. The BLC was assessed at rest, during and after the test sessions. To compare the EMG and BLC, a 3-way ANOVA with repeated measures with a post hoc Tukey's test was used. To compare the MNR performed across the sets, an ANOVA-type rank test with the Dunn's post hoc test was used. The ANOVA indicated a greater EMGRMS for Protocol 4 s: 2 s in the pectoralis major and a lower EMGMF for Protocol 4 s: 2 s in the triceps brachii at the middle and last repetitions. Both protocols increased the EMGRMS and decreased the EMGMF across repetitions. Despite the results show different levels of activation and neuromuscular fatigue between protocols, the BLC and the MNR were similar.

Análise do ataque do jogador de ponta no voleibol brasileiro masculino

RESUMO Este estudo objetivou identificar e analisar as chances de ocorrerem os efeitos dos ataques feitos pelos atacantes de ponta, a partir das posições 4 e 6, no side-out, segundo o efeito da recepção, tempo de ataque e o tipo de ataque. Foram analisados 142 jogos da Superliga Masculina 2014-2015, total de 6.185 ações de ataque. Os pontos de ataque foram predominantes após as recepções de excelente qualidade e os ataques potentes. Houve diferença no efeito da recepção, tipo de ataque e efeito do ataque, segundo o local da finalização (x2=33,68; p<0,001). Os ataques de ponta se caracterizaram por serem feitos após recepções que permitem o ataque organizado e pela potência do ataque. O local de ataque mostrou-se como diferenciador do tipo de ataque feito, sugeriu que as restrições ambientais exigem do atacante de ponta comportamento distinto em função do local da finalização.

ABSTRACT This study aimed to identify and analyse the chances to occur of the attack effects carried out from positions 4 and 6, the left-side attackers, in the side-out, according to the reception effect, attack tempo and attack type. It was analyzed 142 games of the 2014-2015 Men's Superleague, totaling 6185 attacks. The points of attack were predominant by the reception of excellent quality and the powerful attacks. There was difference in the effect of the reception, attack type and attack effect, according to the place of (x2=33,68; p<0,001). Attacks for zone 4 and 6 were characterized by being performed after receptions that allow the organized attack and the power of the attack. The attack place proved to be a differentiator of the attack type carried out, suggesting that the environmental restrictions require the attacker to behave differently according to the place of attack.

RESUMEN El objetivo de este estudio fue identificar y analizar las posibilidades de que se produjeran los efectos de los ataques feitos por los atacantes de punta, a partir de las posiciones 4 y 6, en el side-out, según el efecto de la recepción, tiempo de ataque y tipo de ataque. Se analizaron 142 partidos de la Superliga Masculina 2014-2015, con un total de 6.185 ataques. Dominaron los puntos de ataque después de la recepción de buena calidad y los ataques fuertes. Hay diferencia en la recepción, el tipo del ataque y el efecto del ataque según el lugar de la finalización (x2=33,68; p<0,001). Los ataques de punta se caracterizaron por su realización después de las recepciones que permitían el ataque organizado y por la fuerza del ataque. El lugar de ataque es un diferenciador del tipo de ataque feito y las restricciones ambientales exigen del atacante de punta un comportamiento diferente en función del lugar de la finalización.

Efeito de três protocolos de treinamento na pressão arterial e frequência cardíaca em normotensos / Effect of three training protocols on blood pressure and heart rate in normotensive men

INTRODUÇÃO: Doenças cardiovasculares representam a principal causa de morte no Brasil, sendo uma destas a hipertensão arterial. A prática regular de exercício físico permite um melhor controle da pressão arterial e indivíduos com maiores níveis de aptidão física apresentam um menor risco para desenvolver hipertensão. Além disso, pessoas com frequências cardíacas de repouso mais baixas apresentam uma menor probabilidade de desenvolverem cardiopatias. OBJETIVO: Comparar o efeito do treinamento aeróbico, de força e combinado nas pressões arteriais sistólica, diastólica e média e na frequência cardíaca de repouso em homens normotensos. MÉTODOS: Ensaio clínico aleatorizado com três grupos experimentais e um grupo controle. Cada grupo experimental realizou uma destas três modalidades de treinamento, três vezes por semana, durante doze semanas. Participaram homens de 30 a 57 anos, sedentários e normotensos. A pressão arterial e a frequência cardíaca pré e pós intervenção foi aferida utilizando um aparelho automático validado e seguindo recomendações da Sociedade Brasileira de Cardiologia. Os dados foram comparados pelo teste t de Student e pela ANOVA one-way. RESULTADOS: 39 voluntários completaram o estudo. Não houve variação significante da pressão arterial sistólica, diastólica e média e frequência cardíaca nos três grupos de treinamento entre pré e pós-intervenção. Apenas a frequência cardíaca nestes grupos apresentou diferenças significativas quando comparada ao grupo controle. CONCLUSÃO: Resultados sugerem que o treinamento físico, realizado três vezes por semana, durante doze semanas, não é suficiente para reduzir a pressão arterial de modo significativo em homens normotensos, seja este treinamento aeróbico, de força ou combinado.

INTRODUCTION: Cardiovascular diseases are the most common cause of death in Brazil and one of these diseases is hypertension. Regular practice of physical exercise may contribute to a better control of blood pressure and individuals with higher levels of physical fitness have lower risk for developing hypertension. In addition, people with lower heart rate have lesser likelihood for developing cardiovascular diseases. OBJECTIVE: Compare the effect of aerobic, strength and combined training on systolic, diastolic and mean blood pressure and at the resting heart rate in normotensive men. METHODS: A randomized trial with three experimental groups and one control group was conducted. Each experimental group practiced a determined type of training, three times per week during, twelve weeks. Men aged 30 to 57 years, sedentary and normotensive participated in this study. Blood pressure and heart rate values were checked at pre and post-intervention in all four groups by using a validated automatic device as recommend the Brazilian Cardiologic Society. The data were compared by Student's t test and by ANOVA one-way. RESULTS: 39 participants completed the study. There was no significant variation of systolic, diastolic and mean blood pressure and at the resting heart rate in the three experimental groups between pre and post-intervention. However, only heart rate in three training groups showed differences when compared to the control group. CONCLUSION: The results suggest aerobic, strength or combined training when performed as in this study did not change blood pressure significantly in normotensive men.

A prior isometric strength training increases muscle power performance of judo athletes / Exercício preparatório de força isométrico aumenta o desempenho de potência muscular de judocas

ABSTRACT Muscular power, a determinant in judo fights, can be developed by high intensity strength exercises through a mechanism known as post-activation potentiation. Thus, the objective of the present study is to verify the effect of isometric squat exercise on the performance of judo athletes. The sample was made up of eight judo athletes (22.3 ± 3.5 years old, 166.0 ± 6.0 cm; 65.4 ± 7.0 kg). The subjects went through four days of tests, one familiarization session, another as a control situation and two others as experimental sessions. In the experimental sessions, exercises in a Smith squat machine prior to the vertical countermovement jump (CMJ) test and a Special Judo Fitness Test (SJFT). In the control session, only SJFT was performed. Student's t test for paired samples was used to compare performances in the different situations. A significant increase was observed in the number of projections in the SJFT (25.5 ± 2.2 vs. 26.8 ± 2.2 projections) after MVIC and in the height in CMJ (31.0 ± 2.2 vs. 33.3 ± 2.2 cm). The MVIC exercise protocol performed as a preparatory activity increased the performance of judo athletes in judo-specific tests/SJFT and CMJ.

RESUMO A potência muscular, determinante nas lutas de judô, pode ser desenvolvida por exercícios de força de alta intensidade através de um mecanismo conhecido como potenciação pós-ativação. Sendo assim, o objetivo do presente estudo é verificar o efeito do agachamento em isometria no desempenho de judocas. A amostra foi composta por oito judocas (22,3 ± 3,5 anos; 166,0 ± 6,0 cm; 65,4 ± 7,0 kg). Foi realizado quatro dias de testes, uma para sessão de familiarização, uma para a situação controle e duas para sessões experimentais. Nas sessões experimentais foi testado o efeito do exercício de agachamento guiado em contração voluntária isométrica máxima (CVIM) no desempenho do Special Judo Fitness test (SJFT) e do salto vertical com contra movimento (SCM). Na sessão controle foi realizado apenas o SJFT. O teste T Student pareado foi utilizado para comparar o desempenho entre as diferentes situações. Após a execução da CVIM foi observado um aumento significativo no número de arremessos no teste SJFT (25,5±2,2 vs. 26,8±2,2 projeções) e na altura do SCM (31,0 ± 2,2 vs. 33,3±2,2 cm). O protocolo de exercício CVIM realizado como atividade preparatória aumentou o desempenho de atletas de judô em teste específicos do Judô / SJFT e de SCM.

Visual behavior and the quality of decision-making on volleyball / Comportamento visual e qualidade da tomada de decisão no voleibol

Abstract This study aims to verify the visual behavior using the analysis of both quantity and duration of visual fixation and the quality of the DM in volleyball players and athletes from other sports in extreming attacking (EA), cental attack (CA), setting (SE) and blocking (BL) situations. The visual behavior was analyzed during the evaluation of volleyball scenes with an eye-tracking system. The first decision the volunteer voiced was determined as his solution for the scene presented and it was used for analyzing the DM quality. For the quantity of visual fixations, the independent t-test was used to compare groups in the following situtations, EA, SE and BL. For analyzing the quality of DM, the chi-square test of proportions was used. Moreover, for the analysis of the duration and number of visual fixations, the independent t test was addopet (or Mann-Whitney test when some of the assumptions were not met for parametric analysis). Significantly higher values were observed on duration of visual fixations in athletes from other sports comparing to volleyball players at CA (p = 0.042). The DM were significantly different in EA (p = 0.024) and CA (p = 0.001) between groups, showing higher frequency of correct answers for the volleyball players. We conclude that volleyball players perform faster fixations in situations of CA and take more correct decisions in attacking situation (EA and CA) compared to athletes from other sports.

Resumo Objetivou-se verificar o comportamento visual através da análise da quantidade e duração da fixação visual e a qualidade da TD em jogadores de voleibol e atletas de outros esportes nas situações de ataque de extremidade (AE), ataque de central (AC), levantamento (LE) e bloqueio (BL). Analisou-se o comportamento visual durante a avaliação de cenas de voleibol com o eye-tracking (sistema de rastreamento ocular). A primeira decisão do voluntário verbalizada foi considerada como a sua solução para a cena apresentada e foi utilizada para analisar a qualidade da TD. Para a quantidade de fixações visuais, o teste t independente foi utilizado para comparar os grupos nas seguintes situações, AE, LE e BL. Para a análise da qualidade da TD, utilizou-se o teste qui-quadrado de proporções. Já para a análise da duração e número de fixações visuais recorreu-se ao teste t independente (ou teste de Mann-Whitney quando algum dos pressupostos para a análise paramétrica não foi atendido). Valores significativamente maiores foram encontrados na duração das fixações visuais em atletas de outros esportes quando comparados a atletas de voleibol no AC (p=0,042). As TD foram significativamente diferentes em AE (p=0,024) e AC (p=0,001) entre os grupos, motrando maior frequência de respostas corretas para os atletas de voleibol. Conclui-se que os atletas de voleibol realizam fixações mais rápidas em situações de AC e tomam decisões mais corretas em situações de ataque (AE e AC) em comparação com os atletas de outros esportes.