Effects of Eccentric Phase Velocity on Bench Press Concentric Bar Velocity in the Young and Elderly.

This study aimed to investigate the impact of bar velocity during the eccentric phase on subsequent concentric performance in the young and elderly. Twelve elderly women (65.2+4.2 years) and 16 young women (23.1+2.1 years) were randomly assigned to four experimental conditions that combined high-velocity eccentric actions (HVECC; maximum velocity) and moderate-velocity eccentric actions (MVECC; 2.0 s), using 30% and 60% of their 1-repetition maximum (1RM) on the Smith machine bench press. Measurements of mean propulsive velocity (MPV), peak velocity (PV), and mean power (MP) were recorded. Two-way ANOVA with repeated measures was applied for each variable, when needed, the Bonferroni post hoc was used. Statistical significance was set at p<0.05, and effect size (ES) was established by Cohen's d z. The results demonstrated that elderly women showed improved performance in MPV (+10.0%; ES=- 0.58; p=0.009) and MP (+11.7%; ES=- 0.14; p=0.045) when utilizing HVECC at 30% 1RM only. Moreover, young women exhibited superior performance for both 30% and 60% 1RM when using HVECC for all variables analyzed (p<0.05). The HVECC appears to have an impact on the subsequent performance of the concentric phase, particularly when lighter loads (30% 1RM) are utilized, regardless of the age group.

Reply to Gurney, T.; Ronca, F. Comment on "Hack et al. Effect of Guarana (Paullinia cupana) on Cognitive Performance: A Systematic Review and Meta-Analysis. Nutrients 2023, 15, 434".

We thank Dr. Gurney for his interest and comment [...].

Effects of lower and upper body fatigue in striking response time of amateur karate athletes.

In combat sports, strikes or counter-strikes response time (RT) can be related to performance and sporting success. Moreover, training sessions are usually highly fatiguing, which is expected to impair basic skills, such as RT. Thus, this study aimed to investigate the effect of fatigue on punch and kick RTs of karate practitioners. Twelve individuals of both sexes from different levels (three yellow belts, three red belts, two orange belts, two green belts, one brown belt, and one black belt) were selected. Participants were aged 22 ± 3 years old, with a stature of 169.1 ± 6.5 cm, and a body mass of 65.5 ± 10 kg. Six visits were held with each participant. On the first 2 days, the RT of punches and kicks was measured by a validated smartphone app (TReaction). For the subsequent visits, a randomized incremental test for the upper or lower body was adopted as motor fatigue protocol, immediately followed by punches and kicks RT tests, also in random order. For induction of lower and upper body-specific muscle fatigue, the ITStriker app was used, which operates by emitting sound signals transmitted by a smartphone. One-way repeated measures ANOVA was performed, and significance was set at p ≤ 0.05. Regarding the mean punches RT, significant effects between situations for the upper (F(2,22) = 11.5; ω2 = 0.23; p < 0.001) and lower body (F(2,22) = 14.2; ω2 = 0.18; p < 0.001) fatigue protocols were found. The negative effect of the lower body fatigue protocol in punches RT was evident regardless of the order of the tests (punch RT first: Δ = 10.5%; t = 4.4; p < 0.001; d = 1.0; kick RT first: Δ = 11.4%; t = 4.8; p < 0.001; d = 1.1). Regarding mean kicks RT, significant effects were found between situations for the lower (F(2,22) = 16.6; ω2 = 0.27; p < 0.001) but not for the upper (F(2,22) = 2.3; ω2 = 0.02; p = 0.12) body fatigue protocols. Kick RTs were negatively affected by the lower body fatigue protocol regardless of the RT order applied (punch RT first: Δ = 7.5%; t = 3.0; p = 0.01; d = 0.8; kick RT first: Δ = 14.3%; t = 5.7; p < 0.001; d = 1.5). Upper body fatigue does not impair punch or kick RTs. Thus, it is concluded that the specificity of fatigue protocols and striking order should be considered while performing RT demanding techniques in karate practice. Specifically, lower body motor fatigue may impair both kicks and punches RT, which highlights the role of lower limbs in punches performance. Otherwise, upper body motor fatigue seems to induce impairments that are limited to the specific motor actions of this body segment.

Effect of Guarana (Paullinia cupana) on Cognitive Performance: A Systematic Review and Meta-Analysis.

The plant extract guarana is known for its caffeine content and other bioactive ingredients, which purportedly may improve cognitive performance. Recent reviews have examined the effects of chronic supplementation of guarana in clinical populations; however, the acute effects of guarana on cognitive tasks, while of interest, have produced mixed results. Whether acute guarana ingestion improves human cognitive performance was assessed by performing a systematic review coupled with a meta-analysis. Eight placebo-controlled studies were identified and met the inclusion criteria providing data on 328 participants. The dose of guarana (37.5 to 500 mg) with reported caffeine content (4.3 to 100 mg) varied. Effect sizes (ESs) were calculated as the standardized mean difference and meta-analyses were completed using a random-effects model. The ESs for guarana averaged across a variety of cognitive measures and outcome variables were less than trivial (Hedge's g = 0.076, p = 0.14). Using a subgroup meta-analysis (Q = 12.9, p < 0.001), ESs indicating a faster response time for guarana vs. a placebo (g = 0.202, p = 0.005) differed from the accuracy measures (g = −0.077, p = 0.4) which were non-significant. For response time, guarana ingested in a capsule (g = 0.111) tended to differ (Q = 2.96, p = 0.085) compared to guarana when dissolved in liquid (g = 0.281). Meta-regression of the study ESs of overall cognitive task performance was not related to the guarana dose (R2 < 0.001) or to the time allowed prior to cognitive testing (R2 < 0.001). Acute guarana ingestion had a small effect on the response time (faster performance) during a variety of cognitive tasks without affecting the accuracy. Whether the changes were linked to the caffeine content or other bioavailable substances in guarana is unknown. Additional studies that directly compare matched doses of caffeine versus guarana are needed to understand its effects on cognitive performance.

No Effects of Mental Fatigue and Cerebral Stimulation on Physical Performance of Master Swimmers.

Background: Mental fatigue is a psychobiological state caused by extended periods of cognitive effort, and evidence suggests that mentally fatigued athletes present impaired physical performance. Different ergogenic aids have been proposed to counteract the deleterious effects of mental fatigue, but whether brain stimulation can counteract mental fatigue is still unknown. This scenario is even more obscure considering the effects of these interventions (mental fatigue induction and brain stimulation) in a very experienced population consisting of master athletes. Method: Ten master swimmers (30 ± 6 years old and 14 ± 8 years of experience) participated in the study. They underwent four experimental conditions before an 800-m freestyle test: mental fatigue with brain stimulation; mental fatigue without brain stimulation; absence of mental fatigue with brain stimulation; and absence of mental fatigue and no brain stimulation. Mental fatigue was induced by a cognitively demanding Stroop Color Test, whereas stimulation was applied on the temporal cortex. After that, the athletes swan 800 m as fast as possible and provided their ratings of perceived exertion (RPE) every 200 m. Results: Mental fatigue was effectively induced, as evidenced by a greater fatigue perception and more errors in the last blocks of the cognitive task. Mental fatigue induction did not influence performance (time to complete the swimming trial) and RPE. Similarly, brain stimulation failed to change these two parameters, regardless of mental fatigue induction. Conclusion: The prolonged physical performance of experienced master athletes is not influenced, under the present conditions, by mental fatigue induction, cerebral stimulation, and their association.

Prevalence of burnout syndrome and perception by playing position in professional football players

Abstract Aim: The present study aimed to investigate the indicators of burnout, to determine whether playing position affects the perception of syndrome dimensions, and to identify burnout prevalence in professional football players. Methods: The participants were 100 professional football players (mean age 24.3 ± 4.6 years and meantime as a professional athlete of 9.2 ± 4.5 years) who were divided into three groups: 27 forwards, 34 midfielders, and 39 defenders. The Athlete Burnout Questionnaire (ABQ) and a sociodemographic questionnaire were applied. Results: The results show that a) the majority of athletes had low burnout indicators, b) there was no difference in the perception of burnout dimensions by playing position, and c) the prevalence of athletes with burnout, whether mild, moderate, or severe, was 13%. Conclusion: The variable of playing position was not a determinant of perception of burnout dimensions among the forwards, midfielders, and defenders. Nonetheless, the prevalence of burnout deserves attention, as the negative effects of this syndrome may exert impacts on health, well-being, and sports performance, making athletes more likely to abandon their sport.

Cluster-sets resistance training induce similar functional and strength improvements than the traditional method in postmenopausal and elderly women.

OBJECTIVE: The aim of this study was to compare the effects of 12 weeks of traditional resistance training (TRT) or resistance training using Cluster-set (CS) on functional performance and physical fitness of postmenopausal and elderly women. METHODS: Participants (61.1 ± 4.9 years, body mass 64.5 ± 1.8 kg, height 155.7 ± 4.7 cm) were randomized to TRT (n = 35) or CS (n = 31). Anthropometric measures, muscle strength and power, gait speed, core stability, flexibility, and functional performance tests were performed before and after 12 weeks of training. The difference between protocols was the structure of rest intervals. The TRT group performed 120 s of rest between sets of 8 repetitions, while the CS performed 30 s of rest after every 2 repetitions. Two-way ANOVA with repeated measures was applied for each variable and, when needed, the Bonferroni post hoc was used. Statistical significance was set at p < 0.05. RESULTS: No group by time interaction was found for any variable. Regarding between-moment comparisons, there were significant improvements for 1 repetition maximum (RM) bench press (F = 104.6; ηp2 = 0.62; p < 0.001), 1RM leg press (F = 74.6; ηp2 = 0.53; p < 0.001), medicine ball throw (F = 64.0; ηp2 = 0.26; p < 0.001), standing long jump (F = 27.6; ηp2 = 0.30; p < 0.001), countermovement jump (F = 17.4; ηp2 = 0.21; p < 0.001), squat jump (F = 23.2; ηp2 = 0.26; p < 0.001), plank time (F = 31.6; ηp2 = 0.33; p < 0.001), 6 m walking test (F = 18.0; ηp2 = 0.22; p < 0.001), sit-to-stand test (F = 20.4; ηp2 = 0.24; p < 0.001), sit and reach test (F = 56.8; ηp2 = 0.47; p < 0.001) and 2 kg elbow curls (F = 15.9; ηp2 = 0.19; p < 0.001). CONCLUSION: Considering that both CS and TRT methods were equally effective to improve the physical fitness and functionality of elderly women, the decision of which protocol to use should be based on individual preferences and practical aspects.

Short-Duration Beta-Alanine Supplementation Did Not Prevent the Detrimental Effects of an Intense Preparatory Period on Exercise Capacity in Top-Level Female Footballers.

Purpose: High-intensity activity is an important aspect of football performance during competitive match play. The aim of this study was to investigate the effect of beta-alanine supplementation throughout a short-duration intense football-specific training period prior to an international competition on measures of high-intensity running performance. Methods: Twenty-four elite international U20 female footballers (age 18 ± 1 y, height 1.67 ± 0.07 m, body mass 62.7 ± 7.4 kg) volunteered to perform the YoYo Intermittent Recovery Test Level 1 (YoYo IR1), the Running Anaerobic Sprint Test (RAST) and a 20-m maximal sprint test on two separate occasions, separated by 3 weeks of training and supplementation. Participants were randomly assigned to receive either 6.4 g·day-1 sustained-release beta-alanine (BA, N = 12) or an equivalent dose of maltodextrin (placebo, PL, N = 12) throughout a 3-week standardized training camp. Results: There was a main effect of group (P = 0.05) and time (P = 0.004) on YoYo IR1; overall values were lower in PL and distance covered was lower post- vs. pre-supplementation. There was no group × time interaction (P = 0.07). There was an effect of sprint number for RAST, but no further main effects and there were no effect for the 20-m sprint. Conclusions: Top-level female footballers involved in this intense 3-week training period prior to a competition worsened their high-intensity intermittent exercise capacity, and this negative result was not attenuated by a short-duration BA supplementation protocol throughout the same period. Further work is necessary to elucidate whether adapted training protocols and BA dosing regimens could lead to better results.

Resiliência em atletas de Artes Marciais Mistas: Relação entre estressores e fatores psicológicos de proteção / Resiliencia em atletas de Artes Marciales Mixtas: Relación entre estressores y factores psicológicos de protección / Resilience in Mixed Martial Arts Athletes: Relationship between stressors and psychological protection factors

Lidar com situações impostas em treinamentos e competições e saber administrá-las emocionalmente é essencial para que atletas apresentem um desempenho elevado. Estudos apontam que atletas resilientes apresentam a capacidade de enfrentar e interpretar positivamente situações adversas. Esta pesquisa tem como objetivo investigar a dinâmica do processo de resiliência em atletas profissionais de MMA. A amostra desse estudo foi constituída por 10 atletas brasileiros. O instrumento utilizado foi um roteiro de entrevista semiestruturada, tendo como base a teoria fundamentada da resiliência psicológica e ótimo desempenho esportivo. Os resultados constataram que o processo de resiliência pode ocorrer quando os fatores internos (próprios do indivíduo) e fatoresexternos (como o ambiente e as relações sociais) se interagem, produzindo respostas favoráveis mesmo em situações provedoras de estresse da modalidade

Luchar con situaciones impuestas en competiciones y entrenamientos y saber administrarlas emocionalmente es esencial para que los atletas presenten un buen resultado en competiciones. Los estudios apuntan a la resiliencia como un fenómeno que ejerce capacidad de enfrentar e interpretar positivamente situaciones adversas. Esta investigación tiene como objetivo general investigar la dinámica del proceso de resiliencia en atletas profesionales de MMA y como objetivos específicos analizar las fuentes de estrés y los aspectos psicológicos de protección al atleta. La muestra de este estudio fue constituida por 10 atletas brasileños. El instrumento utilizado fue un guión de entrevista semiestructurada, teniendo como base la teoría fundamentada de la resiliencia psicológica y óptimo desempeño deportivo. Los resultados de este estudio constataron que la dinámica del proceso de resiliencia puede ocurrir cuando los factores internos propios del individuo y también factores externos como el ambiente y las relaciones sociales, vivenciados por los atletas se interactúan, produciendo respuestas favorables incluso en las situaciones proveedoras de estrés de la modalidad

Dealing with situations imposed in training and competitions and knowing how to administer them emotionally is essential for athletes to present an optimal performance. Studies point to resilience as a phenomenon that exerts the capacity to face and interpret positively adverse situations. This research aims to investigate the dynamics of the resilience process in professional athletes of MMA and as specifics objectives to analyze the sources of stress and psychological aspects of protection to the athlete. The sample of this study consisted of 10 athletes from Brazil. The instrument used was a semi-structured interview script, based on the theory of psychological resilience and optimal sports performance. The results of this study showed that the dynamics of the resilience process can occur when the internal factors of the individual and also external factors such as the environment and the social relations experienced by the athletes interact, producing favorable responses even in the stressful situations of the modality

Dimensões de Burnout, Estratégias de Coping e Tempo de Prática como Atleta Federado em Jogadores Profissionais de Futebol / Dimensiones de Agotamiento, Estrategias de Afrontamiento y Tiempo de Práctica como Atleta Federado en Jugadores Profesionales de Fútbol / Burnout Dimensions, Coping Strategies and Practice Time as a Federated Athlete in Professional Soccer Players

O objetivo do estudo consiste em analisar se há correlação entre as seguintes variáveis emjogadores profissionais de futebol: a) dimensões de burnoutx estratégia de coping; b) tempo de prática como atleta federado x dimensões de burnout; c) tempode prática como atleta federado x estratégias de coping. Participaram do estudo 54 atletas profissionais de futebol da primeira divisão do Campeonato Paraense de 2018, todos do sexo masculino. A média de idade foi de 24.0 ± 3.9 anos, e a média do tempo deprática como atleta federado foi de 8.7 ± 4.2 anos. Os participantes responderam a dois instrumentos psicométricos de mensuração de burnoute coping. Os resultados evidenciam que: I) os indicadores de burnoutforam baixos; II) a correlação entre as dimensões de burnoute copingfoi significativa, negativa e moderada somente entre a dimensão reduzido senso de realização esportiva e a estratégia treinabilidade; III) não observamos correlação entre o tempo de prática como atleta federado e as dimensões de burnout; IV) encontramos uma correlação significativa, positiva e moderada entre o tempo de prática como atleta federado e a estratégia desempenho sob pressão. As principais conclusões do estudo apontam que atletas com maior tempo de prática como federados tendem a apresentar melhor desempenho sob pressão, bem como o desenvolvimento da estratégia treinabilidade pode ser oportuno para a percepção de realização esportiva em atletas

El objetivo del estudio consiste en analizar si hay correlación entre las siguientes variablesen jugadores profesionales de fútbol: a) dimensiones de agotamiento x estrategia de afrontamiento; b) tiempo de práctica como atleta federado x dimensiones de agotamiento; c) tiempo de práctica como atleta federado x estrategias de afrontamiento. Participaron del estudio 54 atletas profesionales Brasileños de fútbol de la primera división del Campeonato Paraensede 2018, todos del sexo masculino. El promedio de edad fue de 24.0 ± 3.9 años, y el promedio del tiempo de práctica como atleta federado fue de 8.7 ± 4.2 años. Los participantes respondieron a dos instrumentos psicométricos de medición de agotamiento y afrontamiento. Los resultados evidencian que: I) los indicadores de agotamiento fueron bajos; II) la correlación entre las dimensiones de agotamientoy afrontamiento fue significativa, negativa y moderada solamente entre la dimensión reducido sentido de realización deportiva y la estrategia de capacitación; III) no observamos correlación entre el tiempo de práctica como atleta federado y las dimensiones de agotamiento; IV) encontramos una correlación significativa, positiva y moderada entre el tiempo de práctica como atleta federado y la estrategia de rendimiento bajo presión. Las principales conclusiones del estudio apuntan que los atletas con mayor tiempo de práctica como federados tienden a presentar mejor desempeño bajo presión, así como el desarrollo de la estrategia de capacitación puede ser oportuno para el sentido de realización deportiva en atletas

The objective of the study is to analyze whether there is correlation between the following variablesin professional soccer players: a) burnout dimensions x copingstrategies; b) practice time as a federated athlete x burnoutdimensions; c) practice time as a federated athlete x copingstrategies. Fifty-four professional Brazilian soccer athletes from the first division of the 2018 ParáState Championship, all males, participated in the study. The mean age was 24.0 ± 3.9 years, and the mean time of practice as a federated athlete was 8.7 ± 4.2 years. Participants responded to two paper and pencil psychometric instruments measuring burnoutand coping. The results show that: I) the burnoutindicators were low; II) the correlation between the dimensions of burnoutand copingwas significant, negative and moderate only between the dimension reduced sense of accomplishment and the strategy of coachability; III) we did not observe correlation between the time of practice as a federated athlete and the dimensions of burnout; IV) we found a significant, positive and moderate correlation between the practice time as a federated athlete and the strategy performance under pressure. The main conclusions of the study point out that athletes with higher practice time as federated tend to present better performance under pressure, as well as the development of the strategy coachability may be opportune for athletes' sense of accomplishment

Relação entre o potencial esportivo de jovens alunos-atletas e coping / Relationship between the sports potential of young student-athletes and coping / Relación entre el potencial deportivo de jóvenes alumnos-atletas y coping

Analisar diferenças nas habilidades de copingentre os sexos e o potencial esportivo de alu-nos-atletas de um colégio militar. Trezentos e oitenta e cinco alunos-atletas responderam o ACSI-28BR. O potencial esportivo foi avaliado pelos treinadores, sendo classificado como baixo e alto. Os meninos apresentaram maiores habilidades de copingdo que as meninas. Os meninos de alto potencial esportivo apresentaram maior confiança/motivação, treinabilidade e recurso total de coping, enquanto que as meninas de alto potencial apresentaram maior me-tas/preparação mental, concentração, confiança/motivação e recurso total de coping. Conclui-se que as habilidades psicológicas de copingsão maiores em alunos-atletas com alto potencial esportivo, variando entre meninos e meninas.

This study analyzes differences in the coping skills between sexes and the sporting potential of student-athletes of a military college. A total of 385student-athletes answered the ACSI-28BR. The sporting potential was evaluated by coaches, being classified as low and high. Males had higher coping skills than females. Males of high sporting potential showed higher confidence/motivation, trainability andtotal coping resources; while females with high potential had higher goals/mental preparation, concentration, confidence/motivation and total cop-ing resources. It is concluded that the coping psychological skills are higher in student-athletes with high sporting potential and vary between males and females.

Analizar diferencias en las habilidades de copingentre lossexos y el potencial deportivo de alumnos-atletas de un colegio militar. 385 alumnos-atletas respondieron el ACSI-28BR. El potencial deportivo fue evaluado por los entrenadores, siendo clasificado como bajo y alto. Los niños presentaron mayores habilidades de copingque las niñas. Los niños de alto poten-cial deportivo presentaron mayor confianza/motivación, capacitación y recurso total de co-ping; mientras que las niñas de alto potencial presentaron mayores metas / preparación men-tal, concentración, confianza/motivación y recurso total de coping. Se concluye que las habi-lidades psicológicas de copingson mayores en alumnos-atletas con alto potencial deportivo, variando entre niños y niñas.

What pacing strategy 800m and 1500m swimmers use? / Qual estratégia de prova que nadadores de 800m e 1500m usam?

Abstract Pacing strategy (PS) has a decisive impact on performance, especially on long-term races.The objective of this study is to characterize the PS used in swimming races of 800m and 1500m freestyle by the finalists of the Olympic trials of the United States, Europe and Brazil,and the Olympic finalists of 2016.Time partials of 63 athletes were analyzed using a decision tree and the CHAID method. The results showed that parabolic was adopted by swimmers of 800m, they start in first lap (29.67 ± 0.88 s), followed by an increase in time (+1.77 s) and a subsequent increase in time (32.04 ± 0.89 s), at the end, the swimmers presented an acceleration,reducing the average of the to 31.44 s. And by the free 1500m swimmers, divided into blocks with a faster average start (29.25 ± 1.15 s), half of the slowest race (30.30 ± 0.76 s), and a new acceleration at the end of the event (29.92 ± 1.12 s), both in the selective Olympic Games and the 2016 and 2016 Olympic final.The worst partials times were observed in the Brazilian Selective (Test Event) (31.11 ± 0.78 s). Medalist, despite presetting the same OS, can sustain a better rhythm throughout he 800m (31.52 ± 1.03 s) and 1500-m (29.80 ± 0.78). We conclude that parabolic PS is the optimal strategy adopted by swimmers of 800-m and 1500m freestyle.

Resumo A estratégia de prova (EP) tem impacto determinante no desempenho esportivo, principalmente em provas de longa duração. O objetivo foi caracterizar a EP utilizada em provas de natação de 800m e 1500m livre por finalistas das seletivas olímpicas dos Estados Unidos, Europa, Brasil e finalistas olímpicos de 2016. As parciais de tempo de 63 atletas foram analisadas por meio de árvore de decisão, utilizando o método CHAID. Os resultados mostraram que a EP parabólica foi adotada pelas nadadoras de 800m, com início (29.67 ± 0.88 s) seguido de um aumento de tempo (+1.77 s) e posterior novo aumento de tempo (32.04 ± 0.89 s), ao término as atletas apresentaram uma aceleração reduzindo a média para próximo à 31.44 s. E pelos atletas de 1500m livre, divididos em blocos com média inicias mais rápidas (29.25 ± 1.15 s), meio da prova mais lento (30.30 ± 0.76 s) e nova aceleração ao final da prova (29.92 ± 1.12s), tanto nas seletivas olímpicas quanto na final olímpica de 2016. Os piores tempos das parciais foram observados na seletiva olímpica do Brasil (evento teste) (31.11 ± 0.78 s). Atletas medalhistas, apesar de apresentarem a mesma EP, conseguem sustentar um melhor ritmo ao longo da prova de 800m (31.52 ± 1.03 s) e 1500-m (29.80 ± 0.78). Conclui-se que a EP parabólica é a estratégia ótima adotada pelos nadadores de 800m e 1500m.

Mental fatigue does not affect heart rate recovery but impairs performance in handball players / Fadiga mental não altera a recuperação da frequência cardíaca, mas afeta o desempenho de jogadores de handebol / Fatiga mental no varía la reparación de frecuencia cardiaca y muda el rendimiento en balonmano

INTRODUCTION: This study involved an analysis of the impact of mental fatigue on heart rate recovery (HRR), subjective measures of fatigue and intermittent running performance in handball players. OBJECTIVE: This study was aimed at (1) examining the effects of an induced state of mental fatigue on the aerobic performance of handball players, as measured by the Yo-Yo IR1 test, and (2) exploring possible changes in heart rate regulation through HRR analysis. METHODS: Twelve handball players (age: 17.50 ± 3.63 years; 5 ± 2.2 years of practice) undertook a Yo-Yo IR1 test on two occasions, separated by an interval of at least 72 hours. The Yo-Yo IR1 test was preceded by a 30-min treatment, consisting of the Stroop Color-Word Test, to induce mental fatigue. Participants in the control condition watched an emotionally neutral video. RESULTS: Higher ratings of mental fatigue and mental effort following the Stroop Test were observed for the experimental group. No differences in motivation were observed between conditions. Moreover, the induction of mental fatigue impaired running performance and led to a higher RPE during the Yo-Yo IR1 test. Notwithstanding, no changes in HRR or blood lactate levels were observed across conditions. CONCLUSION: Altogether, these results suggest that mental fatigue impairs intermittent running performance, without affecting HRR values. Level of Evidence III; Case-Control study.

INTRODUÇÃO: Este estudo envolveu uma análise do impacto da fadiga mental sobre a recuperação da frequência cardíaca (RFC), medidas subjetivas de fadiga e desempenho de corrida intermitente em jogadores de handebol. OBJETIVO: Este estudo visou (1) examinar os efeitos de um estado induzido de fadiga mental no desempenho aeróbico de jogadores de handebol, medido pelo teste Yo-Yo IR1 e (2) explorar possíveis alterações na regulação da frequência cardíaca através da análise da RFC. MÉTODOS: Doze jogadores de handebol (idade: 17,50 ± 3,63 anos, 5 ± 2,2 anos de prática) realizaram um teste Yo-Yo IR1 em duas ocasiões, com pelo menos 72 horas de intervalo. O teste Yo-Yo IR1 foi precedido por tratamento de 30 minutos que consistiu no teste Stroop Color-Word para induzir estado de fadiga mental. Os participantes na condição de controle assistiram a um vídeo emocionalmente neutro. RESULTADOS: Foram observadas taxas mais elevadas de fadiga mental e esforço mental após o teste Stroop para o grupo experimental. Não foram observadas diferenças na motivação entre as condições. Além disso, a indução de fadiga mental prejudicou o desempenho de corrida e levou a maior PSE durante o teste Yo-Yo IR1. Não obstante, não foram observadas alterações na RFC nem nas concentrações de lactato sanguíneo entre as condições. CONCLUSÃO: Em conjunto, esses resultados sugerem que a fadiga mental afeta o desempenho de corrida intermitente, sem alterar os valores de RFC. Nível de Evidência III; Estudo de caso-controle.

INTRODUCCIÓN: En el presente estudio se analizó el impacto de la fatiga mental en la recuperación de la frecuencia cardíaca (RFC), las medidas subjetivas de fatiga y el rendimiento intermitente en atletas de handball. OBJETIVO: los objetivos de este estudio fueron (1) examinar los efectos de un estado inducido de fatiga mental en el rendimiento aeróbico de atletas de handball, medida por el Yo-Yo IR1, y (2) explorar las posibles alteraciones en la regulación de la frecuencia cardíaca a través del análisis RFC. MÉTODOS: Doce atletas (edad: 17,50 ± 3,63 años, 5 ± 2,2 años de práctica) realizaron un test Yo-Yo IR1 en dos ocasiones, separados por un intervalo de al menos 72 horas. El test Yo-Yo IR1 fue precedido por un tratamiento de 30 minutos, consistente en el Stroop Color-Word Test, para inducir un estado de fatiga mental. Los participantes en la condición de control asistieron un video emocionalmente neutro. RESULTADOS: Se observaron altas percepciones de fatiga y esfuerzo mental después del test de Stroop para el grupo experimental. No se observaron diferencias de motivación entre las condiciones. Además, la inducción de fatiga mental perjudicó el desempeño de carrera y llevó a un mayor PSE durante el test Yo-Yo IR1. No obstante, no se observaron alteraciones en la RFC y en las concentraciones de lactato sanguíneo entre las condiciones. CONCLUSIÓN: En conjunto, estos resultados sugieren que la fatiga mental afecta el rendimiento intermitente de la carrera, sin alterar los valores de FCR. Nivel de Evidencia III; Estudio de caso-control.

Mental Fatigue Impairs Physical Performance in Young Swimmers.

PURPOSE: This study aimed to investigate the impact of mental fatigue on heart rate variability, subjective measures of fatigue, and swimming performance in young athletes. METHODS: Sixteen swimmers [15.45 (0.51) y old, 7.35 (2.20) y of swimming experience] performed a 1500-m time trial on 2 occasions separated by an interval of at least 72 hours. The 1500-m swimming was preceded by a 30-minute treatment that consisted of performing the Stroop Color and Word test to induce mental fatigue (experimental trial) or watching an emotionally neutral video (control trial). RESULTS: Participants reported higher ratings of mental fatigue and mental effort following the Stroop test when compared with the control trial, but no differences in motivation were observed. The induction of mental fatigue impaired swimming performance, as evidenced by a slower time (1.2%) to complete the 1500-m trial. No intertrial differences were identified for rating of perceived exertion during the swimming test or in heart rate variability after the Stroop and swimming tests. CONCLUSION: The results indicate that induction of mental fatigue impairs 1500-m swimming performance without changing heart rate variability.

The relative age effect on brazilian elite volleyball / O efeito da idade relativa no voleibol brasileiro de elite

ABSTRACT The relative age effect (RAE) refers to the advantage of the athletes born on the first months of the sport selection period compared to those born months later during such a selection process, which tends to favor athletes who are in a more developed maturational stage or those who have more advanced physical development compared to their younger counterparts born in the same year. This advantage occurs mainly in sport whose physical characteristics are determinant for obtaining success, such as volleyball, which leads to the premature exclusion or dropout of potential talents from sport. This study aims at assessing the RAE presence in Brazilian men's and women's elite volleyball by analysing the number of athletes who were born in each trimester of the year and had been ranked to the main national Super Leagues. The results showed no effect related to the RAE in Brazilian women's elite volleyball, whereas there was a higher representation of male athletes born in the first trimester compared to the ones born on the 3rd and 4th trimesters. These results point to a need for better understanding the causes and consequences of RAE in Brazilian men's volleyball in order to avoid premature exclusion or dropout of potential talents, thus, enabling an even greater development of this sport in the country.

RESUMO O efeito da idade relativa (EIR) refere-se à vantagem de atletas nascidos nos primeiros meses do período de seleção em relação a seus pares nascidos em meses posteriores no processo de seleção esportivo, que tende a favorecer atletas que encontram-se em estágio maturacional ou de desenvolvimento físico mais avançados que o de seus colegas mais jovens nascidos no mesmo ano. Esse favorecimento ocorre principalmente em esportes cuja característica física é determinante para se obter sucesso, como o voleibol, acarretando na exclusão ou abandono prematuro da modalidade por parte de talentos em potencial. O objetivo do estudo foi avaliar a presença do EIR no voleibol brasileiro de elite feminino e masculino, pela análise da distribuição do número de atletas rankeados para as Superligas masculina e feminina nascidos em cada trimestres do ano. Os resultados indicaram não haver EIR no voleibol feminino brasileiro de elite, enquanto no masculino há uma maior representação de atletas nascidos no primeiro trimestre em comparação àqueles nascidos nos 3º e 4º trimestres. Esses resultados apontam para a necessidade de se entender melhor as causas e consequências do EIR no voleibol masculino brasileiro, afim de evitar a exclusão ou abandono precoce do esporte de possíveis talentos, permitindo um maior desenvolvimento da modalidade no país.

Relative age effect and dropout causes in a multisport club setting. Is there a special reason to give up?

The aim of the present study was 1) compare the drop-out rates between athletes born in different trimesters of the competitive year from different sports and 2) identify the causes pointed by the dropped-out athletes born in different selection year trimesters to disengage from the competitive sports environment. Methods: Data from 966 athletes who left the competitive sports context were analyzed under the Relative Age Effect (RAE) theoretical framework during 3 consecutive seasons. The drop-out rate and the reason to quit the competitive environment were analyzed by a routine club questionnaire. Results: An expected reverse RAE on drop-out rates was identified, in which the early born athletes were overrepresented (p<0.001). Regarding the reasons to disengage from competitive sports environment, no reason emerged as the main cause to dropout between athletes born in different selection year trimester. Conclusion: It was concluded that despite the common assumption that personal psychological issues related to RAE in late born athletes are important factors influencing sports disengagement, the relationship between drop-out and RAE is more complex and multifactorial.(AU)

Síndrome de Burnout em Árbitros de Futebol / Síndrome de agotamiento en árbitros de fútbol / Burnout síndrome in soccer referees

O contexto de atuação do árbitro de futebol está associado a diversas condições que podem gerar estresse laboral, como necessidade de manter controle emocional frente ao comportamento emocional de treinadores e atletas e pouco reconhecimento profissional. Esse quadro de sobrecarga pode torná-lo propenso à síndrome de exaustão profissional conhecida como burnout. O presente estudo tem como objetivo avaliar e comparar a percepção da síndrome em árbitros de futebol em relação às variáveis grau de escolaridade, nível de arbitragem, função na arbitragem, federação de atuação e tempo de arbitragem. Participaram do estudo 72 árbitros de futebol de dois Estados do Brasil. Foram utilizados o "Inventário de Burnout para Árbitros", composto por nove itens que contemplam as três dimensões da síndrome, e um questionário sociodemográfico. Para a análise de dados foram utilizados a estatística descritiva e o teste U de Mann Whitney (p ≤ 0.05). A única variável que apresentou efeito na percepção da síndrome de burnout foi o Estado de filiação. Árbitros filiados à Federação do Amapá apresentaram maior percepção de duas dimensões de burnout em relação a árbitros filiados à Federação do Pará: reduzido senso de realização esportiva e desvalorização esportiva. O estudo aponta a necessidade de se levar em consideração os fatores contextuais e organizacionais na percepção de burnout em árbitros de futebol (AU)

El contexto de actuación del árbitro de fútbol se asocia con una serie de condiciones que pueden causar estrés en el trabajo, tales como la necesidad de mantener el control emocional frente al comportamiento emocional de entrenadores y atletas y el poco reconocimiento profesional. Esta condición de sobrecarga puede hacer que sea propenso al síndrome de agotamiento profesional. Este estudio tiene como objetivo comparar la percepción del síndrome en el arbitraje con respecto a las variables grado de escolaridad, nivel de arbitraje, función en el arbitraje, federación de actuación y tiempo de arbitraje. El estudio incluyó a 72 árbitros de fútbol de dos estados de Brasil. Se utilizaron el "Inventario Burnout de los árbitros", compuesto por nueve elementos que componen las tres dimensiones del síndrome, y un cuestionario sociodemográfico. Para el análisis de datos se utilizaron la estadística descriptiva y la prueba de Mann-Whitney (p ≤ 0.05). La única variable que tuvo efecto sobre la percepción del síndrome de agotamiento fue el Estado de afiliación. Árbitros afiliados a la Federación de Amapá mostraron una mayor percepción de dos dimensiones del agotamiento en relación con los árbitros afiliados a la Federación de Pará: reducción en el sentido del logro deportivo y la devaluación del deporte. El estudio señala la importancia de los factores contextuales y organizativos en la percepción de agotamiento en árbitros de fútbol (AU)

The action context of the football referee is associated to several conditions that can induce work stress, such as the need to maintain emotional control in the face of the lack of emotional control of coaches and athletes and little professional recognition. This overload scenario can expose these professionals to burnout syndrome. The purpose of this study was to compare the perception of the syndrome related to the variables: educational level, performance level, function in the field, State federation and arbitration time. Seventy-two football referees from two Brazilian states participated in the study. The "Burnout Inventory for Referees" was used. It is composed of nine items that contemplate the three dimensions of the syndrome, and a sociodemographic questionnaire was also employed. Descriptive statistics and the Mann Whitney U test were used for the data analysis (p ≤ 0.05). The only variable that showed an effect on the perception of burnout syndrome was the State of affiliation. Referees affiliated to the federation of Amapá presented greater perception of two dimensions of burnout in relation to referees affiliated to the Federation of Pará: reduced sense of sportsaccomplishment and sports depreciation. The study points out the relevance of contextual and organizational factors in the perception of burnout in soccer referees (AU)

Relative age effect on the reaction time of soccer players under 13 years old / A influência do efeito da idade relativa no tempo de reação em jogadores de futebol sub 13 / La influencia del efecto de la edad relativa en el tiempo de reacción de jugadores de fútbol sub 13

The relative age effect, which is the advantage obtained by an athlete born closer to the beginning of the selection year, has been shown to be an important variable in the development of soccer players. This study aimed to evaluate the influence of the season of birth on the choice reaction time (CRT) of elite soccer athletes in the under 13 years of age category. Seventy-six athletes participated who were 13.36 ± 0.45 years old. The volunteers were tested with a CRT test, and the results were divided according to the semester of birth (S1 or S2). We conducted a t-test in order to compare the results between groups and a Pearson correlation analysis to verify the associations between variables. The results indicated no differences in reaction time (r= .033 and p = .772) or movement time (r = .0073 and p = .530). It was concluded that for this population, the season of birth does not influence the performance of the capabilities tested.

O efeito da idade relativa, que consiste na vantagem obtida pelo atleta nascido mais próximo ao início do ano de seleção, tem se mostrado uma variável importante para o processo de seleção de esportistas. Este estudo objetivou avaliar a influência da época de nascimento no tempo de reação de escolha de futebolistas presentes nas categorias de base (sub 13) de clubes profissionais futebol. Participaram 76 atletas com idade de 13,36 ± 0,45 anos. Os voluntários foram submetidos ao teste do TRE, e os resultados categorizados conforme o semestre de nascimento (S1 ou S2). Foi empregado o teste t para a comparação entre grupos, e análise de Correlação de Pearson para verificar a existência de associações entre as variáveis. Os resultados não indicaram diferenças entre os grupos no tempo de reação (r = 0,033 e p = 0,772) e no tempo de movimento (r = 0,0073 e p = 0,530). Concluiu-se que para essa população, a época de nascimento não influencia no desempenho dessa capacidade.

El efecto de la edad relativa, que consiste en el beneficio obtenido por el atleta nacido más cercano al inicio del año de selección ha sido una variable importante para el proceso de selección de los atletas. Este estudio tuvo como objetivo evaluarla influencia de la época de nacimiento en el tiempo de reacción de los jugadores presentes en los jóvenes (menores de 13) de los clubes de fútbol profesional. Participaron 76 atletas de edad 13,36 ± 0,45 años. Los voluntarios fueron sometidos a la prueba de la TRE, y se clasificaron de acuerdo con el semestre de nacimiento (S1 o S2). Se utilizó el "teste t" para la comparación entre los grupos, y el análisis de correlación de Pearson para verificar la existencia de asociaciones entre variables. Los resultados indicaron que no hubo diferencias entre los grupos en el tiempo de reacción (r = 0,033 e p = 0,772) y el Tiempo de Movimiento (r = 0,0073 e p = 0,530). Se concluyó que para esta población, la fecha de nacimiento no influye en el rendimiento de esta capacidad.

Relative age effect in Olympic Taekwondo athletes.

Relative age effects refer to the effects of age differences among individuals who have been grouped together for a performance activity. This study aimed to investigate the relative age effect on Olympic Taekwondo athletes, in several Olympic Games, and in both sexes. The study sample consisted of 291 athletes who had competed in Atlanta, Sydney, and Beijing Olympic Games. The relative age effect was examined for the general distribution of athletes by quartile, for each of the individuals, and for male and female athletes. There were no discernable effects of relative age on Olympic Taekwondo athletes.

Efeito da idade relativa no futsal de base de Minas Gerais / Relative age effect in futsal in Minas Gerais / El efecto de la edad relative en el fútbol sala de las categorias de base de Minas Gerais

O Efeito da Idade Relativa, representado pela vantagem obtida pelo atleta nascido mais próximo ao início do ano de seleção, mostra-se uma variável significativa para a identificação de talentos em diversas modalidades. Objetivou-se avaliar o quartil de nascimento de atletas das categorias de base do futsal em Minas Gerais. Foram analisados 510 atletas inscritos em competições federadas em 2009. Para análise empregou-se o teste de qui-quadrado. Verificou-se diferenças significativas na distribuição dos quartis de nascimento em quatro das cinco categorias avaliadas, com predominâncias do primeiro e segundo quartis. Concluiu-se que o Efeito da Idade Relativa é um fator que pode influenciar a seleção de atletas nas categorias de base do futsal.

The effect of relative age, understood as the advantage obtained by athletes born in the beginning of the year of selection, is a significant variable for the development of talents in several modalities. Therefore, the objective is to assess the quartile of birth of athletes of the minor league categories of futsal in Minas Gerais. The sample was composed by 510 athletes enrolled in federated competitions in 2009. The chi-square test was used in this analysis. There were significant differences in the distribution of the quartiles of birth in four of the five categories assessed, with a predominance of the first and second quartiles. In conclusion, the effect of relative age is a factor which might influence the choice of futsal players in the base categories.

El efecto de la edad relativa, entendido como la ventaja obtenida por el atleta nacido em las primeras fechas del año de selección, se muestra una variable significativa para el desarrollo de talentos en distintas modalidades. Por esta se evaluó el cuartil de nacimiento de atletas de las categorias base del fútbol sala em Minas Gerais. La muestra estaba compuesta por 510 atletas inscritos en competiciones federadas en 2009. Para este análisis fue empleado el test de chi-cuadrado. Fueron encontradas diferencias significativas en la distribucíon de los cuartiles de nacimiento em cuatro de las cinco categorias evaluadas, con predomínio del primer y segundo. Se concluyó que el efecto de la edad relativa es un factor que puede influenciar em la selección de jugadores de fútbol sala em las categorias de base.