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O propósito deste estudo foi analisar a distribuição do mês de nascimento e a influência do efeito relativo da idade (ERI) sobre as medidas antropométricas de jogadores de futebol de elite nacional sub-15. Para tanto, a amostra foi composta por 400 atletas (15,4 ± 0,4 anos; 171.0 ± 10,6 cm e 63,0 ± 8,8 kg) participantes da 11a edição da Copa Brasil de Futebol Sub-15, e que tiveram suas informações de datas de nascimento e medidas de estatura e massa corporal, obtidas a partir de dados disponíveis no site da organização do evento. Os atletas foram separados de acordo com a categorização de idade cronológica em quadrimestres: 1˚ quadrimestre (1˚ QDT) jovens nascidos entre janeiro e abril; 2˚ quadrimestre (2˚ QDT) os nascidos entre maio e agosto, e o terceiro quadrimestre (3˚ QDT) os nascidos entre setembro e dezembro. Os resultados demonstraram diferença estatisticamente significativas entre as frequências de datas de nascimento dos jogadores nos quadrimestres. Da mesma forma, as variáveis antropométricas estatura e massa corporal, apresentaram diferenças significativas entre os quadrimestres. Pode-se concluir que o ERI exerce influência na seleção de jovens jogadores brasileiros de elite por estar associado à diferenças nas características antropométricas.

O esporte cada vez mais diferencia vencedores e perdedores por mínimos detalhes. No basquetebol um fator diferenciador é o lance livre. Sessões de imagética motora (IMA) vêm sendo estudada como um ergogênico sobre o desempenho de lance livre, porém, pouco se estuda o seu efeito agudo, principalmente, em atletas. O objetivo desse estudo foi verificar o efeito de uma sessão prévia de treinamento mental sobre o desempenho no lance livre e na percepção de autoeficácia de jovens atletas. Participaram do estudo 11 atletas juvenis da Federação Paulista de Basquete. Na condição IMA, foram submetidos a 1 minuto de vídeo + 3 minutos de imagética, seguidos de 10 lances livres, e no controle, 4 minutos de repouso seguidos de 10 lances livres. O questionário de autoeficácia foi preenchido antes e após a intervenção. Para análise estatística, foram utilizados os testes U de Mann-Withney, Wilcoxon e o Smallest Wothwhille Change (SWC). Não foi encontrada diferença entre a mediana dos grupos, porém, o SWC apontou uma possibilidade de 84% de efeito benéfico do treinamento mental sobre o desempenho para até 2 lances livres. Concluiu-se que a imagética motora prévia tem 84% de chance de causar um efeito benéfico sobre o desempenho de lance livre em até 2 arremessos.

The purpose of this study was to compare the prefrontal cortex (PFC) blood flow variation and time on in males and females while performing a motor task and imagery perspectives. Eighteen right handed subjects (11 males and 7 females) were volunteers to this study. All subjects went through three randomly conditions, a motor task condition (MT) in which they had to do a simple finger tap. The other conditions included practicing imagery in first and third views. During all the conditions, the fNIRS device was attached to the subject forehead to obtain the blood flow; the total time in each task which was measured with a chronometer. No difference had been found in any condition for both sexes in the PFC and time, nor for all subjects integrated in the PFC. Therefore, we conclu-de that both imageries can be used to mentally train a motor task, and probably both sexes can be benefited.

The objective of this study was to evaluate the effect of a carbohydrate mouth rinse on the repeated sprint ability (RSA) of young soccer players. Nine youth soccer players (15.0 ± 1.5 years; 60.7 ± 4.84 kg; 1.72 ± 0.05 m; 20.5 ± 1.25 kg/m2) were selected. The athletes were submitted to an RSA test consisting of six sprints of 40 m (going/return = 20 m + 20 m), separated by 20 s of passive recovery, under three experimental conditions: carbohydrate mouth rinse (CHO) or placebo (PLA) and control (CON). The mouth rinses containing CHO or PLA were administered 5 min and immediately before the beginning of the test in doses of 100 mL. The best sprint time (RSAbest), mean sprint time (RSAmean), and drop-off in sprint performance (fatigue index) were determined for the different treatments. One-not identify significant differences (p> 0.05) in RSAbest (CHO way ANOVA for repeated measures did = 7.30 ± 0.31 s; PLA = 7.30 ± 0.30 s; CON = 7.26 ±0.16 s), RSA mean (CHO = 7.71 ± 0.30 s; PLA = 7.71 ± 0.25 s; CON = 7.66 ± 0.24s), or fatigue index (CHO = 5.58 ± 2.16%; PLA = 5.77 ± 3.04%; CON = 5.55 ±3.72%). The results suggest that a carbohydrate mouth rinse does not improve the repeated sprint performance of young soccer players.

O objetivo deste trabalho foi analisar osefeitos do enxágue bucal com carboidrato sobre o desempenho, durante sprints repetidos (RSA), de jovens jogadores de futebol. Nove atletas de futebol dacategoria infantil (15,0 ± 1,5 anos; 60,7 ± 4,84 kg; 1,72 ± 0,05 m; 20,5 ± 1,25kg/m2) foram submetidos ao teste de RSA. O teste foi composto por seis sprintsde 40 m (ida/volta = 20 m + 20 m), separados por 20 s de recuperação passiva com três condições experimentais: enxágue bucal com carboidrato (CHO) ou placebo (PLA) e controle (CON). O enxágue bucal com CHO ou PLA foi conduzido 5 min antes e imediatamente antes do início dos testes em doses de 100 mL. Otempo do melhor sprint (RSAbest), a média de tempo dos sprints (RSAmean) e o índice de fadiga (IF) foram determinados nas diferentes condições experimentais. ANOVA one-way para medidas repetidas não identificou diferenças significantes (p> 0,05) para RSAbest (CHO = 7,30 ± 0,31 s; PLA = 7,30 ± 0,30 s; CON = 7,26 ±0,16 s), RSAmean (CHO = 7,71 ± 0,30 s; PLA = 7,71 ± 0,25 s; CON = 7,66 ± 0,24s) e IF (CHO = 5,58 ± 2,16%; PLA = 5,77 ± 3,04%; CON = 5,55 ± 3,72%). Os resultados sugerem que o enxágue bucal com CHO não parece capaz de melhorar odesempenho, sobre sprints repetidos, de jovens jogadores de futebol

The present study determined the neuromuscular fatigue threshold (NFT) using four different time-periods of analysis of the electromyographic signal and compared these estimations with critical power (CP). Fifteen healthy young men (73.6 ± 5.1 kg, 177.8 ± 7.0 cm, 23.4 ± 5.2 years) performed 3-4 different severe constant workload trials until exhaustion on a cycle ergometer with simultaneous SEMG signals acquisition. The obtained data permitted NFT estimation with four different periods of analysis as follows: initial 30s (T30), 1min (T1), 2min (T2) and total time (TT), as well as CP. T30 and T1 were significantly higher than TT and CP and, T2 and TT did not differ between each other, and both were significantly higher than CP. In addition, TT was significantly correlated to CP (0.72; P < 0.05) and to T2 (0.58; P < 0.05). We conclude that NFT overestimates CP, independent of the time-period analysis used for its determination.

The present study determined the neuromuscular fatigue threshold (NFT) using four different time-periods of analysis of the electromyographic signal and compared these estimations with critical power (CP). Fifteen healthy young men (73.6 ± 5.1 kg, 177.8 ± 7.0 cm, 23.4 ± 5.2 years) performed 3-4 different severe constant workload trials until exhaustion on a cycle ergometer with simultaneous SEMG signals acquisition. The obtained data permitted NFT estimation with four different periods of analysis as follows: initial 30s (T30), 1min (T1), 2min (T2) and total time (TT), as well as CP. T30 and T1 were significantly higher than TT and CP and, T2 and TT did not differ between each other, and both were significantly higher than CP. In addition, TT was significantly correlated to CP (0.72; P < 0.05) and to T2 (0.58; P < 0.05). We conclude that NFT overestimates CP, independent of the time-period analysis used for its determination.

Studies have shown that the mere presence of carbohydrate in the human mouth promotes the activation of some specific brain regions, with a positive i mpact on physical performance. Thus, the strategy of carbohydrate mouth rinse has been recently adopted with success in strenuous exercise (> 70% VO2max) lasting approximately 60 min. In this respect, the objective of this study was to discuss, based on literature data, the efficacy of this strategy to improve physical performance, as well as the possible mechanisms involved. The results produced, although still preliminary, are promising and led us to believe that carbohydrate mouth rinse is an interesting strategy, especially because of its easy application, low cost and good efficacy in improving physical performance during intense and prolonged physical exercise

The aim of this study was to evaluate the effect of caffeine intake on critical power model parameters determined on a cycle ergometer. Eight male subjects participated in this study. A double-blind protocol consisting of the intake of pure caffeine (6 mg/kg) or placebo (maltodextrin) 60 min before testing was used. Subjects were submitted to four constant-load tests on a cycle ergometer. These tests were conducted randomly in the caffeine and placebo groups [checar] at intensities of 80, 90, 100 and 110% maximum power at a rate of 70 rpm until exhaustion to determine the critical power. As a criterion for stopping the test was adopted any rate fall without recovery by more than five seconds. The critical power and anaerobic work capacity were obtained by nonlinear regression and fitting of the curve to a hyperbolic power-time model. The Shapiro-Wilk test and paired Student t-test were used for statistical analysis. No significant differences in critical power were observed between the caffeine and placebo groups (192.9 ± 31.3 vs 197.7 ± 29.4 W, respectively). The anaerobic work capacity was significantly higher in the caffeine group (20.1 ± 5.2 vs 16.3 ± 4.2 W, p< 0.01). A high association (r2) was observed between the caffeine and placebo conditions (0.98 ± 0.02 and 0.99 ± 0.0, respectively). We conclude that caffeine intake did not improve critical power performance but increased anaerobic work capacity by influencing performance at loads of higher intensity and shorter duration.

A maioria dos esportes coletivos (ex.: futebol, basquete, handebol) tem como característica a intermitência, flutuando entre breves períodos de esforços máximos ou próximos ao máximo seguidos de períodos e formas de recuperação. Alguns autores têm proposto diversos testes que tem por finalidade mensurar a capacidade desses atletas em realizar esforços repetidos máximos (RSA), a qual estaria diretamente relacionada aos momentos decisivos durante partida. Dessa forma, o presente estudo teve como objetivo descrever os diferentes protocolos de testes para avaliar a RSA em jogadores de futebol, com base em artigos originais e algumas revisões levantadas na base de dados Medline. Diante dos achados, sugerimos a utilização de quatro protocolos, dois envolvendo sprints lineares (AZIZ et al., 2008; REILLY, 2001) e dois utilizando sprints com mudanças de direção (BANGSBO, 2008; IMPELLIZZERI et al., 2008) para avaliação da RSA em jogadores de futebol, gerando importantes parâmetros de desempenho, que permitem ainda a elaboração de programas de treinamento para a melhora dessa capacidade. Recomendamos ainda, a utilização do tempo médio e/ou total como uma medida geral da capacidade de realizar sprints repetidos e as parciais de tempo de cada sprint para identificar possíveis pontos fortes e fraco de cada atleta.The most of team sports (soccer, basketball, handball) is characterized by intermittency, fluctuating between brief periods of maximum effort or near the maximum followed by periods and forms of recovery. Some authors have proposed several tests to measure the ability of these athletes to perform repeated sprints (repeated sprint ability - RSA), which would be directly related to the decisive moments during match. Then, this study aimed to describe the different test protocols to assess RSA in soccer players, based on original articles and reviews selected in some databases (Medline). Therefore, we suggest four protocols, two involving sprints linear (Aziz et al. 2008; Reilly, 2001) and two involving sprints with changes of direction (Bangsbo, 2008; Impellizzeri et al., 2008) to evaluate the RSA in soccer players, generating important performance parameters, which allow to develop training programs to improve that capacity. We also recommend the use of average and/or total time as a general measure of ability to perform repeated sprints and the partial duration of each sprint to identify strengths and weakness of each athlete.

O objetivo do presente estudo foi investigar os efeitos ergogênicos da ingestão de cafeína, sobre o desempenho motor de atletas de judô feminino. Participaram do estudo 13 atletas do sexo feminino (17,6 ± 1,6 anos, 58,3 ± 11,4 kg, 162 ± 4,1 cm, 22,5 ± 4 kg/m²), vinculadas à Federação Paranaense de Judô, por pelo menos dois anos. O desempenho motor foi avaliado mediante a utilização do Special Judô Fitness Test (SJFT), a partir do qual foi analisado o número de arremessos em cada bloco, número total de arremessos, frequência cardíaca (FC) final e de recuperação e o índice no SJFT. Os sujeitos foram testados em duas condições, após ingestão de cafeína (6 mg.kg-1) ou placebo (dextrose) 60 minutos antes dos testes, em um delineamento duplo-cego, cruzado. O número de arremessos em cada bloco não diferiu entre as condições cafeína (CAF) e placebo (PL) (Bloco A: 4,53 ± 0,51 CAF e 4,46 ± 0,51 PL; Bloco B: 8,3 ± 0,63 CAF e 8,23 ± 0,72 PL; Bloco C: 7,23 ± 0,59 CAF e 7,46 ± 0,77 PL), bem como o número total de arremessos (20,07 ± 1,18 CAF e 20,15 ± 1,67 PL), FC (Final: 190,3 ± 9,63 bpm CAF e 190,69 ± 9,19 bpm PL; Recuperação: 162,07 ± 13,78 bpm CAF e 164,3 ± 9,64 bpm PL) e índice no SJFT (17,59 ± 1,4 CAF e 17,75 ± 1,98 PL). A ingestão de cafeína não melhorou o desempenho durante atividade de alta intensidade e curta duração em lutadores de judô.The objective of this study was to investigate the ergogenic effects of caffeine on motor performance of judo female athletes. Thirteen female athletes (17.6 ± 1.6 years, 58.3 ± 11.4 kg, 162 ± 4.1 cm, 22.5 ± 4 kg/m²), registered in the State Federation of Judo for at least two years, participated in this study. The motor performance was assessed using the Special Judo Fitness Test (SJFT), from which was considered the number of throws in each block, the total number of throws, recovery and final heart rate (HR) and final score in SJFT. The subjects were tested in two different conditions, after ingestion of gelatin capsules of caffeine (6 mg.kg-1) or placebo (dextrose) 60 minutes before testing in a randomized double-blind, crossover study. The number of throws in each block did not differs between the caffeine (CAF) and placebo (PL) conditions (Block A: 4.53 ± 0.51 CAF and 4.46 ± 0.51 PL; Block B: 8.3 ± 0.63 CAF and 8.23 ± 0.72 PL; Block C: 7.23 ± 0.59 CAF and 7.46 ± 0.77 PL), as well as the total number of throws (20.07 ± 1.18 CAF and 20.15 ± 1.67 PL), HR (Final: 190.3 ± 9.63 bpm CAF and 190.69 ± 9.19 bpm PL; Recovery 162.07 ± 13.78 bpm CAF and 164.3 ± 9.64 bpm PL) and final score in SJFT (17.59 ± 1.4 CAF and 17.75 ± 1.98 PL). Ingestion of caffeine did not improve performance during high intensity and short duration exercise in judo fighters

The purpose of this study was to determine the influence of different distance combinations on critical velocity (CV) and anaerobic work capacity (AWC). Nineteen swimmers experienced in this training modality participated in the study. CV was calculated by the angular coefficient of the linear regression line between distance and time obtained for each repetition. Five distances (50, 100, 200, 400 and 800 m) performed at an interval of 24 hours were used for the determination of CV, followed by the following four combinations of distances: CV1 (50, 100 and 200 m), CV2 (100, 200 and 400 m), CV3 (200, 400 and 800 m), and CV4 (50, 100, 200, 400 and 800 m). The Shapiro-Wilk test was used to determine the normality of the data. One-way ANOVA was used for comparisons between CV and the different combinations of shots (p < 0.05). The combination of smaller distances (CV1) resulted in an increase of CV (1.47 ± 0.13) and a decrease of AWC (11.91 ± 2.61). The use of shots of medium and long distance resulted in a lower CV (1.38 ± 0.10, 1.34 ± 0.09 and 1.36 ± 0.09 for CV2, CV3 and CV4, respectively) and higher AWC (19.84 ± 6.74, 27.44 ± 6.91 and 18.43 ± 5.21) when compared to short shots. The results suggest that shot distance influences CV and AWC, overestimating or underestimating the speed corresponding to maximum lactate steady state.

The aim of the present study was to investigate the correlation between anthropometric parameters (weight, height, body fat, BMI) and performance indicators (playing time, points, rebounds, errors, steals) in female national basketball players. The study was conducted during the 2000 and 2004 Olympic Games. Data were analyzedby ANOVA with random effects. Pearson’s simple correlation coefficients were also determined. No difference in anthropometric profile or performance indicators was observed between the two national teams (2000 and 2004). There was a significantcorrelation (r = 0.61, p

http://dx.doi.org/10.5007/1980-0037.2008v10n1p76 The purpose of the present study was to identify the anthropometric and motor performance profi le of futsal (indoor soccer) athletes in the second and third-placed teams in the Parana state championships (Brazil). Anthropometric(body mass, stature and skinfolds thickness) and motor performance (modified abdominal test, shuttle run, race of 30 m and 40 s) measures were obtained from twenty-seven male athletes (24.7 ± 6.4 years; 73.6 ± 7.6 kg; 174.8 ± 6.6 cm). For data analysis, athletes were grouped according to game positions. ANOVA one-way was used for comparisons between different positions, followed by Scheffé’s post hoc test, with p < 0.05. Signifi cant differences were detected in body mass (midfielder < goalkeeper, p < 0.01), stature (midfielder < forward and goalkeeper, p < 0.01) and lean body mass (midfi elder < goalkeeper, p < 0.01). No significant differences in motor performance were detected between the athletes studied. The results of this study show that futsal athletes playing in different positions exhibit similar anthropometric and motor performance, in the majority of variables.

The purpose of the present study was to identify the anthropometric and motor performance profile of futsal (indoor soccer) athletes in the second and third-placed teams in the Parana state championships (Brazil). Anthropometric (body mass, stature and skinfolds thickness) and motor performance (modified abdominal test, shuttle run, race of 30 m and 40 s) measures were obtained from twenty-seven male athletes (24.7 ± 6.4 years; 73.6 ± 7.6 kg; 174.8 ± 6.6 cm). For data analysis, athletes were grouped according to game positions. ANOVA one-way was used for comparisons between different positions, followed by Scheffé’s post hoc test, with p < 0.05. Signifi cant differences were detected in body mass (midfi elder < goalkeeper, p < 0.01), stature (midfielder < forward and goalkeeper, p < 0.01) and lean body mass (midfielder < goalkeeper, p < 0.01). No signifi cant differences in motor performance were detected between the athletes studied. The results of this study show that futsal athletes playing in different positions exhibit similar anthropometric and motor performance, in the majority of variables. ABSTRACT Este estudo objetivou identificar o perfil antropométrico e o desempenho motor de atletas de futsal masculino, pertencentes às equipes finalistas do campeonato paranaense da categoria adulto, chave ouro. Para tanto, coletou-se medidas antropométricas (massa corporal, estatura e espessura de dobras cutâneas) e de desempenho motor (testes abdominal modificado, shuttle run, corrida de 30 m e corrida de 40 s) de vinte e sete atletas (24,7 ± 6,4 anos; 73,6 ± 7,6 kg; 174,8 ± 6,6 cm), do sexo masculino. Para a análise dos dados, agrupou-se os atletas de acordo com a posição de jogo. Anova one-way foi empregada para as comparações entre os jogadores das diferentes posições, seguida pelo teste post hoc de Scheffé, com P < 0,05. Verificou-se diferença signifi cante entre os jogadores de diferentes posições de jogo nas variáveis: massa corporal (alas < goleiros, P < 0,01), estatura (alas < pivôs e goleiros, P < 0,01) e massa corporal magra (alas < goleiros, P < 0,01). Não foram observadas diferenças significantes entre os jogadores das diferentes posições de jogo nas variáveis de desempenho motor. Os resultados encontrados no presente estudo sugerem que atletas de futsal apresentam, na maioria das variáveis analisadas, características antropométricas e de desempenho motor semelhantes entre as posições de jogo.

The objective of this study was to analyze the anthropometric characteristics of young futsal (fi ve-a-side soccer) players and to make comparisons between different competitive categories. To this end, 232 male athletes aged 8 to 18 years, playing in the following categories: under-9 (8-9 years; n = 56), under-11 (10-11 years; n = 62), under-13 (12-13 years; n = 36), under-15 (14-15 years; n = 29), under-17 (16-17 years; n = 35) and under-19 (18 years; n = 14), underwent anthropometric measurement to obtain body mass (MB), height, middle-upper arm circumference and skin fold thicknesses (triceps and subscapular). Based on these measurements, body mass index (BMI), sum of skin folds thickness (ΣSF), relative body fat (%fat) and muscular area of the arm (MAB) were all calculated. Motor performance was analyzed based on the results of the following tests: modifi ed 1-minute abdominal (ABD), horizontal impulse (HI), 9/12 minute walk/run (9/12 min) and medicine ball throw (MB). Categories were compared using one-way ANOVA, followed by Scheffé’s post hoc test when p ABSTRACT O propósito do presente estudo foi analisar as características antropométricas de jovens atletas de futsal e, posteriormente, estabelecer comparações entre diferentes categorias competitivas. Para tanto, 232 atletas do sexo masculino, de 8 a 18 anos, das categorias sub 9 (8-9 anos; n = 56), sub 11 (10-11 anos; n = 62), sub 13 (12-13 anos; n = 36), sub 15 (14-15 anos; n = 29), sub 17 (16-17 anos; n = 35) e sub 19 (18 anos; n = 14) foram submetidos a medidas antropométricas de massa corporal (MC), estatura, perímetro braquial e espessura de dobras cutâneas (tríceps e subescapular). A partir dessas medidas foram determinados o índice de massa corporal (IMC), o somatório de espessura de dobras cutâneas (ΣDC), a gordura corporal relativa (% gordura) e a área muscular do braço (AMB). O desempenho motor foi analisado a partir dos seguintes testes motores: abdominal modifi cado 1 minuto (ABD), impulsão horizontal (IH), corrida/caminhada em 9/12 minutos (9/12 min) e arremesso de bola medicinal (BM). ANOVA one-way, seguida do teste post hoc de Scheffé quando p

The objective of the present study was to analyze the articulate torque (TO) and the electromyographic activity (EMG) of soccer athlete’s long head Biceps Femoris (BF) and Semitendinosus (ST) muscles during isokinetic knee fl exion movements (concentric-CON and eccentric-ECC actions) at differing velocities, carried out in the ventral decubitus position. Fourteen soccer players aged 19 and 20 years old (71.2 ± 6.5 kg, 176.6 ± 6.4 cm) were enrolled from the Associação Atlética Ponte Preta under- 20 team. They followed a protocol specifying 5 repetitions of fl exion (CON and ECC action) of the knee at three velocities (60, 180 and 300º/s) at random. The recovery interval between series adopted was 3 minutes. EMG Activity was recorded using surface electrodes and data were expressed in terms of root mean squares (RMS). Statistical analysis employed analysis of variance (Friedman test) for repeated measures followed by the Wilcoxon test when necessary, with the level of signifi cance set at P ABSTRACT O objetivo do presente estudo foi analisar o torque articular (TO) e a atividade eletromiográfi ca (EMG) dos músculos Bíceps Femoral (BF) cabeça longa e semitendíneo (ST) durante movimentos isocinéticos de fl exão do joelho (ação concêntrica-CON e excêntrica-EXC), em diferentes velocidades de execução, na posição de decúbito ventral em atletas de futebol. Fizeram parte do estudo 14 atletas de futebol da equipe sub-20, da Associação Atlética Ponte Preta, com idade entre 19 e 20 anos (71,24 ± 6,53 kg, 176,59 ± 6,44 cm). Os atletas realizaram uma série de cinco repetições de fl exão (ação CON e EXC) do joelho, em 3 velocidades (60, 180 e 300°/s), defi nidas anteriormente aleatoriamente. O intervalo de recuperação adotado entre as séries foi de 3 minutos. A atividade EMG foi coletada, utilizando-se eletrodos de superfície e os dados foram expressos em root mean square (RMS). Para análise estatística, foi empregada a análise de variância (teste Friedman) de medidas repetidas e, quando necessário, empregou-se o teste de Wilcoxon para a localização das diferenças com nível de significância de P

During a soccer match, countless movements involving muscular force are performed. While some studies have analyzed the force exerted by soccer players, their results have been divergent, particularly when force has been analyzed with respect to fi eld positions. The objective of this study was to compare peak torque, total muscular work, maximum power and isokinetic fatigue index of the knee fl exor and extensor muscles of soccer players in a variety of fi eld positions. Seventy-eight under-twenty soccer players were classifi ed according to the position they play: goalkeepers (n=7), full backs (n=14), wingers (n=16), defensive midfi elders (n=11), center midfi elders (n=14) and forwards (n=16). The concentric isokinetic force of knee fl exor and extensor muscles was evaluated using an isokinetic dynamometer, Cybex® brand Norm™ 6000 model (CSMI, USA). Data was analyzed in terms of non-parametric statistics and results expressed in medians and semi-interquartile range. The Kruskal-Wallis test was applied and when results were signifi cant to pRESUMO Durante uma partida de futebol são realizados inúmeros movimentos que envolvem a força muscular. Embora alguns estudos tenham analisado a força de jogadores de futebol, os resultados encontrados têm sido controversos, principalmente quando analisada a força em função da posição de jogo. O objetivo deste estudo foi comparar o pico de torque, trabalho muscular total, potência máxima e índice de fadiga isocinético dos músculos fl exores e extensores de joelho de jogadores de futebol que atuam em diferentes posições de jogo. Foram incluídos 78 atletas de futebol, pertencentes à categoria Sub-20, foram agrupados de acordo com a posição em campo de jogo: goleiros (n=7), zagueiros (n=14), laterais (n=16), volantes (n=11), meio campo (n=14) e atacantes (n=16). Foi realizada avaliação da força isocinética concêntrica dos músculos fl exores e extensores de joelho em dinamômetro isocinético da marca Cybex®, modelo Norm™ 6000 (CSMI, USA). A análise dos dados foi realizada por meio de estatística não-paramétrica sendo os valores expressos em mediana e semi-amplitude interquartílica. Foi empregado teste de Kruskal-Wallis e teste U de Mann-Whitney quando encontrados valores signifi cantes, com p

The objective of the present study was to investigate the infl uence of two linear models on the determination of critical potential (CP) and anaerobic work capacity (AnWC) of canoeists evaluated on an arm ergometer. Eight male canoeists (17.1 ± 1.1 years; 63.3 ± 6.5 kg; 173.4 ± 4.3 cm) volunteered to take part in the study. Two different linear equations were employed to calculate CP and AnWC: power-1/time and work-time, using three different power levels (Wlim) and their respective times to exhaustion (tlim). The athletes underwent six test sessions on an arm ergometer at 70 rpm until voluntary exhaustion, with and interval of 24 hours between sessions, at two different intensities each day, with a minimum interval of 90 minutes. The statistical analysis employed descriptive statistics, Student’s t test and Pearson’s linear correlation (P < 0.05). The power-1/time equation produced a signifi cantly higher CP than the work-time equation (144.6 ± 17.3 W vs. 141.9 ± 16.5 W, respectively; P < 0.05), whereas AnWC was signifi cantly greater when calculated by work-time than when calculated by power-1/time (12.8 ± 2.9 kJ vs. 13.9 ± 3.2 kJ; respectively, P < 0.05). The coefficient of correlation between power-1/time and work-time for CP and AnWC was r=0.98 and r=0.92, respectively (P < 0.05). Despite this high level of correlation between the models in terms of CP and AnWC, the results suggest that adopting different models appears to interfere in the calculation of CP and AnWC of exercise on an arm ergometer. RESUMO O objetivo do presente estudo foi verifi car a infl uência de dois modelos lineares na determinação da potência crítica (PC) e da capacidade de trabalho anaeróbio (CTAn), em ergômetro de braço, em atletas de canoagem. Para tanto, oito canoístas do sexo masculino (17,1 ± 1,1 anos; 63,3 ± 6,5 kg; 173,4 ± 4,3 cm), participaram voluntariamente desta investigação. A PC e a CTAn foram obtidas por meio de duas equações lineares: potência-1/tempo e trabalho-tempo, utilizando três potências (Wlim) e seus respectivos tempos até a exaustão (tlim). Os atletas foram submetidos a seis sessões de testes em ergômetro de braço a 70 rpm até a exaustão voluntária, com intervalo de 24 horas entre cada sessão, a duas intensidades diferentes a cada dia, com intervalo mínimo de 90 minutos. Para o tratamento estatístico utilizou-se a estatística descritiva, teste t de Student e correlação linear de Pearson (P < 0,05). A PC da equação potência-1/tempo foi significativamente maior que da equação trabalho-tempo (144,6 ± 17,3 W vs 141,9 ± 16,5 W, respectivamente; P < 0,05), enquanto que a CTAn foi signifi cativamente maior no modelo trabalho-tempo em relação ao modelo potência-1/tempo (12,8 ± 2,9 kJ vs 13,9 ± 3,2 kJ; respectivamente, P < 0,05). A correlação obtida para PC e CTAn entre os modelos potência- 1/tempo e trabalho-tempo foram r=0,98 e r=0,92, respectivamente (P < 0,05). Apesar da alta correlação encontrada entre os modelos para os valores de PC e CTAn os resultados sugerem que a adoção de diferentes modelos parece interferir no cálculo da PC e CTAn em exercício realizado no ergômetro de braço.

Abstract Aim: To investigate the effects of low-intensity walk training with and without blood flow restriction (BRF) on resting heart rate variability (HRV) and blood pressure (BP) in middle-aged men. Methods: Twenty-one men were randomly assigned into the walk training group with (BRF-W; n = 11) and without (NOR-W; n = 10) BFR. The resting HRV and blood pressure were assessed pre- and post-6 weeks of the intervention [3 times/week, 5 sets of 3-min walking (6 km.h-1) with 1-min of rest, totalizing 18 sessions of training]. The BFR-W group received the occlusive stimulus before of training sessions though of a standard sphygmomanometer and performed the training sessions with the vascular occlusion (80-100 mmHg) in both the legs. Results: Only BRF-W group improved HRV on time domain indices (SDNN and RMSSD; p < 0.05) after training but it was not found differences on frequency domain indices. In addition, systolic blood pressure (SBP) improved after training (PRE: 128.5 ± 5.9 vs POST: 119.1 ± 8.6 mmHg; Cohen’s d = -1.30; p < 0.01) only in BFR-W group. There was not a significant difference on diastolic blood pressure (DBP) after training, however, effect size was moderate for BFR-W (Cohen’s d = -0.56; p > 0.05). Conclusion: Our results showed that walking training with blood flow restriction can improve health cardiovascular parameters in middle-aged men.