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Search Results: 1 - 10 of 147776 matches for " Fábio Yuzo Nakamura "
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Autonomic correlates of Yo-Yo performance in soccer referees
Boullosa, Daniel A.;Nakamura, Fábio Yuzo;Perandini, Luiz Augusto;Leicht, Anthony Scott;
Motriz: Revista de Educa??o Física , 2012, DOI: 10.1590/S1980-65742012000200009
Abstract: we tested the hypothesis that: basal cardiac autonomic modulation (i.e. heart rate variability, hrv) was associated with the parasympathetic withdrawal during, and overall yo-yo ir1 performance; and therefore hrv could be used as a simple tool for specific fitness assessment. nine sub-elite soccer referees performed the yo-yo ir1 until exhaustion with simultaneous recording of heart rate with the autonomic response during exercise calculated as the area under the curve (auc). in the same week but with at least 48 hrs between days, a night-time hr recording was obtained from participants for determination of basal hrv. correlation analysis demonstrated strong (r>0.83) relationships among yo-yo ir1 performance, auc and basal hrv. these results indicate that both nocturnal hrv and auc can be utilised as simple and valid monitoring tools of soccer referees' fitness.
Carga interna, tolerancia ao estresse e infec??es do trato respiratório superior em atletas de basquetebol
Freitas, Camila Gobo;Aoki, Marcelo Saldanha;Arruda, Ademir Felipe Schultz;Nakamura, Fábio Yuzo;Moreira, Alexandre;
Revista Brasileira de Cineantropometria & Desempenho Humano , 2013, DOI: 10.5007/1980-0037.2013v15n1p49
Abstract: the present study aimed to investigate the effect of external training load manipulation on internal training load (itl), stress tolerance (st) and upper respiratory tract infection (urti) severity in basketball players during a 19-week macrocycle. the macrocycle was divided into three distinct phases: preparatory phase (p1) and two competitive phases (p2 and p3). the daily analysis of life demands for athletes questionnaire (dalda), for assessment of sources and symptoms of stress, and the wisconsin upper respiratory symptom survey (wurss-21), for evaluation of urti severity, were used on a weekly basis. the itl was assessed by rating of perceived exertion (session rpe). there was a decrease in itl at p3 when compared to p1 and p2 (p < 0.05). a decrease in "better than normal" responses in dalda for both sources and symptoms of stress was observed at p2 and p3 when compared to p1 (p < 0.05). there was also a significant increase in urti severity. in addition, significant relationships between st and urti were shown at p3, suggesting that stress tolerance may modulate urti severity. in summary, etl manipulation induced changes in itl. however, unlike the initial hypothesis, a decrease in itl during the competitive period was followed by a decrease in stress tolerance and an increase in urti severity. furthermore, the magnitude of stress seems to provoke an increase in urti severity.
Percep??o de esfor?o da sess?o e a tolerancia ao estresse em jovens atletas de voleibol e basquetebol
Moreira, Alexandre;Freitas, Camila Gobo de;Nakamura, Fábio Yuzo;Aoki, Marcelo Saldanha;
Revista Brasileira de Cineantropometria & Desempenho Humano , 2010, DOI: 10.1590/S1980-00372010000500006
Abstract: the present study investigated the effect of training load distribution on the perceived sources and symptoms of stress during 6 weeks of sports training in young athletes. the session rpe method and the dalda questionnaire were used to assess internal training load and stress tolerance. twenty young men athletes participated in this study. repeated measures anova revealed higher training loads in the first and second weeks of training (p<0.05). interestingly, increased symptoms of stress were also observed in the first two weeks of training, with a similar tendency for sources of stress when the group was analyzed as a whole. a significant increase in the "worse than normal" answers in part b of the dalda questionnaire (symptoms of stress) was observed for the subgroup submitted to a higher training load (>400 au) (two-way anova, p<0.05). the present findings support the hypothesis that the internal training load (session rpe) affects stress tolerance. these results emphasize the importance of regular training monitoring in order to reduce the occurrence of deleterious adaptations and to optimize desired adaptive responses.
Estimativa do custo energético e contribui??o das diferentes vias metabólicas na canoagem de velocidade
Nakamura, Fábio Yuzo;Borges, Thiago Oliveira;Sales, Odair Rodrigo;Cyrino, Edilson Serpeloni;Kokubun, Eduardo;
Revista Brasileira de Medicina do Esporte , 2004, DOI: 10.1590/S1517-86922004000200002
Abstract: the performance of the speed kayaking depends on the organism capacity of regenerating atp in large amounts and high rates from different metabolic pathways. thus, the objective of the present study was to combine two bioenergetic models, the first a generic one, called critical power, and the other specific for kayaking, proposed by zamparo et al. (1999), in the attempt of producing estimations of aerobic and anaerobic fitness for this modality, as well as establishing non-invasive estimations of the contribution of aerobic and anaerobic systems for different distances performed. in that purpose, 11 male kayaking athletes (16.0 ± 1.2 years; 174.0 ± 2.4 cm; 65.2 ± 4.4 kg), performed different distances (500, 1,000 and 1,790 m), at the maximal speed as possible in kayaks type k-1 in a calm water lake. the informations obtained were initially converted into work generated quantity (kj) and internal power (w). the estimated individual values were afterwards applied to three predictive equations of critical power (pcrit) and anaerobic work capacity (ctanaer). finally, the values produced were transformed into oxygen equivalence units for the estimation of the aerobic contribution (o2 equivalence for pcrit x time required to perform the distance) and anaerobic contribution (o2 equivalence for ctanaer x time required to perform the distance) at the different distances. the relative anaerobic contribution found for the different distances analyzed (500, 1,000 and 1,790 m) was of 60.6; 78.6 and 89.4%, respectively. the results found corroborate the information previously produced by other investigations, suggesting that the procedures adopted in this study may provide reliable estimations on the participation of the energetic pathways on the kayaking performance.
The psychobiological model: a new explanation to intensity regulation and (in)tolerance in endurance exercise Modelo psicobiológico: uma nova explica o para o controle da intensidade e (in)tolerancia durante exercícios de resistência cardiorrespiratória
Bruno Paula Cara?a Smirmaul,José Luiz Dantas,Fábio Yuzo Nakamura,Gleber Pereira
Revista Brasileira de Educa??o Física e Esporte , 2013,
Abstract: The mechanisms underpinning fatigue and exhaustion, and the specific sources of exercise-endurance intensity regulation and (in)tolerance have been investigated for over a century. Although several scientific theories are currently available, over the past five years a new framework called Psychobiological model has been proposed. This model gives greater attention to perceptual and motivational factors than its antecedents, and their respective influence on the conscious process of decision-making and behavioral regulation. In this review we present experimental evidences and summarize the key points of the Psychobiological model to explain intensity regulation and (in)tolerance in endurance exercise. Still, we discuss how the Psychobiological model explains training-induced adaptations related to improvements in performance, experimental manipulations, its predictions, and propose future directions for this investigative area. The Psychobiological model may give a new perspective to the results already published in the literature, helping scientists to better guide their research problems, as well as to analyze and interpret new findings more accurately. Os mecanismos que explicam fadiga e exaust o, controle da intensidade e (in)tolerancia ao exercício de resistência cardiorrespiratória têm sido estudados há mais de um século. Apesar de diversas teorias científicas atualmente disponíveis, nos últimos cinco anos um novo modelo chamado de Psicobiológico tem sido proposto. Este modelo dá maior importancia aos fatores perceptuais e motivacionais em rela o aos seus antecessores, bem como a respectiva influência destes fatores no processo consciente de tomada de decis o e controle comportamental. Nesta revis o, nós apresentamos evidências experimentais e sintetizamos os pontos chaves do modelo Psicobiológico que explicam o controle da intensidade e (in)tolerancia ao exercício de resistência cardiorrespiratória. Adicionalmente, nós discutimos como o modelo explica as adapta es ao treinamento relacionadas à melhora no desempenho, as manipula es experimentais e suas predi es. Ao final, propomos futuras dire es para esta área investigativa. O modelo Psicobiológico pode proporcionar uma nova perspectiva aos resultados anteriormente publicados na literatura, ajudando os cientistas a entenderem melhor seus problemas de pesquisa, assim como analisar e interpretar novas evidências mais precisamente.
Session RPE and stress tolerance in young volleyball and basketball players
Alexandre Moreira,Camila Gobo de Freitas,Fábio Yuzo Nakamura,Marcelo Saldanha Aoki
Revista Brasileira de Cineantropometria e Desempenho Humano , 2010,
Abstract: The present study investigated the effect of training load distribution on the perceivedsources and symptoms of stress during 6 weeks of sports training in young athletes. The sessionRPE method and the DALDA questionnaire were used to assess internal training load and stresstolerance. Twenty young men athletes participated in this study. Repeated measures ANOVArevealed higher training loads in the first and second weeks of training (p<0.05). Interestingly,increased symptoms of stress were also observed in the first two weeks of training, with a similartendency for sources of stress when the group was analyzed as a whole. A significant increasein the “worse than normal” answers in part B of the DALDA questionnaire (symptoms ofstress) was observed for the subgroup submitted to a higher training load (>400 AU) (two-wayANOVA, p<0.05). The present findings support the hypothesis that the internal training load(session RPE) affects stress tolerance. These results emphasize the importance of regular trainingmonitoring in order to reduce the occurrence of deleterious adaptations and to optimize desiredadaptive responses.
Correlation between critical force and critical velocity and their respective stroke rates
Luiz Augusto Buoro Perandini,Nilo Massaru Okuno,Eduardo Kokubun,Fábio Yuzo Nakamura
Revista Brasileira de Cineantropometria e Desempenho Humano , 2006,
Abstract: The critical power model has been utilized to estimate the anaerobic and aerobic capacities in swimming. There are studies which evidence the applicability of swimming velocity, force during tethered swimming and stroke rate data to the critical power model. However, the relationship among these estimates derived from freestyle and tethered swimming needs to be established. Therefore, the aim of this study was to evaluate the relationship between critical force (FCRIT) obtained from tethered swimming and critical velocity (VCRIT) during freestyle swimming (VCRIT), and their respective critical stroke rates (FBrCRIT). Eleven swimmers of both sexes (16.6 ± 1.3 years, 60 ± 10 kg, 172 ± 8 cm) underwent maximal tests to exhaustion in the tethered system and to as fast as possible trials during 200 and 400 m freestyle swimming. There were estimates of: 1) FCRIT and CIAnaer fi tting the three known equations derived from the critical power model (hyperbolic forcetime F-t, linear force-1/time F-1/t, linear impulse-time I-t); 2) VCRIT and CNAnaer during the freestyle tests using the linear distance-time relationship (d-t) and; 3) FBrCRIT and CBrAnaer during both kinds of tests (tethered and freestyle). The tethered performance data presented a good fi tting to the critical power model: FCRIT (R2 of 0.98, 0.97 and 0.99) and FBrCRIT-TETHERED (R2 of 0.96, 0.90 and 0.99). There was a high correlation between VCRIT and FCRIT (r= 0.89-0.91). Nevertheless, there was no signifi cant correlation among the estimates of FBrCRIT-TETHERED and FBrCRIT-FREESTYLE, neither among the anaerobic variables. These results indicate that FCRIT can be considered a reliable aerobic capacity index. However, the FBrCRIT-TETHERED did not approach this capacity, despite the good fi tting to the critical power model. RESUMO O modelo da potência crítica tem sido utilizado para estimar a capacidade anaeróbia e aeróbia na nata o. Há estudos demonstrando que a velocidade de nado livre, for a no nado atado e freqüência de bra adas aderem ao modelo da potência crítica. Entretanto, a rela o entre essas estimativas no nado livre e atado necessita ser elucidada. Assim, o objetivo do estudo foi avaliar a rela o entre a for a crítica (FCRIT) no nado atado e a velocidade crítica (VCRIT) em nado livre e as respectivas freqüências críticas de bra ada (FBrCRIT). Onze nadadores de ambos os sexos (16,6 ± 1,3 anos, 60 ± 10 kg, 172 ± 8 cm) foram submetidos à nata o atada até a exaust o e esfor os máximos livres em 200 e 400 m. Foram estimados: 1) FCRIT e CIAnaer através três equa es do modelo de potência c
Behavior of the muscle strength and arm muscle area during 24 weeks of weight training
Alexandre Hideki Okano,Edilson Serpeloni Cyrino,Fábio Yuzo Nakamura,Débora Alves Guariglia
Revista Brasileira de Cineantropometria e Desempenho Humano , 2008,
Abstract: The purpose of this study was to analyze the behavior of muscle strength and arm muscle area (AMA) over24 weeks of weight training (WT) as well as to establish possible associations between these variables. The sample wascomposed of 18 men aged between 18 and 30 years. Measurements of relaxed arm circumference and triceps skinfoldmeasurement were used for the calculation. Muscle strength was assessed using the one-repetition maximum test (1-RM)on the arm curl exercise. The WT protocol lasted 24 weeks, divided into 3 stages (F1, F2, and F3) of 8 weeks each. It isimportant to emphasize that every measurement was made before, during and after the end of the WT period. Analysis ofvariance (ANOVA) for repeated measures followed by the Tukey post hoc (P < 0.05) was used to the compare the indicatorsof muscle strength and muscle hypertrophy. Pearson’s correlation coefficient was used to verify possible association betweenmuscle strength and AMA. Muscle strength and AMA increased continuously throughout the whole period except for theinitial period (F1). Therefore, it is concluded that the initial phase of training, neuromuscular adaptation, seems to havebeen the turning point for increase in muscle strength. After that, the hypertrophy process appears to gradually become theessential factor for increase in muscle strength.
Training load, stress tolerance and upper respiratory tract infection in basketball players. http://dx.doi.org/10.5007/1980-0037.2013v15n1p49
Camila Gobo Freitas,Marcelo Saldanha Aoki,Ademir Felipe Schultz Arruda,Fábio Yuzo Nakamura
Revista Brasileira de Cineantropometria e Desempenho Humano , 2013,
Abstract: The present study aimed to investigate the effect of external training load manipulation on internal training load (ITL), stress tolerance (ST) and upper respiratory tract infection (URTI) severity in basketball players during a 19-week macrocycle. The macrocycle was divided into three distinct phases: preparatory phase (P1) and two competitive phases (P2 and P3). The Daily Analysis of Life Demands for Athletes questionnaire (DALDA), for assessment of sources and symptoms of stress, and the Wisconsin Upper Respiratory Symptom Survey (WURSS-21), for evaluation of URTI severity, were used on a weekly basis. The ITL was assessed by Rating of Perceived Exertion (session RPE). There was a decrease in ITL at P3 when compared to P1 and P2 (p < 0.05). A decrease in “better than normal” responses in DALDA for both sources and symptoms of stress was observed at P2 and P3 when compared to P1 (p < 0.05). There was also a significant increase in URTI severity. In addition, significant relationships between ST and URTI were shown at P3, suggesting that stress tolerance may modulate URTI severity. In summary, ETL manipulation induced changes in ITL. However, unlike the initial hypothesis, a decrease in ITL during the competitive period was followed by a decrease in stress tolerance and an increase in URTI severity. Furthermore, the magnitude of stress seems to provoke an increase in URTI severity.
Effects of previous severe exercise on two and three parameter critical power modeling
Fábio Yuzo Nakamura,Nilo Massaru Okuno,Camila Ferreira Infante Rosa,Edilson Serpeloni Cyrino
Revista Brasileira de Cineantropometria e Desempenho Humano , 2007,
Abstract: The purpose of this study was to apply the two and three-parameter critical power model equations after depletion of a fi xed amount of anaerobic work capacity (AWC), followed by a short rest period. Sixteen subjects underwent: (1) two practice trials for ergometer familiarization to severe exercise; (2) 4-5 exercise bouts on different days for the estimation of critical power (CP) and AWC using the two and three parameter models; (3) the same procedures as described in stage 2 were repeated after 30 s recovery from 180 s of exercise completed at an intensity that would have elicited exhaustion in around 300 s. The CP2parameter (130-174 W versus 131-170 W) and CP3parameter (108 versus 100 W) estimated after prior severe exercise followed by a short rest period remained stable compared to the fatigue-free tests. The AWC2parameter was reduced in response to prior severe exercise. The AWC3parameter was not significantly reduced. The correlations between CP2parameter derived from the same equation with and without prior AWC2parameter reduction were strong (r = 0.97-0.99, P <0.001). The correlation was merely moderate (r = 0.62, P = 0.01) when CP3parameter was analyzed. It can be concluded that the two-parameter critical power model provides a coherent mathematical description of the reduced mechanical output induced by a prior fatiguing task, since AWC2parameter was affected while CP2parameter estimates remained constant. ABSTRACT O propósito do presente estudo foi aplicar as equa es do modelo de potência crítica de dois e três parametros após a deple o de uma quantia fi xa de capacidade de trabalho anaeróbio (AWC), seguido de um período curto de repouso. Dezesseis sujeitos realizaram: (1) duas familiariza es ao exercício severo no cicloerg metro; (2) 4-5 exercícios máximos em dias diferentes para a estimativa da CP e AWC por meio dos modelos de dois e três parametros; (3) os mesmos procedimentos descritos no #2 foram realizados após 30 s de repouso e de um exercício de 180 s a uma intensidade em que a exaust o provavelmente ocorreria em ~300 s. A CP2parameter (130-174 W versus 131-170 W) e CP3parameter (108 versus 100 W) estimadas após o exercício prévio severo e seguido por um curto período de repouso permaneceu estável quando comparado às estimativas sem o exercício prévio. A AWC2parameter foi diminuída em resposta ao exercício prévio severo. A AWC3parameter n o foi significativamente reduzida. As correla es entre CP2parameter derivados da mesma equa o com e sem a redu o prévia da AWC2parameter foram fortes (r = 0,97-0,99; P < 0,001). Para a CP3par
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