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Search Results: 1 - 10 of 23434 matches for " Eduardo Bodnariuc Fontes "
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Articulate torque and electromyographic activity of biceps femoris and semitendinosus muscles during isokinetic knee flexion movements in soccer athletes
Carlos Eduardo Bassi Rodrigues,Antonio Carlos de Moares,Alexandre Hideki Okano,Eduardo Bodnariuc Fontes
Revista Brasileira de Cineantropometria e Desempenho Humano , 2007,
Abstract: 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 Associa o 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<0.05. The highest TO fi gures were observed at 60o/s velocity in the CON phase. There was no signifi cant variation in TO between different velocities in the ECC contraction. Moreover, the ECC phase had higher TO values, irrespective of velocity or repetitions. Some of the repetitions of the CON phase at 60o/s exhibited signifi cant difference between the BF and ST muscles. However, in general, the RMS values were not signifi cantly modifi ed by variations in velocity or type of contraction in the BF and ST muscles. Finally, the RMS/TO ratio was not linear under the experimental conditions studied, since, although TO values were different at different velocities and between CON and ECC contraction, whereas the RMS values remained steady. ABSTRACT O objetivo do presente estudo foi analisar o torque articular (TO) e a atividade eletromiográfi ca (EMG) dos músculos Bíceps Femoral (BF) cabe a longa e semitendíneo (ST) durante movimentos isocinéticos de fl ex o do joelho (a o concêntrica-CON e excêntrica-EXC), em diferentes velocidades de execu o, na posi o de decúbito ventral em atletas de futebol. Fizeram parte do estudo 14 atletas de futebol da equipe sub-20, da Associa o 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 repeti es de fl ex o (a o CON e EXC) do joelho, em 3 velocidades (60, 180 e 300°/s), defi nidas anteriormente aleatoriamente. O intervalo de recupera o adotado entre as séries foi de 3 minutos. A atividade EMG foi coletada, utilizando-se eletrodos de superfície e os dado
Efeitos da música eletr nica nos sistemas neuromuscular, cardiovascular e parametros psicofisiológicos durante teste incremental exaustivo Electronic music effects on neuromuscular and cardiovascular systems and psychophysiological parameters during exhaustive incremental test
Bruno de Paula Cara?a Smirmaul,José Luiz Dantas,Eduardo Bodnariuc Fontes,Antonio Carlos de Moraes
Motricidade , 2011, DOI: 10.6063/motricidade.7(3).97
Abstract: O objetivo do presente estudo foi analisar o efeito da música sobre respostas fisiológicas e psicofisiológicas, assim como sobre a potência máxima alcan ada durante um teste incremental. Uma amostra de 10 indivíduos saudáveis (20.8 ± 1.4 anos, 77.0 ± 12.0 kg, 179.2 ± 6.3 cm) participou deste estudo. Foram coletadas a atividade eletromiográfica (músculos Reto Femoral RF e Vasto Lateral VL), a frequência cardíaca (FC), a percep o subjetiva de esfor o (PSE), a percep o subjetiva de tempo (PST) e a potência máxima alcan ada (PMax) durante as situa es com música (CM) e sem música (SM). Os indivíduos completaram quatro testes incrementais máximos (TIMax) do tipo rampa em um ciclossimulador com uma carga inicial de 100 W e aumentos de 10 W·min-1. As médias dos valores de PMax entre as situa es SM (260.5 ± 27.7 W) e CM (263.2 ± 17.2 W) n o apresentaram diferen a significativa. A compara o entre as taxas de aumento dos valores expressos em root-mean-square (RMS) e frequência mediana (FM) para os dois músculos (RF e VL) também n o apresentaram diferen a significativa, assim como a FC, PSE e PST. Conclui-se que a música eletr nica durante um teste incremental até a exaust o n o surtiu efeito sobre as variáveis analisadas para o grupo investigado. The aim of this study was to analyze the music effects on physiological and psychophysiological responses, as well as on the maximum power output attained during an incremental test. A sample of 10 healthy individuals (20.8 ± 1.4 years, 77.0 ± 12.0 kg, 179.2 ± 6.3 cm) participated in this study. It was recorded the electromyographic activity (muscles Rectus Femoris RF and Vastus Lateralis VL), heart rate (HR), rating of perceived exertion (RPE), ratings of perceived time (RPT) and the maximum power output attained (PMax) during music (WM) and without music (WTM) conditions. The individuals completed four maximal incremental tests (MIT) ramp-like on a cycle simulator with initial load of 100 W and increments of 10 W·min-1. The mean values of PMax between conditions WTM (260.5 ± 27.7 W) and WM (263.2 ± 17.2 W) were not statistically different. The comparison between the rates of increase of the values expressed in root-mean-square (RMS) and median frequency (MF) for both muscles (RF and VL) also showed no statistical difference, as well as HR, RPE and RPT. It is concluded that the use of the electronic music during an incremental test to exhaustion showed no effect on the analyzed variables for the investigated group.
Can neuromuscular fatigue threshold bedetermined by short and non-exhaustive bouts?. DOI: http://dx.doi.org/10.5007/1980-0037.2012v14n3p254
Eduardo Bodnariuc Fontes,Alexandre Hideki Okano,Bruno de Paula Smirmaul,Leandro Ricardo Altimari
Revista Brasileira de Cineantropometria e Desempenho Humano , 2012,
Abstract: 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.
Effect of caffeine intake on critical power model parameters determined on a cycle ergometer
Marcus Vinicius Machado,Alexandre Rosas Batista,Leandro Ricardo Altimari,Eduardo Bodnariuc Fontes
Revista Brasileira de Cineantropometria e Desempenho Humano , 2010,
Abstract: 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.
Training level does not influence the rating of perceived exertion during an incremental test
Bruno de Paula Cara?a Smirmaul,José Luiz Dantas,Eduardo Bodnariuc Fontes,Alexandre Hideki Okano
Revista Brasileira de Cineantropometria e Desempenho Humano , 2010,
Abstract: Different training levels, combined with experience in performing exhaustive exercise, may produce different sensations of fatigue. The objective of this study was to compare the rating of perceived exertion (RPE) between cyclists and non-cyclists during a maximal incremental test (ITMAX). Twenty-three subjects were recruited and divided into a cyclist group (CG) (n = 12; age: 26.5 ± 4.7 years, body weight: 68.2 ± 11kg, height: 176 ± 8.6 cm) and a non-cyclist group (NCG) (n = 11; 25.2 ± 4.0 years, body weight: 72.9 ± 9 kg, height: 175.1 ± 6.3 cm). All subjects per formed an ITMAX unt i l exhaust ion on a cycl ing simulator, start ing at 0 W and with increment s of 20 W.min-1. RPE was measured at 30-second intervals during ITMAX and the maximal power output (PMAX) of each subject was also recorded. The total time of each test was normalized to the percentage of completed trial (10% to 100%, intervals of 10%), and the corresponding RPE was recorded. PMAX was 368 ± 12.7 W and 256 ± 11.2 W for CG and NCG, respectively (P < 0.01). No significant difference in median RPE was observed between groups at any time point. In conclusion, RPE responses did not differ between CG and NCG during ITMAX, suggesting that training level does not influence RPE.
THE CAFFEINE INGESTION INCREASES TIME TO NEUROMUSCULAR FATIGUE AND PERFORMANCE DURING SUPRAMAXIMAL CYCLING EXERCISE
Leandro Ricardo Altimari,Eduardo Bodnariuc Fontes,Alexandre Hideki Okano,Ricardo Okada Triana
Brazilian Journal of Biomotricity , 2008,
Abstract: ALTIMARI, L. R.; FONTES, E. B.; OKANO, A. H.; TRIANA, R. O.; CHACON-MIKAHIL, M. P. T.; MORAES, A. C. The caffeine ingestion increases time to neuromuscular fatigue and performance during supramaximal cycling exercise. Brazilian Journal of Biomotricity, v. 2, n. 3, p. 195-203, 2008.The purpose of this study was to investigate the effect of the caffeine ingestion (CAF) on the neuromuscular fatigue (NMF) and performance during supramaximal cycling exercise. Nine male cyclists (27.2 ± 3.9 yr; 73.7 ± 12.3 kg and 174.2 ± 6.1 cm), trained, were subjected to two tests of constant load (Tcons) separated by 72 h intervals in intensity of 110% wmax until exhaustion conducted randomly in CAF and PL conditions. CAF (6 mg.kg-1) or PL (maltodextrin) were administred in a double-blind procedure 60 min before the start of Tcons. During the Tcons were obtained the time of exhaustion (TE) and time of onset of neuromuscular fatigue (TONMF) (s) through electromyographic activity (EMG) of the vastus lateralis (VL), vastus medialis (VM) e rectus femoris (RF) muscles. Normality of the data distribution was confirmed using the Shapiro-Wilk test, and this was followed by Student t-tests with level of significance set at P<0.05. The TE was 15% higher on condition CAF compared to PL (132.3 ± 8.4 and 116.7 ± 7.6 s, P<0.05, respectively). Significant difference was found between the TONMF of VL, VM and RF muscles when compared to CAF and PL conditions (P<0.05). According to these results, it can be concluded that the ingestion of 6 mg.kg-1 of caffeine increases time to neuromuscular fatigue and performance during supramaximal in cycling exercise.
EFFECT OF PEDALING RATE ON PERCEIVED EXERTION AND HEART RATE IN MAXIMAL INCREMENTAL TEST
Rafael Ayres Montenegro,Paulo de Tarso Veras Farinatti,Eduardo Bodnariuc Fontes,Jonas Lírio Gurgel
Brazilian Journal of Biomotricity , 2011,
Abstract: MONTENEGRO, R. A.; FARINATTI, P. T. V.; FONTES, E. B.; GURGEL, J. L.; PORTO, F.; LUZ, L. G. O.; ITABORAHY, A. S.; OKANO, A. H. Effect of pedaling rate on perceived exertion and heart rate in maximal incremental test. Brazilian Journal of Biomotricity. v. 5, n. 3, p. 200-209, 2011. It is known that pedaling cadence affects the mechanical efficiency, the levels of blood lactate, heart rate (HR), oxygen consumption. However, information about how pedaling cadence influences the rating of perceived exertion (RPE) is still scarce. Thus, the purpose of this study was to compare the responses of maximum power, HR and RPE achieved during maximal incremental tests (ITmax), 50 and 100 rpm, with 15W/min up to voluntary exhaustion. The sample (n = 7) comprised physically active individuals (20.4 ± 2.2 years, 73.1 ± 8.3 kg and 176.8 ± 4.6 cm). Were performed two ITmax in cycle ergometer, with cadences of 50 and 100 rpm, performed in random order (minimum of 48 hours between tests). The results showed that RPE was higher in tests with cadence of 100 rpm, but at the end of the test, the RPE did not presented differences between the cadences. Likewise, no significant difference was found in maximal HR (50rpm: 183±7,81bpm vs. 100rpm: 185,6±8,1bpm). Already in submaximal intensities, the HR was higher in the test at 100 rpm. Can conclude that the RPE and HR are influenced by the PC, is higher according to the increase in cadence. This demonstrates the applicability of the use of RPE for monitoring the intensity of effort in exercise programs performed in cycle.
O nível de treinamento n?o influencia a percep??o subjetiva de esfor?o durante um teste incremental
Smirmaul, Bruno de Paula Cara?a;Dantas, José Luiz;Fontes, Eduardo Bodnariuc;Okano, Alexandre Hideki;Moraes, Antonio Carlos de;
Revista Brasileira de Cineantropometria & Desempenho Humano , 2010, DOI: 10.5007/1980-0037.2010v12n3p159
Abstract: different training levels, combined with experience in performing exhaustive exercise, may produce different sensations of fatigue. the objective of this study was to compare the rating of perceived exertion (rpe) between cyclists and non-cyclists during a maximal incremental test (itmax). twenty-three subjects were recruited and divided into a cyclist group (cg) (n = 12; age: 26.5 ± 4.7 years, body weight: 68.2 ± 11kg, height: 176 ± 8.6 cm) and a non-cyclist group (ncg) (n = 11; 25.2 ± 4.0 years, body weight: 72.9 ± 9 kg, height: 175.1 ± 6.3 cm). all subjects performed an itmax until exhaustion on a cycling simulator, starting at 0 w and with increments of 20 w.min-1. rpe was measured at 30-second intervals during itmax and the maximal power output (pmax) of each subject was also recorded. the total time of each test was normalized to the percentage of completed trial (10% to 100%, intervals of 10%), and the corresponding rpe was recorded. pmax was 368 ± 12.7 w and 256 ± 11.2 w for cg and ncg, respectively (p < 0.01). no significant difference in median rpe was observed between groups at any time point. in conclusion, rpe responses did not differ between cg and ncg during itmax, suggesting that training level does not influence rpe.
Can neuromuscular fatigue threshold be determined by short and non-exhaustive bouts?
Fontes, Eduardo Bodnariuc;Okano, Alexandre Hideki;Smirmaul, Bruno de Paula;Altimari, Leandro Ricardo;Gon?alves, Ezequiel Moreira;Triana, Ricardo Okada;Moraes, Antonio Carlos;
Revista Brasileira de Cineantropometria & Desempenho Humano , 2012, DOI: 10.5007//1980-0037.2012v14n3p254
Abstract: 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.
Efeito da ingest?o de cafeína sobre os parametros da potência crítica
Machado, Marcus Vinícius;Batista, Alexandre Rosas;Altimari, Leandro Ricardo;Fontes, Eduardo Bodnariuc;Triana, Ricardo Okada;Okano, Alexandre Hideki;Marques, Alessandro Custódio;Andries Júnior, Orival;Moraes, Antonio Carlos de;
Revista Brasileira de Cineantropometria & Desempenho Humano , 2010, DOI: 10.5007/1980-0037.2010v12n1p49
Abstract: 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.
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