Navegando por Palavras-chave "Anaerobic threshold"
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- ItemAcesso aberto (Open Access)Alternative methods for estimating maximum lactate steady state velocity in physically active young adults(Universidade Federal de Santa Catarina, 2014-07-01) Motoyama, Yuri Lopes [UNIFESP]; Pereira, Paulo Eduardo de Assis [UNIFESP]; Esteves, Gilmar de Jesus [UNIFESP]; Duarte, João Marcos Pereira; Carrara, Vitor Carlos Piubelli; Rissato, Gustavo Mello; Azevedo, Paulo Henrique Silva Marques de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Faculdade Anhanguera de BauruThe aim of this study was to compare the velocities found in the protocols used to measure the indirect individual anaerobic threshold (IATind), glucose threshold (GT) and critical velocity (CV) with the gold standard, the maximum lactate steady state (MLSS) protocol. Fourteen physically active young adults (23±3.1 years; 72±10.97 kg; 176±7 cm; 21±5.36% body fat) performed a 3000-m track running test to determine IATind using the prediction equation and an incremental test on a treadmill to determine GT. The CV was identified by linear regression of the distance-time relationship based on 3000-m and 500-m running performance. The MLSS was identified using two to five tests on different days to identify the intensity at which there was no increase in blood lactate concentration greater than 1 mmol/L between the 10th and 30th minute. A significant difference was observed between mean CV and MLSS (P≤0.05) and there was a high correlation between MLSS and IATind (R2=0.82; P≤0.01) and between MLSS and GT (R2=0.72; P≤0.01). The Bland-Altman method showed agreement between MLSS and IATind [mean difference -0.24 (confidence interval -1.72 to 1.24) km/h] and between MLSS and GT [0.21 (-1.26 to 1.29) km/h]. We conclude that the IATind and GT can predict MLSS velocity with good accuracy, thus making the identification of MLSS practical and efficient to prescribe adequate intensities of aerobic exercise.
- ItemAcesso aberto (Open Access)Avaliação do fluxo arterial mesentérico em humanos durante o exercício(Colégio Brasileiro de Cirurgiões, 1998-02-01) Pereira, Adamastor Humberto; Nectoux Filho, Júlio Lewis; Burihan, Emil [UNIFESP]; Ribeiro, Jorge Pinto; Burger, Marcos Braun; Moraes, Sérgio Ricardo Araújo De; UFRGS Hospital de Clínicas de Porto Alegre Faculdade de Medicina; Hospital de Clínicas de Porto Alegre; Universidade Federal de São Paulo (UNIFESP); UFRGS Faculdade de Medicina Departamento de Medicina Interna; UFRGS Faculdade de MedicinaMesenteric artery blood flow was measured by Doppler ultrasound in eight healthy subjects (age 21-26 years, mean=25.8) submitted to incremental exercise. As cardiovascular responses change above the point at which blood lactate starts to accumulate, a protocol was designed to determine the velocity profile and mesenteric artery flow redistribution along incremental exercise. On the first part of the protocol all individuals were submitted to determinations of lactate thresholds by the enzimatic method modified by Ribeiro et al (1986). On the second test mesenteric artery blood flow and sistolic, reverse and diastolic velocities were measured at rest and immediately after 30 Watts, first lactate threshold, second lactate threshold and at peak exercise. In this way exercise intensities were adjusted for each individual independently of training and physical conditions. Total mesenteric artery blood flow was calculated using planimetric measurement of the velocities waves and area determinations. The Friedman test was used to analise de data. There was no significant change of sistolic velocities during incremental exercise. In the other hand there was a marked decrease of diastolic velocities; a linear decrease of initial diastolic velocities and an abrupt decrease of end-diastolic velocities after the first lactate threshold. At peak exercise a redution of 77% in end-diastolic velocities was observed. A linear reduction of mesenteric artery blood flow was observed and there was no correlation with lactate thresholds; at peak exercise a decrease of 34% was detected. Resting mesenteric blood flow was 1.034± 112 (SE), at 30 Watts 1.002± 124 (SE), at the first lactate threshold 869± 122 (SE), at the second lactate threshold 866± 127 (SE) and at peak exercise 689± 104 (SE).
- ItemSomente MetadadadosChanges in the Salivary Biomarkers Induced by an Effort Test(Georg Thieme Verlag Kg, 2010-06-01) Oliveira, Vanessa Neves de; Bessa, Artur; Silva, Romeu Paulo Martins; Santana, Marcos Gonçalves de [UNIFESP]; Mello, Marco Tulio de [UNIFESP]; Espindola, Foued Salmen; Universidade Federal de Uberlândia (UFU); Universidade Federal de São Paulo (UNIFESP)Physical exercise induces biochemical changes in the body that modify analytes in blood and saliva among other body fluids. This study analyzed the effect of an incremental effort test on the salivary protein profile to determine whether any specific protein is altered in response to such stress. We also measured thresholds of salivary alpha amylase, total salivary protein and blood lactate and searched for correlations among them. Twelve male cyclists underwent a progressive test in which blood and saliva samples were collected simultaneously at each stage. the salivary total protein profile revealed that physical exercise primarily affects the polypeptide corresponding to salivary alpha-amylase, the concentration of which increased markedly during the test. We observed thresholds of salivary alpha-amylase (sAAT), total salivary protein (PAT) and blood lactate (BLT) in 58%, 83% and 100% of our sample, respectively. Pearson's correlation indicates a strong and significant association between sAAT and BLT (r = 0.84, p < 0.05), sAAT and PAT (r = 0.83, p < 0.05) and BLT and PAT (r = 0.90, p < 0.05). the increased expression of the salivary alpha-amylase (sAA) polypeptide suggests that sAA is the main protein responsible for the increase in total protein concentration of whole saliva. Therefore, monitoring total protein concentration is an efficient tool and an alternative noninvasive biochemical method for determining exercise intensity.
- ItemAcesso aberto (Open Access)Determinação do limiar anaeróbio em jogadores de futebol com paralisia cerebral e nadadores participantes da paraolimpíada de Sidney 2000(Sociedade Brasileira de Medicina do Exercício e do Esporte, 2002-06-01) Denadai, Benedito Sérgio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The objectives of this study were: a) to determine the anaerobic threshold (AnT) in soccer players with cerebral palsy and swimmers participant in the Sidney 2000 Paralympic Games and; b) to analyze the behavior of the AnT according to the class of the disabled athletes. 28 disabled athletes participated in the study: 11 soccer players with cerebral palsy (class: F36, F37 and F38) and 17 swimmers (14 men and three women) (class: S1 to S10 and B1). In soccer players, the AnT was determined by an incremental and intermittent protocol in a treadmill. The AnT was identified as the speed corresponding to 3.5 mM of blood lactate. In swimming, the AnT was determined by an incremental and intermittent protocol of 3 x 200 m. After each bout, there was blood collection, and by linear interpolation, the speed corresponding to 4 mM (AnT) was calculated. The maximal aerobic speed (Vamax) and the speed corresponding to the AnT presented a trend of improvement as of the class of the soccer player with cerebral palsy increased. However, the ratio between the speed of AnT/Vamax (approximately 80%) was similar between the classes. In swimming, the speed corresponding to 4 mM increased along with the class, indicating the limitation of functional capacity of the lowest class. However, the lactate concentrations in each percentage of maximal speed of 200 m was very similar between classes, and also that observed in able-bodied swimmers. It can be concluded that the class (and therefore the disability level) interferes in the aerobic functional capacity of disabled athletes. However, the blood lactate response to the submaximal exercise is similar between classes and also to the able-bodied athletes, suggesting the validity of the AnT for aerobic evaluation of swimmers and soccer players with cerebral palsy.
- ItemAcesso aberto (Open Access)Determinação do limiar anaeróbio pela variabilidade da frequência cardíaca de pacientes com DPOC durante exercício em cicloergômetro(Pontifícia Universidade Católica do Paraná, 2012-12-01) Caruso, Flávia Cristina Rossi; Reis, Michel Silva; Siqueira, Ana Cristina Barroso de [UNIFESP]; Gardim, Marli; Catai, Aparecida Maria; Borghi-Silva, Audrey; Universidade Federal de São Carlos Departamento de Fisioterapia Núcleo de Pesquisa em Exercício Físico; Universidade Federal de São Carlos Fisioterapia Cardiovascular; Universidade Federal de São Paulo (UNIFESP); Universidade Federal de São Carlos Geriatria; Universidade de Federal de São Carlos FisioterapiaINTRODUCTION: Chronic Obstructive Pulmonary Disease (COPD) is characterized by structural alterations of lung parenchyma resulting in systemic manifestations. These patients may have marked change in cardiac autonomic control. In this context, studies investigating heart rate variability (HRV) in patients with COPD during physical exercise cycloergometers have been little explored. OBJECTIVE: To determine the anaerobic threshold through HRV in order to establish parameters of evaluation and prescription of exercise intensity in these patients on a cycloergometer. MATERIALS AND METHODS: Eight male patients diagnosed with COPD, mean age 69.5 ± 7.6 years were studied. Heart rate was analyzed at rest and at different intensities of exercise. The test was performed on a cycloergometer and consisted of a warm-up period of four minutes at a minimum power. Steps were performed with initial power of 4W, with increments of 5 in 5W, until the patient reached the anaerobic threshold. RESULTS: Patients that presented higher values of FEV1 showed greater powers during the cycloergometer. Additionally, there was significant reduction in HRV during exercise compared to rest sitting p < 0.05. CONCLUSION: Patients had a severe physical deconditioning reaffirmed the impossibility determined by the anaerobic threshold of 50% of the sample.
- ItemSomente MetadadadosEffect of 12 weeks of training on critical velocity and maximal lactate steady state in swimmers(Taylor & Francis Ltd, 2011-01-01) Machado, Marcus Vinícius; Andries Júnior, Orival; Marques, Alessandro Custódio; Colantonio, Emilson [UNIFESP]; Cyrino, Edilson Seperloni; Mello, Marco Tulio de [UNIFESP]; Fundacao Oswaldo Cruz; Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP); Universidade Estadual de Londrina (UEL)The aim of this study was to determine the effect of 12 weeks of training on the critical velocity and maximal lactate steady state of elite swimmers. the tests to determine critical velocity and maximal lactate steady state were performed before and after 12 weeks of training. Critical velocity after 12 weeks of training was significantly higher than before training (1.45 +/- 0.10 m center dot s-1 vs. 1.41 +/- 0.11 m center dot s-1). in contrast, no significant differences in the velocity at maximal lactate steady state were observed before and after training (1.41 +/- 0.10 m center dot s-1 vs. 1.43 +/- 0.10 m center dot s-1). There was also a decrease in mean lactate concentration after 12 weeks of training. Before training, the velocity at maximal lactate steady state occurred at 100% of critical velocity, with a mean lactate concentration of 4.34 mmol center dot l-1. After training, the velocity at maximal lactate steady state occurred at 98% of critical velocity, with a reduced mean lactate concentration of 3.69 mmol center dot l-1. Based on these results, it would appear that 12 weeks of training was enough to promote an increase in critical velocity. Although no significant differences in the velocity at maximal lactate steady state were observed before and after training, the decrease in mean lactate concentration after training demonstrated greater efficiency of the aerobic system, leading to less wear during the tests.
- ItemSomente MetadadadosEffects of a 30-km race upon salivary lactate correlation with blood lactate(Elsevier B.V., 2006-09-01) Santos, Ronaldo Vagner Thomatieli dos [UNIFESP]; Almeida, A. L. R.; Caperato, E. C.; Martins, E.; Costa Rosa, L. F. B. P.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Blood lactate has been used to determine the aerobic capacity and long distance performance. Recently, a new methodology has been suggested to supplant the invasive blood lactate techniques. Salivary lactate has received attention because it shows high correlation to blood lactate in progressive overload test. We evaluated the correlation between salivary and blood lactate during a long distance run and assessed possible changes in salivary lactate concentration. Fifteen expert marathon racers ran 30 km as fast as possible. Saliva and 25 mu L of blood were collected at rest and at each 6 km for lactate determination. Blood lactate concentration increased in the 6th km and then remained constant until the end of the race. Salivary lactate increased after 18 km in relation to basal. We found high correlations between blood and saliva absolute lactate (r=0.772, p < 0.05) and the blood lactate relative concentration corrected by protein- (r=0.718, p < 0.05). the highest correlation found between absolute and relative salivary lactate was r=0.994 (p < 0.001). Our results show that it is possible to use salivary lactate with absolute values or relative protein concentration. in addition, salivary lactate showed a high correlation with blood lactate in endurance events. (c) 2006 Elsevier Inc. All rights reserved.
- ItemAcesso aberto (Open Access)Estudo comparativo de métodos para a predição do consumo máximo de oxigênio e limiar anaeróbio em atletas(Sociedade Brasileira de Medicina do Exercício e do Esporte, 1999-10-01) Mahseredjian, Fabio [UNIFESP]; Barros Neto, Turibio Leite de [UNIFESP]; Tebexreni, Antonio Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); São Paulo Futebol ClubeThe application of a battery of tests for evaluation of the physical aptitude in laboratory involves a series of highly sophisticated equipment, mainly when the objective is the determination of the aerobic potency (maximum oxygen uptake and anaerobic threshold). The equipment is of high financial cost and requests professionals with good technical and scientific knowledge to handle it, and also, it is impossible to use it in the application of tests in large scale. The analysis of the distance run in a certain period of time or, yet, the time used for a distance set previously, has been a lot used with the goal of estimating or reflecting the aerobic aptitude in children and in adults. The proposal of this study was to analyze the correlation of the Cooper test (CT) with the values of maximum consumption of oxygen (VO2 max) determined through direct method, besides the attempt of validating this field test and another test called the test of 4,000 meters, in anaerobic threshold (AT prediction). Sixty-three players of field soccer were appraised with ages between 15 and 20 years. The athletes were submitted to three tests, one of them was accomplished at the laboratory and the others in the athletics track, in a maximum period of seven days. The laboratory test consisted of the determination of the VO2 max and ventilatory anaerobic threshold (VAT), through analysis of the gaseous changes in a metabolic system analysis on a Vacumed (model CPX Silver edition) Imbramed ergometric treadmill (model ATL 10200), with measurement of the heart rate (HR) with the Polar brand (model Accurex Plus). The first field test followed the protocol determined by Cooper and the second one consisted of a race of 4,000 meters, when determination of the time spent for the preset course was made. The coefficient of linear correlation of Pearson was calculated (r) and the following results were obtained: The speed of LA showed direct significant correlation (r = 0.60 for p < 0.05) with the medium speed in CT. The speed of LA showed direct significant correlation (r = 0.74 for p < 0.05) with the medium speed in T 4000. The VO2 max determined by the direct method did not show significant correlation with the VO2 max (r = 0.23 for p < 0.05) determined through CT. The results suggest that the CT has not the precision required for the prediction of the VO2 max for this population and the possibility of its use for the field tests, like those performed in the present study, in order to obtain the prediction of the anaerobic threshold, and the 4,000 meters test presented larger precision than the CT when the goal is to predict the speed of the anaerobic threshold.
- ItemAcesso aberto (Open Access)Exercise may cause myocardial ischemia at the anaerobic threshold in cardiac rehabilitation programs(Associação Brasileira de Divulgação Científica, 2009-03-01) Fuchs, Angela Rúbia Cavalcanti Neves [UNIFESP]; Meneghelo, Romeu Sergio; Stefanini, Edson [UNIFESP]; De Paola, Angelo Amato Vincenzo [UNIFESP]; Smanio, Paola Emanuela Poggio; Mastrocolla, Luiz Eduardo; Ferraz, Almir Sergio; Buglia, Susimeire; Piegas, Leopoldo Soares; Carvalho, Antonio Carlos [UNIFESP]; Instituto Dante Pazzanese de Cardiologia Serviço de Reabilitação Cardiovascular; Instituto Dante Pazzanese de Cardiologia Seção Médica de Medicina Nuclear; Instituto Dante Pazzanese de Cardiologia Departamento de Saúde; Universidade Federal de São Paulo (UNIFESP)Myocardial ischemia may occur during an exercise session in cardiac rehabilitation programs. However, it has not been established whether it is elicited when exercise prescription is based on heart rate corresponding to the anaerobic threshold as measured by cardiopulmonary exercise testing. Our objective was to determine the incidence of myocardial ischemia in cardiac rehabilitation programs according to myocardial perfusion SPECT in exercise programs based on the anaerobic threshold. Thirty-nine patients (35 men and 4 women) diagnosed with coronary artery disease by coronary angiography and stress technetium-99m-sestamibi gated SPECT associated with a baseline cardiopulmonary exercise test were assessed. Ages ranged from 45 to 75 years. A second cardiopulmonary exercise test determined training intensity at the anaerobic threshold. Repeat gated-SPECT was obtained after a third cardiopulmonary exercise test at the prescribed workload and heart rate. Myocardial perfusion images were analyzed using a score system of 6.4 at rest, 13.9 at peak stress, and 10.7 during the prescribed exercise (P < 0.05). The presence of myocardial ischemia during exercise was defined as a difference ≥2 between the summed stress score and summed rest score. Accordingly, 25 (64%) patients were classified as ischemic and 14 (36%) as nonischemic. MIBI-SPECT showed myocardial ischemia during exercise within the anaerobic threshold. The 64% prevalence of ischemia observed in the study should not be looked on as representative of the whole population of patients undergoing exercise programs. Changes in patient care and exercise programs were implemented as a result of our finding of ischemia during the prescribed exercise.
- ItemAcesso aberto (Open Access)Indexes of power and aerobic capacity obtained in cycle ergometry and treadmill running: comparisons between sedentary, runners, cyclists and triathletes(Sociedade Brasileira de Medicina do Exercício e do Esporte, 2003-08-01) Caputo, Fabrizio; Stella, Sérgio Garcia [UNIFESP]; Mello, Marco Tulio de [UNIFESP]; Denadai, Benedito Sérgio; Universidade Estadual Paulista (UNESP); Universidade Federal de São Paulo (UNIFESP)The objectives of this study were: a) to determine, in a cross-sectional manner, the effect of aerobic training on the peak oxygen uptake (
O2peak), the intensity at O2peak (IO2peak) and the anaerobic threshold (AnT) during running and cycling; and b) to verify if the transference of the training effects are dependent on the analized type of exercise or physiological index. Eleven untrained males (UN), nine endurance cyclists (EC), seven endurance runners (ER), and nine triathletes (TR) were submitted, on separate days, to incremental tests until voluntary exhaustion on a mechanical braked cycle ergometer and on a treadmill. The values of O2peak (ml.kg-1.min-1) obtained in running and cycle ergometer (ER = 68.8 ± 6.3 and 62.0 ± 5.0; EC = 60.5 ± 8.0 and 67.6 ± 7.6; TR = 64.5 ± 4.8 and 61.0 ± 4.1; UN = 43.5 ± 7.0 and 36.7 ± 5.6; respectively) were higher in the group that presented specific training in the modality. The UN group presented the lower values of O2peak, regardless of the type of exercise. This same behavior was observed for the AnT (ml.kg-1.min-1) determined in running and cycle ergometer (ER = 56.8 ± 6.9 and 44.8 ± 5.7; EC = 51.2 ± 5.2 and 57.6 ± 7.1; TR = 56.5 ± 5.1 and 49.0 ± 4.8; UN = 33.2 ± 4.2 and 22.6 ± 3.7; respectively). It can be concluded that the transference of the training effects seems to be only partial, independently of the index (O2peak, IO2peak or AnT) or exercise type (running or cycling). In relation to the indices, the specificity of training seems to be less present in the O2peak than in the IO2peak and the AnT. - ItemAcesso aberto (Open Access)Índices fisiológicos associados com a performance aeróbia em corredores de endurance: efeitos da duração da prova(Sociedade Brasileira de Medicina do Exercício e do Esporte, 2004-10-01) Denadai, Benedito Sérgio; Ortiz, Marcelo Janini; Mello, Marco Tulio de [UNIFESP]; Universidade Estadual Paulista (UNESP); Universidade Federal de São Paulo (UNIFESP)The aim of this study was to assess the validity of the maximal oxygen uptake (VO2max), the velocity at VO2max (vVO2max), time to exhaustion at vVO2max (Tlim), running economy (RE) and anaerobic threshold (AnT) to predict the aerobic performance of the endurance athletes. Fourteen well-trained long-distance runners (33.4 ± 4.4 yr.; 62.7 ± 4.3 kg; 166.1 ± 5.0 cm; VO2max = 60.4 ± 5.9 ml.kg-1.min-1) underwent the following tests: a) simulated competitions in the distances of 1500 and 5000 m and; b) laboratory treadmill tests to determine their VO2max, vVO2max, Tlim, EC and AnT. The velocities (km/h) at vVO2max (18.7 + 0.8), LAn (17.3 + 1.1) v1500 m (19.9 + 0.8) and v5000 m (17.9 + 0.9) were significantly different. A stepwise multiple-regression analysis revealed that AnT alone was the best single predictor of v-5000 m and explained 50% of the variability in 5000 m running velocity. For v1.500 m, Tlim and vVO2max explained 88 % of the variability of the performance. We conclude that, in a group of well-trained long-distance runners, the validity of the physiological indexes (VO2max, vVO2max, Tlim, EC e LAn) to predict the aerobic performance is dependent of the distance (1500 x 5000 m) analyzed.
- ItemAcesso aberto (Open Access)No limiar anaeróbico ventilatório exercício pode causar isquemia miocárdica em programa de reabilitação cardiovascular(Universidade Federal de São Paulo (UNIFESP), 2009-01-28) Fuchs, Angela Rúbia Cavalcanti Neves [UNIFESP]; Carvalho, Antonio Carlos [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Background: Myocardial ischemia may occur during an exercise session in cardiac rehabilitation programs. However, it has not been established whether it is elicited when exercise prescription is based on heart rate corresponding to the anaerobic threshold as measured by cardiopulmonary exercise testing. Objectives: To assess the incidence of myocardial ischemia in cardiac rehabilitation programs according to myocardial perfusion SPECT in exercise programs based on the anaerobic threshold. Methods: Thirty-nine patients (35 men and 4 women) diagnosed with coronary artery disease by coronary angiography and stress technetium-99msestamibi gated SPECT associated with a baseline cardiopulmonary exercise test were assessed. Ages ranged from 45 to 75 years. A second cardiopulmonary exercise testing determined training intensity at the anaerobic threshold. Repeat gated-SPECT was obtained after a third cardiopulmonary exercise testing at the prescribed workload and heart rate. Results: Myocardial perfusion images, analyzed using a score system: 6.4 at rest, 13.9 at peak stress, and 10.7 during the prescribed exercise (p<0.05). The presence of myocardial ischemia during exercise was defined as a difference ³ 2 between the summed stress score and summed rest score. Accordingly, 25 (64%) patients were classified as ischemic and 14 (36%) as nonischemic. Conclusion: MIBI-SPECT has shown myocardial ischemia during exercise within the anaerobic threshold. The 64% prevalence of ischemia observed in the study should not be looked on as representative of the whole population of patients undergoing exercise program. The changes in patient care and exercise program were implemented as a result of our findings (ischemia during the prescribed exercise).
- ItemSomente MetadadadosRespostas metabólicas nos limiares de lactato e anaeróbio, na musculatura esquelética dos membros inferiores de idosas, no teste de Bruce modificado(Universidade Federal de São Paulo (UNIFESP), 2005) Alabarse, Silvio Lopes [UNIFESP]; Ramos, Luiz Roberto [UNIFESP]; Ramos, Luiz Roberto [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Introdução: Atualmente encontramos uma emergente procura de idosas acima de 60 anos de idade pela prática de exercícios físicos. Existe uma grande preocupação dos profissionais da área de saúde em diagnosticar primeiramente a condição física de iniciantes ou já praticantes de atividades físicas, nesta faixa etária, através de um teste ergométrico usado em larga escala, denominado protocolo modificado de Bruce, tendo, em geral, como objetivo, analisar as respostas cardíacas do envolvido, principalmente as eletrocardiográficas, não relatando o comportamento metabólico devido ao estímulo sugerido no teste. Como descrito na literatura, indivíduos jovens, não sedentários, no final de um teste de esforço, apresentam, em geral, o limiar de lactato (LLac 3,5mMol) e respectiva fadiga muscular, após atingirem o limiar anaeróbio I. No entanto, em idosas, deste estudo, suspeitamos que este comportamento não seria o mesmo, também atingiriam o limiar anaeróbio I, porém, na finalização do teste, apresentariam o limiar de lactato com valores inferiores (LLac 2mMol) em relação a indivíduos com menos idade, representado uma fadiga muscular (periférica) precoce em relação a sujeitos jovens. Objetivo: analisar as respostas metabólicas nos limiares de lactato e anaeróbio, na musculatura esquelética dos membros inferiores de idosas, no teste de Bruce modificado. Material e Métodos: Analisamos 16 indivíduos do sexo feminino, com idade média de 69±6 anos através de um teste ergométrico tipo rampa, protocolo modificado de Bruce, em esteira rolante elétrica, com um analisador de trocas gasosas e um lactímetro. Avaliou-se a resposta do lactato sangüíneo, procurando identificar se os sujeitos estavam acima do limiar de lactato fixo de 2mMols ao final do teste em exaustão física, após atingirem o limiar anaeróbio I, representando uma fadiga central e periférica concomitante. Resultados: Os sujeitos envolvidos apresentaram valores de lactato superiores ao limiar de lactato fixo de 2mMols, após estarem acima do limiar anaeróbio I, ao atingirem o maior desempenho físico no protocolo modificado de Bruce. Conclusão: Ao contrário de sujeitos jovens, que apresentam, em geral, fadiga muscular no final de um teste de esforço com valores elevados de lactato sanguíneo, idosas do grupo investigado, como nós esperávamos, demonstraram fadiga na musculatura, com índices menores de lactato, quando ultrapassado o limiar anaeróbio I e o limiar de lactato fixo de 2mMols (p≤0,001), indicando, assim, a ocorrência de fadiga simultânea da musculatura esquelética dos membros inferiores e da capacidade de troca respiratória, devido à acidose metabólica.
- ItemSomente MetadadadosShort term effects of aerobic training in the clinical management of moderate to severe asthma in children(British Med Journal Publ Group, 1999-03-01) Neder, Jose Alberto [UNIFESP]; Nery, Luiz Eduardo [UNIFESP]; Silva, Antonio Carlos da [UNIFESP]; Cabral, Ana Lucia Barros; Fernandes, Ana Luísa Godoy [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Background-Aerobic training has a number of well known beneficial effects in both normal and asthmatic children. However, the impact of training on the clinical management of the underlying bronchial asthma remains controversial, particularly in the most severe patients.Methods-Clinical evaluation, spirometric tests, symptom limited maximum exercise testing, and exercise challenge tests were performed in a group of children with stable moderate to severe asthma. Forty two patients (24 boys) aged 8-16 were evaluated twice: before and after supervised aerobic training (group 1, n = 26) and two months apart (untrained group 2, n = 16).Results-Spirometric and maximal exercise variables in the initial evaluation were significantly reduced in group 1 (p<0.05) but medication and clinical scores and the occurrence of exercise induced bronchospasm (EIB) did not differ between the two groups. Aerobic improvement with training (maximal oxygen uptake and/or anaerobic threshold increment >10% and 100 mi) was inversely related to the baseline level of fitness and was independent of disease severity. Although the clinical score and the occurrence of EIB did not change after training, aerobic improvement was associated with a significant reduction in the medication score and the daily use of both inhaled and oral steroids (p<0.05).Conclusions-Aerobic improvement with Methods training in less fit asthmatic children is related to a short term decrease in the daily use of inhaled and oral steroids, independent of the severity of the disease.
- ItemSomente MetadadadosSuplementação de cafeína atrasa a fadiga(Universidade Federal de São Paulo (UNIFESP), 2014-03-26) Pereira, Paulo Eduardo de Assis [UNIFESP]; Azevedo, Paulo Henrique Silva Marques de [UNIFESP]; http://lattes.cnpq.br/6559911217770194; Universidade Federal de São Paulo (UNIFESP)In this study we demonstrated that caffeine supplementation delays the onset of fatigue, promoting improved performance without inducing changes in autonomic cardiac function, respiratory system and energy metabolism. We conclude that fatigue is regulated by the action of CAF in the central nervous system.