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Is acute static stretching able to reduce the time to exhaustion at power output corresponding to maximal oxygen uptake?

Lopes, Felipe A. Samogin; Menegon, Elton M.; Franchini, Emerson; Tricoli, Valmor Alberto Augusto; Bertuzzi, Rômulo Cássio de Moraes
Fonte: LIPPINCOTT WILLIAMS & WILKINS Publicador: LIPPINCOTT WILLIAMS & WILKINS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
56.16%
Samogin Lopes, FA, Menegon, EM, Franchini, E, Tricoli, V, and de M. Bertuzzi, RC. Is acute static stretching able to reduce the time to exhaustion at power output corresponding to maximal oxygen uptake? J Strength Cond Res 24(6): 1650-1656, 2010-This study analyzed the effect of an acute static stretching bout on the time to exhaustion (T(lim)) at power output corresponding to (V) over dotO(2)max. Eleven physically active male subjects (age 22.3 +/- 2.8 years, (V) over dotO(2)max 2.7 +/- 0.5 L . min(-1)) completed an incremental cycle ergometer test, 2 muscle strength tests, and 2 maximal tests to exhaustion at power output corresponding to (V) over dotO(2)max with and without a previous static stretching bout. The T(lim) was not significantly affected by the static stretching (164 +/- 28 vs. 150 +/- 26 seconds with and without stretching, respectively, p = 0.09), but the time to reach (V) over dotO(2)max (118 +/- 22 vs. 102 +/- 25 seconds), blood-lactate accumulation immediately after exercise (10.7 +/- 2.9 vs. 8.0 +/- 1.7 mmol . L(-1)), and oxygen deficit (2.4 +/- 0.9 vs. 2.1 +/- 0.7 L) were significantly reduced (p <= 0.02). Thus, an acute static stretching bout did not reduce T(lim) at power output corresponding to (V) over dotO(2)max possibly by accelerating aerobic metabolism activation at the beginning of exercise. These results suggest that coaches and practitioners involved with aerobic dependent activities may use static stretching as part of their warm-up routines without fear of diminishing high-intensity aerobic exercise performance.; Mackenzie Presbyterian University (PIBIC-Mackenzie); Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[2008/50934-1]

Estimativa dos metabolismos anaeróbios no déficit máximo acumulado de oxigênio; Estimating of anaerobic metabolisms for maximal accumulated oxygen deficit

Bertuzzi, Rômulo Cássio de Moraes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 04/04/2008 PT
Relevância na Pesquisa
56.27%
O objetivo desse estudo foi averiguar a possibilidade de se estimar os componentes anaeróbios do déficit máximo acumulado de oxigênio (MAOD) utilizando apenas o consumo de oxigênio (VO2). Adicionalmente, foi proposto um método alternativo que não necessita utilizar a extrapolação do VO2 do exercício submáximo para estimar a demanda de O2 para o exercício supramáximo. Para tanto, dez sujeitos fisicamente ativos foram submetidos aos seguintes testes: a) teste progressivo até a exaustão para determinar a carga correspondente ao consumo de oxigênio (WVO2max); b) seis testes de cargas constantes com intensidades abaixo da WVO2max (40-90% WVO2max); c) um teste a 110% da WVO2max; d) teste anaeróbio de Wingate. A fração do metabolismo anaeróbio alático foi estimada pela fase rápida do excesso do VO2 após o exercício (EPOCRÁPIDO), ao passo que a fração do metabolismo anaeróbio lático foi determinada tanto pela diferença entre MAOD e o EPOCRÁPIDO (MAODLA-1) como pelo acúmulo de lactato no sangue (MAODLA-2). O MAODMOD foi calculado pela somatória do EPOCRÁPIDO com MAODLA-2. Os principais resultados foram: a) as estimativas das contribuições do metabolismo anaeróbio lático não eram estatisticamente diferentes (MAODLA-1 = 2...

Evaporative water loss and oxygen uptake in two casque-headed tree frogs, Aparasphenodon brunoi and Corythomantis greeningi (Anura, Hylidae)

deAndrade, D. V.; Abe, Augusto Shinya
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 685-689
ENG
Relevância na Pesquisa
56.05%
Evaporative water loss (EWL) and oxygen uptake ((V) over dot o(2)) was measured in two species of tree frogs with cranial co-ossification, Aparasphenodon brunoi and Corythomantis greeningi. Both species use their head to seal the entrance of bromeliads, tree holes or rocky crevices used as shelters. EWL was significantly reduced in sheltered individuals of both species as compared with those exposed nude to desiccation. EWL per unit area through the head surface was significantly lower than the body skin for A. brunoi but not for C., greeningi. EWL per unit surface area through C. greeningi body skin was about 50% that of A. brunoi, indicating a less permeable skin in the former species. The relationship between cranial coossification and EWL is discussed. ((V) over dot o(2)) in A. brunoi was comparable with other anurans of similar size, whereas in C. greeningi, it was lower than predicted from body mass. Moreover, ((V) over dot o(2)), in C. greeningi showed less sensitivity to temperature increase than in A. brunoi. C. greeningi occurs in a drier environment than A. brunoi, and this appears to be reflected in their EWL and ((V) over dot o(2)) characteristics. (C) 1997 Elsevier B.V.

Oxygen-uptake in snakes - is there a reduction in fossorial species

Wang, T.; Abe, Augusto Shinya
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 483-485
ENG
Relevância na Pesquisa
66.31%
Oxygen uptake of the fossorial blind snake (Typhlops reticulatus) and the semifossorial coral snake (Micrurus ibiboboca) was measured at 20 and 30 degrees C. Oxygen uptake of blind snakes was within the normal range, whereas oxygen uptake of coral snakes was in the lower end of values reported for snakes. The results do not support the hypothesis of reduced oxygen uptake in fossorial reptiles.

ONTOGENIC VARIATION OF OXYGEN-UPTAKE IN THE PITVIPER BOTHROPS MOOJENI (SERPENTES, VIPERIDAE)

Cruzneto, A. P.; Abe, Augusto Shinya
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 549-554
ENG
Relevância na Pesquisa
66.28%
The scaling of oxygen uptake was measured along the ontogeny, in the neotropical pitviper Bothrops moojeni. Allometric relationship between oxygen uptake and body mass, quantified for juveniles, sub-adults and adults, showed the same mass coefficient and exponent. The uniformity of mass constants along ontogeny suggests that B. moojeni is energetically homomorphic. Variation in mass seem to be the sole determinant of oxygen uptake, and structural modifications have no effect on the metabolic rate. Applications of the homomorphism principle to assess variations in mass coefficient and exponent for intraspecific analysis of metabolism in reptiles are discussed. B. moojeni had an oxygen consumption in the range reported for viperids, but lower than that for colubrid snakes of similar size. Possible causative reasons for this pattern is discussed.

Effects of aerobic endurance training status and specificity on oxygen uptake kinetics during maximal exercise

Caputo, F.; Denadai, B.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 87-95
ENG
Relevância na Pesquisa
66.2%
The main purpose of this study was to analyze the effects of exercise mode, training status and specificity on the oxygen uptake ((V)over dot O-2) kinetics during maximal exercise performed in treadmill running and cycle ergometry. Seven runners (R), nine cyclists (C), nine triathletes (T) and eleven untrained subjects (U), performed the following tests on different days on a motorized treadmill and on a cycle ergometer: (1) incremental tests in order to determine the maximal oxygen uptake ((V)over dot O-2max) and the intensity associated with the achievement of (V)over dot O-2max (I(V)over dot O-2max); and (2) constant work-rate running and cycling exercises to exhaustion at I(V)over dot O-2max to determine the effective time constant of the (V)over dot O-2 response (tau(V)over dot O-2). Values for (V)over dotO(2max) obtained on the treadmill and cycle ergometer [R=68.8 (6.3) and 62.0 (5.0); C=60.5 (8.0) and 67.6 (7.6); T=64.5 (4.8) and 61.0 (4.1); U=43.5 (7.0) and 36.7 (5.6); respectively] were higher for the group with specific training in the modality. The U group showed the lowest values for VO2max, regardless of exercise mode. Differences in tau(V)over dot O-2 (seconds) were found only for the U group in relation to the trained groups [R=31.6 (10.5) and 40.9 (13.6); C=28.5 (5.8) and 32.7 (5.7); T=32.5 (5.6) and 40.7 (7.5); U=52.7 (8.5) and 62.2 (15.3); for the treadmill and cycle ergometer...

Anaerobic contribution during maximal anaerobic running test: correlation with maximal accumulated oxygen deficit

Zagatto, A.; Redkva, P.; Loures, J.; Kalva Filho, C.; Franco, V.; Kaminagakura, E.; Papoti, M.
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: E222-E230
ENG
Relevância na Pesquisa
56.21%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); The aims of this study were: (i) to measure energy system contributions in maximal anaerobic running test (MART); and (ii) to verify any correlation between MART and maximal accumulated oxygen deficit (MAOD). Eleven members of the armed forces were recruited for this study. Participants performed MART and MAOD, both accomplished on a treadmill. MART consisted of intermittent exercise, 20 s effort with 100 s recovery, after each spell of effort exercise. Energy system contributions by MART were also determined by excess post-exercise oxygen consumption, lactate response, and oxygen uptake measurements. MAOD was determined by five submaximal intensities and one supramaximal intensity exercises corresponding to 120% at maximal oxygen uptake intensity. Energy system contributions were 65.4 +/- 1.1% to aerobic; 29.5 +/- 1.1% to anaerobic a-lactic; and 5.1 +/- 0.5% to anaerobic lactic system throughout the whole test, while only during effort periods the anaerobic contribution corresponded to 73.5 +/- 1.0%. Maximal power found in MART corresponded to 111.25 +/- 1.33 mL/kg/min but did not significantly correlate with MAOD (4.69 +/- 0.30 L and 70.85 +/- 4.73 mL/kg). We concluded that the anaerobic a-lactic system is the main energy system in MART efforts and this test did not significantly correlate to MAOD.

Oxygen uptake kinetics and time to exhaustion in cycling and running: A comparison between trained and untrained subjects

Caputo, F.; Mello, M. T.; Denadai, B. S.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 461-466
ENG
Relevância na Pesquisa
66.27%
The objective of the present study was to compare pulmonary gas exchange kinetics (VO 2 kinetics) and time to exhaustion (Tlim) between trained and untrained individuals during severe exercise performed on a cycle ergometer and treadmill. Eleven untrained males in running (UR) and cycling (UC), nine endurance cyclists (EC), and seven endurance runners (ER) were submitted to the following tests on separate days: (i) incremental test for determination of maximal oxygen uptake (VO 2max) and the intensity associated with the achievement of VO 2max (IVO 2max) on a mechanical braked cycle ergometer (EC and UC) and on a treadmill (ER and UR); (ii) all-out exercise bout performed at IVO 2max to determine the time to exhaustion at IVO 2max (Tlim) and the time constant of oxygen uptake kinetics (τ). The τ was significantly faster in trained group, both in cycling (EC = 28.2 ± 4.7 s; UC = 63.8 ± 25.0 s) and in running (ER = 28.5 ± 8.5 s; UR = 59.3 ± 12.0 s). Tlim of untrained was significantly lower in cycling (EC = 384.4 ± 66.6 s vs. UC; 311.1 ± 105.7 s) and higher in running (ER = 309.2 ± 176.6 s vs. UR = 439.8 ± 104.2 s). We conclude that the VO 2 kinetic response at the onset of severe exercise, carried out at the same relative intensity is sensitive to endurance training...

Ablation of the ability to control the right-to-left cardiac shunt does not affect oxygen uptake, specific dynamic action or growth in the rattlesnake Crotalus durissus

Leite, Cleo A. C.; Taylor, Edwin W.; Wang, Tobias; Abe, Augusto Shinya; Andrade, Denis Otavio Vieira de
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1881-1889
ENG
Relevância na Pesquisa
66.19%
The morphologically undivided ventricle of the heart in non-crocodilian reptiles permits the mixing of oxygen-rich blood returning from the lungs and oxygen-poor blood from the systemic circulation. A possible functional significance for this intra-cardiac shunt has been debated for almost a century. Unilateral left vagotomy rendered the single effective pulmonary artery of the South American rattlesnake, Crotalus durissus, unable to adjust the magnitude of blood flow to the lung. The higher constant perfusion of the lung circulation and the incapability of adjusting the right-left shunt in left-denervated snakes persisted over time, providing a unique model for investigation of the long-term consequences of cardiac shunting in a squamate. Oxygen uptake recorded at rest and during spontaneous and forced activity was not affected by removing control of the cardiac shunt. Furthermore, metabolic rate and energetic balance during the post-prandial metabolic increment, plus the food conversion efficiency and growth rate, were all similarly unaffected. These results show that control of cardiac shunting is not associated with a clear functional advantage in adjusting metabolic rate, effectiveness of digestion or growth rates. © 2013. Published by The Company of Biologists Ltd.

The decreased oxygen uptake during progressive exercise in ischemia-induced heart failure is due to reduced cardiac output rate

Rolim,N.P.L.; Mattos,K.C.; Brum,P.C.; Baldo,M.V.C.; Middlekauff,H.R.; Negrão,C.E.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2006 EN
Relevância na Pesquisa
66.12%
We tested the hypothesis that the inability to increase cardiac output during exercise would explain the decreased rate of oxygen uptake (VO2) in recent onset, ischemia-induced heart failure rats. Nine normal control rats and 6 rats with ischemic heart failure were studied. Myocardial infarction was induced by coronary ligation. VO2 was measured during a ramp protocol test on a treadmill using a metabolic mask. Cardiac output was measured with a flow probe placed around the ascending aorta. Left ventricular end-diastolic pressure was higher in ischemic heart failure rats compared with normal control rats (17 ± 0.4 vs 8 ± 0.8 mmHg, P = 0.0001). Resting cardiac index (CI) tended to be lower in ischemic heart failure rats (P = 0.07). Resting heart rate (HR) and stroke volume index (SVI) did not differ significantly between ischemic heart failure rats and normal control rats. Peak VO2 was lower in ischemic heart failure rats (73.72 ± 7.37 vs 109.02 ± 27.87 mL min-1 kg-1, P = 0.005). The VO2 and CI responses during exercise were significantly lower in ischemic heart failure rats than in normal control rats. The temporal response of SVI, but not of HR, was significantly lower in ischemic heart failure rats than in normal control rats. Peak CI...

Oxygen uptake during Wingate tests for arms and legs in swimmers and water polo players

Colantonio,Emilson; Barros,Ronaldo Vilela; Kiss,Maria Augusta Peduti Dal Molin
Fonte: Sociedade Brasileira de Medicina do Exercício e do Esporte Publicador: Sociedade Brasileira de Medicina do Exercício e do Esporte
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2003 EN
Relevância na Pesquisa
66.2%
OBJECTIVE: The aim of the present study is to compare the values of the maximal oxygen uptake (O2 max) during two consecutive bouts in Wingate tests for arms and legs in swimmers (S) and water polo players (WP). METHODS: Sample - seven national level athletes (4 S and 3 WP), age 17,90 ± 2,14 years, body mass 71,41 ± 6,84 kg, height 176,65 ± 7,02 cm, % body fat 13,23 ± 4,18. Two Wingate bouts with 30 sec each with 3 min interval between them, for arms and legs in alternated days. Oxygen uptake: breath-by-breath using the gas analysis system K4 b² Cosmed. Statistical analysis: Wilcoxon test for dependent variables and Kolmogorov-Smirnov test for independent variables. RESULTS: The mean values found at the O2 peak (PO2), mean power (MP) and peak power (PP) for each bout of the Wingate test, for arms and legs. For Arms: PO2 = 55.16 ± 5.72 ml.kg-1.min-1...

Oxygen uptake during mineralization of photosynthesized carbon from phytoplankton of the Barra Bonita Reservoir: a mesocosm study

Cunha-Santino,MB.; Gouvêa,SP.; Bianchini Jr,I.; Vieira,AAH.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2008 EN
Relevância na Pesquisa
56.15%
This study aimed to discuss and describe the oxygen consumption during aerobic mineralization of organic products (cells and excretion products) from five unialgal cultures: Cryptomonas sp., Microcystis aeruginosa, Anabaena spiroides, Thalassiosira sp. and Aulacoseira granulata. These species were isolated from Barra Bonita reservoir (22º 29’ S and 48º 34’ W) and cultivated in the laboratory. From each culture, two decomposition chambers were prepared; each chamber contained about 130 mg.L-1 of carbon from water samples of the reservoir. The chambers were aerated and incubated in the dark at 20.0 ºC. The concentration of dissolved oxygen, pH values and electrical conductivity of the solutions were determined during a period of 10 days. The results indicated increases in oxygen consumption for all the solutions studied and also for electrical conductivity. The pH values presented a decreasing tendency throughout the experiment. Oxygen consumption varied from 43 (Aulacoseira granulata chamber) to 345 mg O2 g-1 C (Anabaena spiroides chamber). Decrease in pH values was probably due to increase in CO2 concentration from microbial respiration. Increase in electrical conductivity might be due to the liberation of ions during decomposition. The results demonstrate the potentiality of the studied genera in influencing oxygen availability followed by a die-off event. It also indicates the possibility of changing of the electrical conductivity and pH values in the water column due the aerobic algae mineralization.

Die Kinetik der Sauerstoffaufnahme bei Belastungsbeginn in Relation zum Herzfrequenzanstieg und der alveolären Sauerstoffkonzentration; The kinetics of oxygen uptake at the beginning of exercise in relation to the rise of heart-rate and the oxygen concentration of the alveoles

Zeiselmeier, Annette
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
Relevância na Pesquisa
66.41%
Bisher wurde bei der Betrachtung des Belastungsstoffwechsels das Modell einer direkten Koppelung von pulmonaler Sauerstoffaufnahme mit der muskelzellulären Sauerstoffentnahme ohne Berücksichtigung einer eventuellen Speichermöglichkeit von Sauerstoff im Körper favorisiert. In dieser Arbeit wurde ein Indiz geprüft, welches für eine relevante Nutzung von Speichersauerstoff zu Belastungsbeginn spricht: ein schnellerer Verlauf des Anstiegs der Herzfrequenz zu Belastungsbeginn im Vergleich zum Anstieg der Sauerstoffaufnahme. Es wurde mit Hilfe eines breath-by-breath Spirometersystems und permanenter massenspektrometrischer Gasanalyse sowie fortlaufender Herzfrequenzaufzeichnung ein direkter Vergleich zwischen der Anstiegsgeschwindigkeit der Sauerstoffaufnahme (VO) und der Anstiegsgeschwindigkeit der Herzfrequenz zu Beginn einer mittleren Belastung durchgeführt. 6 freizeitsportlich aktive Probanden aus unterschiedlichen Sportarten absolvierten dabei Laufbandbelastungen bei einer Leistung von 80% ihrer Individuellen Anaeroben Schwelle (IAS) jeweils viermal. Dabei wurde fortlaufend die Herzfrequenz in 5-Sekunden-Intervallen sowie die Sauerstoffaufnahme und end-tidale Sauerstoffkonzentration Atemzug für Atemzug aufgezeichnet. Die Kinetiken der Sauerstoffaufnahme und der Herzfrequenz zeigten erwartungsgemäß einen exponentiellen Anstieg mit nachfolgendem Übergang in einen Steady-State. Der Verlauf der viermaligen Belastungen wurde gemittelt...

The effect of prior exercise intensity on oxygen uptake kinetics during high-intensity running exercise in trained subjects

Nascimento, Paulo Cesar do; Lucas, Ricardo Dantas de; Souza, Kristopher Mendes de; Aguiar, Rafael Alves de; Denadai, Benedito Sergio; Antonacci Guglielmo, Luiz Guilherme
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 147-156
ENG
Relevância na Pesquisa
66.12%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The aim of this study was to compare the effects of two different kinds of prior exercise protocols [continuous exercise (CE) versus intermittent repeated sprint (IRS)] on oxygen uptake (VO2) kinetics parameters during high-intensity running.Thirteen male amateur futsal players (age 22.8 +/- A 6.1 years; mass 76.0 +/- A 10.2 kg; height 178.7 +/- A 6.6 cm; VO2max 58.1 +/- A 4.5 mL kg(-1) min(-1)) performed a maximal incremental running test for the determination of the gas exchange threshold (GET) and maximal VO2 (VO2max). On two different days, the subjects completed a 6-min bout of high-intensity running (50 % a dagger) on a treadmill that was 6-min after (1) an identical bout of high-intensity exercise (from control to CE), and (2) a protocol of IRS (6 x 40 m).We found significant differences between CE and IRS for the blood lactate concentration ([La]; 6.1 versus 10.7 mmol L-1, respectively), VO2 baseline (0.74 versus 0.93 L min(-1), respectively) and the heart rate (HR; 102 versus 124 bpm, respectively) before the onset of high-intensity exercise. However, both prior CE and prior IRS significantly increased the absolute primary VO2 amplitude (3.77 and 3.79 L min(-1)...

The importance of perivitelline fluid convection to oxygen uptake of Pseudophryne bibronii eggs

Mueller, C.; Seymour, R.
Fonte: Univ Chicago Press Publicador: Univ Chicago Press
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
Relevância na Pesquisa
56.16%
The ciliated epithelium of amphibian embryos produces a current within the perivitelline fluid of the egg that is important in the convective transfer of oxygen to the embryo's surface. The effects of convection on oxygen uptake and the immediate oxygen environment of the embryo were investigated in Pseudophryne bibronii. Gelatin was injected into the eggs, setting the perivitelline fluid and preventing convective flow. Oxygen consumption rate (M(.)o₂) and the oxygen partial pressure (Po₂) of the perivitelline fluid were measured in eggs with and without this treatment. M(.)o₂ decreased in eggs without convection at Gosner stages 17-19 under normoxia. The lack of convection also shifted embryos from regulators to conformers as environmental Po₂ decreased. A strong Po₂ gradient formed within the eggs when convection was absent, demonstrating that the loss of convection is equivalent to decreasing the inner radius of the capsule, an important factor in gas exchange, by 25%. M(.)o₂ also declined in stage 26-27 embryos without cilia-driven convection, although not to the extent of younger stages, because of muscular movements and a greater skin surface area in direct contact with the inner capsule wall. This study demonstrates the importance of convective flow within the perivitelline fluid to gas exchange. Convection is especially important in the middle of embryonic development...

Accuracy of six minute walk test, stair test and spirometry using maximal oxygen uptake as gold standard

Cataneo,Daniele Cristina; Kobayasi,Shoiti; Carvalho,Lídia Raquel de; Paccanaro,Rafael Camargo; Cataneo,Antonio José Maria
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2010 EN
Relevância na Pesquisa
56.05%
PURPOSE: To assess the accuracy of the variables stair climbing time (SCt), stair climbing power (SCP), six-minute walk test distance (6MWT), and forced expiratory volume in 1 second (FEV1) using maximal oxygen uptake on exercise (VO2max) as the gold standard. METHODS: Tests were performed in 51 patients. FEV1 was measured by spirometry and 6MWT was performed in a flat 120-m corridor. Stair climbing test was performed on a 6-flight stairway to obtain SCt and SCP. VO2max was measured by ergospirometry, using the Balke protocol. Pearson's linear correlation and p values were calculated between VO2max and the other variables tested. For accuracy calculations, variable cutoff points were obtained through receiver operating characteristic (ROC) curves, dividing individuals into normal or unhealthy. Kappa statistic was used to calculate concordance. RESULTS: Accuracy was: SCt - 86%, 6MWT - 80%, SCP - 71%, FEV1(L) - 67%, FEV1(%) - 63%. SCt and 6MWT showed 93.5% sensitivity when combined in parallel, and 96.4% specificity in series. CONCLUSION: SCt presented the best accuracy. SCt and 6MWT combined showed nearly 100% sensitivity or specificity. Thus, these simple exercise tests should be more routinely used, especially when an ergospirometer is not available to measure VO2max.

Oxygen uptake during mineralization of humic substances from Infernão Lagoon (São Paulo, Brazil)

Cunha-Santino,M. B.; Bianchini JR.,I.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2004 EN
Relevância na Pesquisa
66.3%
Assays were carried out to evaluate the dissolved oxygen uptake resulting from mineralization of humic substances (fulvic acid (FA) and humic acid (HA)) from different sources: sediment, dissolved organic matter (DOM) of 120-day decomposed aquatic macrophyte (Scirpus cubensis and Cabomba piauhyensis), and lagoon DOM. The experiments were also aimed at estimating the oxygen uptake coefficient of the mineralization. About 20-30 mg of substrate were added to 1.1 liters of water from Infernão Lagoon (21º33' to 21º37'S; 47º45' to 47º51'W). The solutions were aerated and the dissolved oxygen (DO) was monitored during 40 days. Dissolved organic carbon (DOC) and particulate organic carbon (POC) were estimated after 80 days of the experiment. Anaerobic processes were avoided by aerating the solutions. The results were fitted to a first-order kinetics model, from which the uptake of oxygen parameters was obtained. Oxygen consumption (OC) ranged from 4.24 mg L-1 (HA - S. cubensis) to 33.76 mg L-1 (FA - sediment). The highest deoxygenation coefficient (kD) was observed during mineralization of FA - DOM (0.299 day-1), followed in decreasing order by FA - S. cubensis, HA - sediment, HA - S. cubensis, FA - sediment, and FA - C. piauhyensis (0.282; 0.255; 0.178; 0.130...

COPD patients' oxygen uptake and heart rate on-kinetics at cycle-ergometer: correlation with their predictors of severity

Pessoa,Bruna V.; Beltrame,Thomas; Lorenzo,Valéria A. Pires Di; Catai,Aparecida M.; Borghi-Silva,Audrey; Jamami,Mauricio
Fonte: Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia Publicador: Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2013 EN
Relevância na Pesquisa
66.12%
OBJECTIVES: To assess whether there is a correlation between oxygen uptake (VO2) and heart rate (HR) on-kinetics in the constant-load cycle-ergometer test (CLT) and the BODE index and its isolated variables in patients with chronic obstructive pulmonary disease (COPD). METHOD: Fourteen male patients between 55 and 78 years of age with moderate to severe COPD were evaluated. Each patient underwent spirometry, the six-minute walk test (6MWT), the cycle-ergometer incremental test (IT) and CLT on alternate days. The exhaled gases were collected, and the VO2 and HR on-kinetics were analyzed. The BODE index was calculated. RESULTS: It was noted that the VO2 tau (τ) and mean response time (MRT) were significantly higher than HR τ and MRT. Moderate and strong correlations between τ and MRT of the VO2 and HR and the BODE index was noted (r=0.75 and r=0.78; r=0.62 and r=0.63, respectively), and there were correlations between the VO2 τ and MRT and the forced expiratory volume in one second (FEV1) (r=-0.60; r=-0.53) and the distance traveled at 6MWT (DT-6MWT) (r=-0.61; r=-0.44) and DT-6MWT % predicted (r=-0.62; r=-0.46). The HR τ and MRT were correlated with DT-6MWT (r=-0.59; r=-0.58) and DT-6MWT % predicted (r=-0.62; r=-0.62). CONCLUSION: The slowing of cycle-ergometer VO2...

Oxygen uptake kinetics during supra-maximal exercise: Mathematical modelling; Cinética do consumo de oxigênio durante exercícios supramáximos: Aplicação de modelos matemáticos

Hirai, Daniel Müller; Universidade Estadual de Londrina – Londrina, PR. Brazil; Okuno, Nilo Massaru; Universidade Estadual de Londrina; Perandini, Luiz Augusto Buoro; Universidade Estadual de Londrina; Puga, Guilherme Morais; Universidade Católica de
Fonte: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil Publicador: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; "Avaliado por Pares",; ; Avaliado por Pares; Descritiva Formato: application/pdf; application/pdf
Publicado em 18/07/2008 POR; ENG
Relevância na Pesquisa
66.31%
http://dx.doi.org/10.5007/1980-0037.2008v10n1p43Precise estimation of oxygen uptake kinetics parameters is essential to understand its control and/or limit uptake mechanisms. The purpose of the present study was to characterize the oxygen uptake kinetics responses during supramaximal cycle ergometer exercise using two modeling techniques. Eleven male subjects (age = 25.4 ± 4.9 years, height = 177.0 ± 4.0 cm, mass = 77.1 ± 11.3 kg, VO2max = 40.3 ± 6.3 mL.kg-1.min-1) performed a series of square- have exercise transitions to exhaustion at intensities equivalent to 100, 113, 133 and 153% of VO2max. The time constant of the primary component was estimated with an exponential and semi-logarithmic model, comparisons were made using repeated measures ANOVA and the Tukey post hoc tests, with statistical signifi cance accepted when p<0.05. In order to calculate the time constant by the semi-logarithmic model it is necessary to estimate oxygen demand, which was performed by means of a regression procedure. The exponential model resulted in lower values for the time constant (35.1 ± 8.0s; 32.5 ± 7.4s; 29.6 ± 11.3s; 25.3 ± 7.5s) compared to the semi-logarithmic model (107.9 ± 27.1s; 104.5 ± 24.3s; 114.1 ± 30.4s; 125.3 ± 24.9s) at all intensities. The observation of this confl icting oxygen uptake kinetics behavior depending upon which mathematical model is applied suggests that physiological inferences on the basis of parameters obtained during supra-maximal exercise should be made with caution.; A correta estimativa dos parâmetros da cinética do consumo de oxigênio é fundamental para a interpretação de seus mecanismos de controle e/ou limitação. O objetivo deste estudo foi caracterizar a cinética do consumo de oxigênio em intensidades supra-máximas realizadas em cicloergômetro a partir da utilização de dois modelos matemáticos distintos. Onze indivíduos saudáveis do sexo masculino (idade = 25...

Oxygen uptake during the exercise: temporal aspectos and adjustments of curves; Consumo de oxigênio durante o exercício físico: aspectos temporais e ajustes de curvas

Silva, Adriano Eduardo Lima; Laboratório de Pesquisa Morfo-Funcional - CEFID/UDESC; Oliveira, Fernando Roberto de; Laboratório de Pesquisa Morfo-Funcional - CEFID/UDESC
Fonte: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil Publicador: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; "Avaliado por Pares","Artigo Solicitado"; "Avaliado por Pares", "Artigo Solicitado"; Bibliográfica Formato: application/pdf; application/pdf
Publicado em 20/06/2006 POR; ENG
Relevância na Pesquisa
66.34%
The oxygen uptake has been considered as one of the most important physiological variables for exercise physiology. The first models relating oxygen uptake with performance emerged in the beginning of last century and it has been intensely discussed in the literature until today. This review discussed some topics about oxygen uptake, more specifically on aspects related with the kinetic and influences of the time response of this variable on the adjustment curve during an incremental test. Discussion on the level of aerobic condition and exercise intensity on the kinetics of oxygen uptake are also included in the text. Finally, verification on the slow component and on the physiological control of the oxygen uptake kinetics is also presented.; O consumo de oxigênio tem sido considerado uma das variáveis fisiológicas mais importantes para a fisiologia do exercício. Os primeiros modelos relacionando o consumo de oxigênio com o desempenho esportivo surgiram no inicio do século passado e continua sendo intensamente discutido na literatura atual. A presente revisão discutiu alguns tópicos sobre consumo de oxigênio, mais especificamente sobre aspectos relacionados à cinética e a influencia do tempo de resposta dessa variável sobre os ajustes de curva em teste progressivo. Discussões relacionadas a influencia do nível de aptidão aeróbia e a intensidade do exercício sobre a cinética do consumo de oxigênio também estão inseridas no texto. Por fim...