No description available.

Purpose: This is the first study done to determine the efficacy of 10-weeks of Nexersys training on improving cardiovascular fitness (CF) and body composition (BC). Nexersys is an "exergaming" system that combines mixed martial arts, high-intensity interval training and core work into an interactive unit with a monitor and 7-strike pads. Participants were provided a Nexersys unit in their homes to complete 10-weeks of training 3 to 4 times a week progressing from 5, 3-min rounds with a minute rest to 15 rounds at the end of 10-weeks. Participants were tested on 3 separate occasions, prior to beginning training (0wk), at 5-weeks (5wk) and 10-weeks (10wk). Body mass (BM), percent body fat (%BF), fat mass (FM) and lean mass (LM) were assessed using dual-energy X-ray absorptiometry (DEXA). CF was assessed during a 10-round Nexersys bout (NB) and a VO2max treadmill (VO2max) test. CF during NB and VO2max treadmill test was assessed by using regression analysis to determine the estimated average heart rate for a range of VO2 10-25 ml/kg/min (HRN) and 10-30 ml/kg/min (HRV) respectively. Results and Conclusion: Relative to starting values, BM did not change (79.8 ± 7.9 to 79.7 ± 7.5 kg). %BF and FM decreased from starting values (36.0 ± 3.4% to 34.1 ± 5.3%, p=0.003 and 30.0 ± 4.9 kg to 28.4 ± 4.6 kg, p=0.045, respectively). LM increased from starting values (46.7 ± 3.5kg to 48.4 ± 3.6kg, p=0.001). HRN and HRV decreased from starting (148 ± 2.7 to 140.8 ± 1.9 bpm, p=0.003 and 148 ± 1.8 to 140.1 ± 1.8 bpm, p=0.003, respectively). VO2max trended to increase but did not reach statistical significance (33.9 ± 1.7 to 36.3 ± 1.7 ml/kg/min, p=0.054). These findings suggest 10-weeks of Nexersys training improves body composition both by increasing LM and decreasing BF with no change in BM. CF improved at submaximal intensities. / text

No description available.

No description available.

Objective: To assess the effects of wearing a protective mouthguard during exercise on ventilation and oxygen consumption. Design and Setting: All participants performed a graded maximal exercise test on a cycle ergometer to determine peak oxygen consumption (VO2peak). Each participant also performed 6 submaximal exercise tests while wearing one of two facemasks (nasal or non-nasal breathing) and one of three mouthguard conditions (no mouthguard, boil and bite, custom-fit). Steady-state VO2, rate of perceived exertion (RPE), and other ventilatory values were measured at 60% and 80% of VO2max during each submaximal exercise test. All 6 submaximal exercise tests were completed within a 2-week period using a randomized 6x6 balanced Latin square design. Subjects: Twenty-four subjects (age = 20.41 ± 1.99) who were members of the Brigham Young University lacrosse team participated in this study. Measurements: Data were analyzed using a random coefficients growth curve. The full models for all variables included fixed effects for mask, work level, mouthguard, time, and all interactions of the above. Full models were also assumed to have random subject coefficients for the intercepts and slopes relative to time. Results: For VO2 there was a significant effect for facemask type (p<.0001, F = 24.30, df = 1680), mouthguard (p = .0177, F = 4.04, df = 1680), and work (p<.0001, F = 5428.16, df = 1680). For VO2 there was also a significant interaction for mask*work (p = .0280, F = 4.84, df = 1680). For RPE there was a significant effect for facemask type (p = .0005, F = 12.28, df = 1657) and for work (p<.0001, F = 4040.53, df = 1657). For RPE there were also significant interactions for mask*mouthguard (p<.0001, F = 11.82, df = 1657) and for mask*work (p<.0001, F = 18.88, df = 1657). For VE there were significant interactions for mask (p< 0.0001, F = 16.49, df = 1680), mouthguard (p < 0.0001, F = 19.98, df = 1680), and work (p < 0.0001, F = 9122.33, df = 1680). For VE there were also significant interactions for mask*mouthguard (p < 0.002, F = 6.25, df = 1680), and mask*work (p < 0.0001, F = 17.77, df = 1680). Conclusions: Although statistical significance was found for a number of effects, we speculate that the very small differences in the physiological responses to wearing a mouthguard are of little practical significance and would not effect performance. Wearing a mouthguard during exercise does not alter physiological responses and complaints of reduced ventilation are probably psychological.

Made available in DSpace on 2014-06-11T19:22:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-04-29Bitstream added on 2014-06-13T20:49:23Z : No. of bitstreams: 1 machado_cep_me_rcla.pdf: 485625 bytes, checksum: fb01231ed1afbdc33006414cd73d2b07 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O surgimento de equipamentos que permitem a análise do consumo de oxigênio (VO2) respiração-a- respiração, tem despertado um grande interesse nos fatores que podem influenciar sua cinética no início do exercício (resposta on). Entre os fatores mais estudados, temos a intensidade do exercício e o nível do treinamento dos sujeitos. Estes dados sugerem que a influência do exercício prévio sobre o VO2 durante o exercício incremental só ocorreria em baixas intensidades de esforço (< 60% VO2max). Os objetivos deste estudo foram: a) analisar a influência do exercício supramáximo realizado previamente, sobre os parâmetros da cinética do VO2 durante a transição repouso-exercício realizado a 50 e 70% VO2max, e b) analisar a influência do exercício supramáximo realizado previamente sobre as respostas cardiorrespiratórias e metabólicas durante o exercício de carga constante realizado a 50 e 70% VO2max. Para este estudo foram utilizados 14 ciclistas bem treinados do sexo masculino (VO2max = 63,4 + 6,5 ml.kg-1.min-1; idade = 21,4 + 3,5 anos; massa corporal = 68,1 + 6,8 kg; estatura = 174,9 + 4,6 cm) que executaram cinco testes: 1) exercício contínuo progressivo até a exaustão voluntária para a determinação do VO2max e as cargas correspondentes a 50, 70 e 120% VO2max e; 2) Quatro testes de carga constante, executados de forma aleatória e em dias separados. Nestes testes os sujeitos pedalaram durante 20 minutos em duas diferentes intensidades de exercício (50 e 70% do VO2max), realizados com e sem a execução prévia de um exercício supramáximo (120% VO2max). Foi analisada a resposta on do VO2 e também as respostas cardiorrespiratórias e metabólicas durante 20 minutos de exercício com carga constante realizados a 50 e 70% VO2max... / The appearance of an equipment that permits the oxygen consumption analysis (VO2) breath by breath has arisen a huge interest in factors which can influence its dynamics in the beginning of exercise (on response). Among the more studied factors, are the exercise intensity and training status. Meanwhile, few studies have analyzed the possible effects of previous exercise on the VO2response during exercise at moderate domain. In our lab, we have verified recently that during an incremental test performed eight minutes after a supramaximum exercise (120% VO2max), there was a significant VO2 increase in the first stage, while, at the intensities between 60% and VO2max, no alteration of VO2 was found, in accordance with the results existent in the literature. These results suggest that the influence of a previous exercise on the VO2 during the incremental exercise would just occur at low intensities (< 60% VO2 max). This model, meanwhile, does not permit to isolate a possible time effect of the exercise, once the highest intensities were always done after two or three stages, which could have favored a recovery, at least partially, of the metabolic conditions. In this way, the data until the present moment do not permit to identify if the normalization of VO2 during the incremental exercise is more dependent on the time and/or the exercise intensity. Therefore, the aims of this study were: a) to analyze the influence of the previous supramaximum exercise on the VO2 kinetics during the rest-exercise transition carried out at 50 and 70% VO2max, and b) to analyze the influence of the previous supramaximum exercise on the cardiorespiratory and metabolic responses during the constant loading exercise performed at 50 and 70% VO2max... (Complete abstract, click eletronic address below)

Made available in DSpace on 2014-06-11T19:22:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-17Bitstream added on 2014-06-13T18:08:44Z : No. of bitstreams: 1 figueira_tr_me_rcla.pdf: 369273 bytes, checksum: 78be44f75df9ba9856f75c31056f5ad3 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste estudo foi analisar a influência do estado de treinamento aeróbio sobre os efeitos do exercício prévio nos parâmetros da cinética do consumo de oxigênio (VO2) durante o exercício moderado. Para isto, 14 voluntários não treinados (GNT: massa corporal, 81,2 + 10,3 kg; estatura, 1,78 + 0,07 m; idade, 21,2 + 4,0 anos) e outros 14 ciclistas treinados (GT: massa corporal, 68,2 + 6,9 kg; estatura, 1,75 + 0,05 m; idade, 21,4 + 3,5 anos) (indivíduos com no mínimo dois anos de engajamento no treinamento e competições) realizaram um teste progressivo até a exaustão voluntária para a determinação do VO2 máximo (VO2max) e do limiar de lactato (LL). Posteriormente, realizaram em diferentes dias e em ordem aleatória, duas transições repouso-exercício (seis minutos na carga correspondente a 80% do LL), sendo uma delas precedida em oito minutos pelo exercício prévio (dois tiros de um minuto na carga correspondente a 120% VO2max, com um minuto de recuperação entre eles). Durante estes testes foram coletadas amostras de sangue capilar para a determinação da concentração de lactato sanguíneo e também monitoradas as variáveis cardiopulmonares a cada incursão ventilatória. O VO2 de repouso foi aumentado (p < 0,05) pelo exercício prévio (EPS) em ambos os grupos (GNT: 0,836 + 0,061 vs. 0,506 + 0,194 L/min; GT: 0,373 + 0,055 vs. 0,577 + 0,137 L/min). O tempo da resposta média do VO2 (constante tempo da resposta geral 0-360 s) foi significantemente reduzido na condição EPS apenas para o GNT (32,9 + 7,4 vs. 28,6 + 7,7 s; p < 0,05; GT: 25,7 + 5 vs. 23,3 + 5,8 s; p > 0,05). No GT, a Assimptota (VO2 médio dos últimos dois min de exercício) mostrou-se significantemente... / The aim of this study was to analyze the influence of aerobic fitness on the effects of prior exercise on VO2 kinetics parameters during moderate-intensity exercise. Fourteen untrained subjects (UG: body mass, 81.2 + 10.3 kg; height, 1.78 + 0.07 m; age, 21.2 + 4.0 years) and fourteen well trained cyclists (TG: body mass, 68.2 + 6.9 kg; height, 1.75 + 0.05 m; age, 21.4 + 3.5 years) (more than two years of engagement in endurance training and competition) performed one incremental test to voluntary exhaustion, in order to determine the lactate threshold (LT) and maximal VO2 (VO2max). Thereafter, they performed in different days and in random order, two rest to moderate-intensity exercise transitions (six minutes at 80% of LT), preceded by either no prior exercise or prior supra-maximal exercise (two bouts of one min at 120% of VO2max, with rest of one min between them). During the tests, capillary blood samples were collected to determine lactate concentration and the pulmonary gas exchanges were monitored continuously breath-by-breath. Resting VO2 was significantly (p < 0.05) increased by prior exercise (EPS) in both groups (UG, 0.836 + 0.061 vs. 0.506 + 0.194 L/min; TG, 0.373 + 0.055 vs. 0.577 + 0.137 L/min). Mean response time (time constant of overall VO2 response - 0 - 360 s) was significantly speeded by EPS in untrained group (UG: 32.9 + 7.4 vs. 28.6 + 7.7 s, p < 0.05; TG: 25.7 + 5.0 vs. 23.3 + 5.8 s, p > 0.05). In the trained group, the Assimptota (mean last two minutes VO2 value of moderate exercise) was significantly increased by EPS (TG: 2.208 + 0.383 vs. 2.067 + 0.266 L/min, p < 0.05; UG: 1.600 + 0.269 vs. 1.600 + 0.292 L/min, p > 0.05). It can be concluded... (Complete abstract click electronic access below)

Made available in DSpace on 2016-12-06T17:07:27Z (GMT). No. of bitstreams: 1 Guilherme.pdf: 1016769 bytes, checksum: 70d826dd20233346aa060ce58783d5ec (MD5) Previous issue date: 2011-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present study aimed to evaluate the effects of ischemic preconditioning (IPC) on the ventilatory parameters kinetics in different exercise intensities. Twelve physically active subjects (23.1±1.7 years; 176.1±4.6 cm; 77.6±8.3 kg; 46,7±5,7mL&#8729;kg-1&#8729;min-1) underwent in 5 different days the following tests in an electronically braked cycle ergometer: 1) incremental exercise test until maximal voluntary exhaustion in order to determine maximal oxygen uptake (VO2máx), ventilatory threshold (VT). 2) two constant work rate bouts (CWR) of 6min at moderate intensity (80%VT) interspersed with 30 min of intervention with the IPC (3x5min occlusion/3x5min reperfusion for each thigh, performed intermittently and alternately) in two different days; 3) two repetitions of 6 min CWR in severe intensity corresponding to 70%&#8710; (i.e., VT + 0,7 x (VO2máx VT)) interspersed by 45min passive rest followed by CPI, in two different days. IPC significantly decreased both the primary component time constant (t1) (19.2±3.3s to 14.8±3,6s) and carbohydrate oxidation (1.43±0.32g&#8729;min-1 to 1.16±0.33g&#8729;min-1) and increased fat oxidation (0.27±0.12g&#8729;min-1 to 0.40±0.12g&#8729;min-1) the for moderate intensity with the VO2 t1 (25,4±9s to 21,2±6,6s) and end VO2 (1689,1±291 para 1745,9±255,7mL&#8729;min-1) did not differ significantly. In severe intensity IPC significantly reduced both t1 (19.2±3.3s to 14.8±3.6s; p<0.05) and end blood lactate concentration (7.48±2.58mM to 7.01±2.20mM, p<0.05), however the slow component amplitude (502,5±204,1 to 529,1±133,5mL&#8729;min-1) and end VO2 (3406,5±474,4 to 3489,7±435,6 mL&#8729;min-1) of VO2 kinetics remain similar. We conclude that the primary component of VO2 kinetics was accelerated by IPC during severe exercise, but not during moderate exercise, suggesting that the main effect of IPC seems to be the increase on O2 delivery induced by a higher blood flow, which corroborate with the periphery limitation hypothesis (metabolic inertia) as the main limit factor for VO2 kinetics at the onset of moderate exercise. For moderate exercise, IPC increased the CO2 retention becoming the VO2 kinetics even slower because the decrease of HCO3- content by ischemia, furthermore, the changes on substrate oxidation observed during exercise after IPC might have occurred for reperfusion-induced increases in FFA delivery and &#946;-oxidation pre-activation / O objetivo deste estudo foi avaliar os efeitos da condição pré-isquêmica (CPI) na cinética dos parâmetros ventilatórios em diferentes intensidades de exercício. Doze indivíduos (23,1±1,7 anos; 176,1±4,6 cm; 77,6±8,3 kg; 46,7±5,7mL&#8729;kg-1&#8729;min-1) fisicamente ativos realizaram em 5 dias diferentes os seguintes testes em cicloergômetro de frenagem eletromagnética: 1) teste de carga incremental até exaustão voluntária para determinação das variáveis máximas (consumo máximo de oxigênio, VO2máx) e submáximas (Limiar Ventilatório, LV); 2) em dois dias diferentes duas repetições de exercício em carga constante (PCC) com 6min de duração em intensidade moderada a 80%LV intercalados com 30min de intervenção com o CPI (3x5min de oclusão/3x5 de reperfusão para cada coxa, de maneira intermitente e alternada); 3) em dois dias diferentes duas repetições de PCC de 6 min em intensidade severa correspondente a 70% do valor entre o VO2 no LV e o VO2máx (70%&#8710;, i.e. LV + 0.7x(VO2max LV)) intercalados por 45min de repouso passivo seguidos do protocolo de CPI. Na carga moderada as variáveis que apresentaram diferença significante da condição controle para a experimental foram: a constante de tempo do componente primário (t1) do VCO2 (43,4±10,4s para 58,2±18,5s), a oxidação de carboidratos (1,43±0,32g&#8729;min-1 para 1,16±0,33g&#8729;min-1) e a oxidação de gordura (0,27±0,12g&#8729;min-1 para 0,40±0,12g&#8729;min-1). O t1 do VO2 (25,4±9s para 21,2±6,6s) e o VO2 final (1689,1±291 para 1745,9±255,7mL&#8729;min-1) não apresentaram diferença significante no domínio moderado. No domínio severo o CPI acelerou significativamente o t1 (19,2±3,3s para 14,8±3,6s) e reduziu a concentração sanguínea final de lactato (7,48±2,58 mM para 7,01±2,20mM) não alterando a amplitude do componente lento (502,5±204,1 para 529,1±133,5mL&#8729;min-1) e o VO2 final (3406,5±474,4 para 3489,7±435,6 mL&#8729;min-1). Podemos concluir que a cinética do componente primário do VO2 (t1) foi acelerada após o CPI no exercício severo, sem efeitos sobre a cinética do VO2 durante o exercício moderado, sugerindo que o principal efeito do CPI parece residir sobre o aumento da oferta de O2 induzida pelas modificações no fluxo sanguíneo, corroborando com a hipótese da limitação periférica (inércia oxidativa) como principal determinante na cinética do VO2 ao início do exercício moderado. No domínio moderado, o CPI aumentou a retenção de CO2 e consequentemente tornou mais lenta a cinética do VCO2 no músculo como conseqüência da diminuição de HCO3- pela isquemia, além disso, a alteração na oxidação de substratos observada durante o exercício subseqüente o CPI provavelmente ocorreu pela maior oferta de AGL e ativação da &#946;-oxidação induzidos pelos períodos de reperfusão

The purpose of this investigation is to examine the energy demand of heavy metal drummers during rehearsal in order to understand the physiological responses. This information may lead to a better understanding of energy expenditure and add to the compendium of physical activity. The investigation consisted of eight apparently healthy 20 to 37-year-old males were recruited for this investigation. Information gathered during the drum test was average VO2, VO2peak, HR in beats per minute (bpm), metabolic equivalents (METs), and energy expenditure (EE) expressed in calories (kcals) per minute and per hour. Rating of perceived exertion (RPE) was used in addition to VO2 and HR values to assess physical demand. The Bruce Protocol maximal treadmill test was administered to compare the participants VO2max to their VO2peak while drumming. The EE during the 40-minute drum test was 387.05 + 83 kcals with an estimated hourly EE of 567.33 + 111.7 kcals. VO2, VO2peak, VE, and HR was 21.4 + 4.1 ml/kg/min, 33.9 + 8.1 ml/kg/min, 63.5 + 19 L/min, and 150.4 + 13.6 bpm respectively. The average MET level reached was six. RPE was 13.8 + 1.2 and is expressed as “somewhat hard” in difficulty according to the ACSM. Those categorized as having an average level of fitness reached 50-59% of their VO2max while the two individuals categorized as having an excellent level of fitness reached 42-45% of their VO2max. In conclusion, heavy metal drumming is a form of physical activity that is of moderate intensity and can be compared to other forms of recreational and work related physical activity.

There has been an interest in the kinetics of the V02 response during exercise at various intensities. However, most studies focus on the response of submaximal intensities whereas few studies have examined V02 kinetics at severe intensities. The purpose of this study was to evaluate the effect of exercise intensity on V02 kinetics over a range of severe intensities.