981 resultados para Aerobic performance
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Universidade Estadual de Campinas . Faculdade de Educação Física
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Santhiago, V, da Silva, ASR, Papoti, M, and Gobatto, CA. Responses of hematological parameters and aerobic performance of elite men and women swimmers during a 14-week training program. J Strength Cond Res 23(4): 1097-1105, 2009-The main purpose of the present investigation was to verify the responses of hematological parameters in men and women competitive swimmers during a 14-week training program. Twenty-three Olympic and international athletes were evaluated 4 times during the experiment: at the beginning of the endurance training phase (T1), at the end of the endurance training phase (T2), at the end of the quality phases (T3), and at the end of the taper period (T4). On the first day at 8:00 AM, each swimmer had a blood sample taken for the determination of hematological parameters. At 3:00 PM, the athletes had their aerobic performance measured by anaerobic threshold. On the second day at 8: 00 AM, the swimmers had their aerobic performance measured by critical velocity. Hematocrit and mean corpuscular volume diminished (p <= 0.05) from T1 to T2 (men: 5.8 and 7.2%; women: 11.6 and 6.8%), and increased (p <= 0.05) from T2 to T3 (men: 7.2 and 6.0%; women: 7.4 and 5.2%). These results were related to the plasma volume changes of the athletes. However, these alterations do not seem to affect the swimmers` aerobic performance. For practical applications, time-trial performance is better than aerobic performance (i.e., anaerobic threshold and critical velocity) for monitoring training adaptations.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Introduction - the aim of this study was to analyze the validity of the critical speed (CS) to determine the speed corresponding to 4 mmol 1(-1) of blood lactate (S4) and the speed in a 30 min test (S30min) of swimmers aged 10-15 years.Synthesis of facts - CS, S4 and S30min were determined in 12 swimmers (eight boys and four girls) divided into two groups: 10-12 years and 13-15 years.Conclusion - CS was a good predictor of aerobic performance (S30min) independent of the chronological age, providing practical information about the aerobic performance state of young swimmers. (C) 2002, Editions scientifiques et medicates, Elsevier SAS. All rights reserved.
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This study investigates whether a 6-wk intermittent hypoxia training (IHT), designed to avoid reductions in training loads and intensities, improves the endurance performance capacity of competitive distance runners. Eighteen athletes were randomly assigned to train in normoxia [Nor group; n = 9; maximal oxygen uptake (VO2 max) = 61.5 +/- 1.1 ml x kg(-1) x min(-1)] or intermittently in hypoxia (Hyp group; n = 9; VO2 max = 64.2 +/- 1.2 ml x kg(-1) x min(-1)). Into their usual normoxic training schedule, athletes included two weekly high-intensity (second ventilatory threshold) and moderate-duration (24-40 min) training sessions, performed either in normoxia [inspired O2 fraction (FiO2) = 20.9%] or in normobaric hypoxia (FiO2) = 14.5%). Before and after training, all athletes realized 1) a normoxic and hypoxic incremental test to determine VO2 max and ventilatory thresholds (first and second ventilatory threshold), and 2) an all-out test at the pretraining minimal velocity eliciting VO2 max to determine their time to exhaustion (T(lim)) and the parameters of O2 uptake (VO2) kinetics. Only the Hyp group significantly improved VO2 max (+5% at both FiO2, P < 0.05), without changes in blood O2-carrying capacity. Moreover, T(lim) lengthened in the Hyp group only (+35%, P < 0.001), without significant modifications of VO2 kinetics. Despite similar training load, the Nor group displayed no such improvements, with unchanged VO2 max (+1%, nonsignificant), T(lim) (+10%, nonsignificant), and VO2 kinetics. In addition, T(lim) improvements in the Hyp group were not correlated with concomitant modifications of other parameters, including VO2 max or VO2 kinetics. The present IHT model, involving specific high-intensity and moderate-duration hypoxic sessions, may potentialize the metabolic stimuli of training in already trained athletes and elicit peripheral muscle adaptations, resulting in increased endurance performance capacity.
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Concerns about the impacts of ocean acidification on marine life have mostly focused on how reduced carbonate saturation affects calcifying organisms. Here, we show that levels of CO2-induced acidification that may be attained by 2100 could also have significant effects on marine organisms by reducing their aerobic capacity. The effects of temperature and acidification on oxygen consumption were tested in 2 species of coral reef fishes, Ostorhinchus doederleini and O. cyanosoma, from the Great Barrier Reef, Australia. The capacity for aerobic activity (aerobic scope) declined at temperatures above the summer average (29°C) and in CO2-acidified water (pH 7.8 and ~1000 ppm CO2) compared to control water (pH 8.15). Aerobic scope declined by 36 and 32% for O. doederleini and O. cyanosoma at temperatures between 29 to 32°C, whereas it declined by 33 and 47% for O. doederleini and O. cyanosoma in acidified water compared to control water. Thus, the declines in aerobic scope in acidified water were similar to those caused by a 3°C increase in water temperature. Minimum aerobic scope values of ~200 mg O2 kg-1 h-1 were attained for both species in acidified water at 32°C, compared with over 600 mg O2 kg-1 h-1 in control water at 29°C. Mortality rate increased sharply at 33°C, indicating that this temperature is close to the lethal thermal limit for both species. Acidification further increased the mortality rate of O. doederleini, but not of O. cyanosoma. These results show that coral reef fishes are sensitive to both higher temperatures and increased levels of dissolved CO2, and that the aerobic performance of some reef fishes could be significantly reduced if climate change continues unabated.
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Women’s handball is a sport, which has seen an accelerated development over the last decade. Data on movement patterns in combination with physiological demands are nearly nonexistent in the literature. The aim of this study was twofold: first, to analyze the horizontal movement pattern, including the sprint acceleration profiles, of individual female elite handball players and the corresponding heart rates (HRs) during a match and secondly to determine underlying correlations with individual aerobic performance. Players from one German First League team (n = 11) and the Norwegian National Team (n = 14) were studied during one match using the Sagit system for movement analysis and Polar HR monitoring for analysis of physiological demands. Mean HR during the match was 86 % of maximum HR (HRmax). With the exception of the goalkeepers (GKs, 78 % of HRmax), no position-specific differences could be detected. Total distance covered during the match was 4614 m (2066 m in GKs and 5251 m in field players (FPs)). Total distance consisted of 9.2 % sprinting, 26.7 % fast running, 28.8 % slow running, and 35.5 % walking. Mean velocity varied between 1.9 km/h (0.52 m/s) (GKs) and 4.2 km/h (1.17 m/s) (FPs, no position effect). Field players with a higher level of maximum oxygen uptake (V̇O2max) executed run activities with a higher velocity but comparable percentage of HRmax as compared to players with lower aerobic performance, independent of FP position. Acceleration profile depended on aerobic performance and the field player’s position. In conclusion, a high V̇O2max appears to be important in top-level international women’s handball. Sprint and endurance training should be conducted according to the specific demands of the player’s position.
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Purpose The aim of this study was to test the effects of sprint interval training (SIT) on cardiorespiratory fitness and aerobic performance measures in young females. Methods Eight healthy, untrained females (age 21 ± 1 years; height 165 ± 5 cm; body mass 63 ± 6 kg) completed cycling peak oxygen uptake ( V˙O2V˙O2 peak), 10-km cycling time trial (TT) and critical power (CP) tests pre- and post-SIT. SIT protocol included 4 × 30-s “all-out” cycling efforts against 7 % body mass interspersed with 4 min of active recovery performed twice per week for 4 weeks (eight sessions in total). Results There was no significant difference in V˙O2V˙O2 peak following SIT compared to the control period (control period: 31.7 ± 3.0 ml kg−1 min−1; post-SIT: 30.9 ± 4.5 ml kg−1 min−1; p > 0.05), but SIT significantly improved time to exhaustion (TTE) (control period: 710 ± 101 s; post-SIT: 798 ± 127 s; p = 0.00), 10-km cycling TT (control period: 1055 ± 129 s; post-SIT: 997 ± 110 s; p = 0.004) and CP (control period: 1.8 ± 0.3 W kg−1; post-SIT: 2.3 ± 0.6 W kg−1; p = 0.01). Conclusions These results demonstrate that young untrained females are responsive to SIT as measured by TTE, 10-km cycling TT and CP tests. However, eight sessions of SIT over 4 weeks are not enough to provide sufficient training stimulus to increase V˙O2V˙O2 peak.
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Research clearly shows that physical activity (PA) is an important factor to develop and maintain good health and adequate body functions in older people. In this context, the purpose of this study was to determine aerobic performance and morphological modifications after a 4 month physical activity program (PAP) in elderly. METHODS Forty subjects divided in two groups (control, n=20; and experimental, n=20) were evaluated twice, at the beginning and after a 4-month-activity program period. This program called “+ age + health” consists of 3 week sessions of one hour each, based on walking and aerobic exercises. The control group had, at its first evaluation, the followings characteristics: average body mass 68kg±15, 28±5 BMI, 37%±5 body fat, 2.2kg±0.4 bone mass, 42%±9 lean body mass and did 129 repetitions ± 46 on a 2-Minute Step Test (2MST). The assessment of anthropometric and morphological variables was measured through an electrical bioimpedance scale (TANITA - BC 545). Aerobic endurance was evaluated from a 2MST.RESULTS In the control group only the percentage of body fat changed significantly, and increased over time. In the experimental group we found a positive relationship between PAP and the majority of morphological variables. The percentage of variation changed in: body fat (-4.3%±7.6, p=0.014), bone mass (2.4%±3.1, p=0.004) and 2MST (33.6%±63.1, p=0.023). In the remaining variables there were no significant modifications. The significant modification in 2MST after the activity period means that the aerobic performance can be improved in elderly, and attenuates the negative effects of age. Moreover, the benefits of PAP can be seen by positive alterations registered in lean body mass and in the percentage of body fat.
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Universidade Estadual de Campinas . Faculdade de Educação Física
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In the evaluation of exercise intolerance of patients with respiratory diseases the American Medical Association (AMA) and the American Thoracic Society (ATS) have proposed similar classifications for rating aerobic impairment using maximum oxygen uptake (VO2max) normalized for total body weight (ml min-1 kg-1). However, subjects with the same VO2max weight-corrected values may have considerably different losses of aerobic performance (VO2max expressed as % predicted). We have proposed a new, specific method for rating loss of aerobic capacity (VO2max, % predicted) and we have compared the two classifications in a prospective study involving 75 silicotic claimants. Logistic regression analysis showed that the disagreement between rating systems (higher dysfunction by the AMA/ATS classification) was associated with age >50 years (P<0.005) and overweight (P = 0.04). Interestingly, clinical (dyspnea score) and spirometric (FEV1) normality were only associated with the VO2max, % predicted, normal values (P<0.01); therefore, in older and obese subjects the AMA/ATS classification tended to overestimate the aerobic dysfunction. We conclude that in the evaluation of aerobic impairment in patients with respiratory diseases, the loss of aerobic capacity (VO2max, % predicted) should be used instead of the traditional method (remaining aerobic ability, VO2max, in ml min-1 kg-1).
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O principal objetivo deste estudo foi verificar o efeito do nível de performance aeróbia na relação entre os índices técnicos correspondentes à velocidade crítica (VC) e à velocidade máxima de 30 minutos (V30) em nadadores. Participaram deste estudo, 23 nadadores do gênero masculino com características antropométricas similares, divididos segundo o nível de performance aeróbia em grupo G1 (maior performance) (n = 13) e G2 (menor performance) (n = 10). Os indivíduos tinham pelo menos quatro anos de experiência no esporte e treinavam um volume semanal de 30.000 a 45.000m. A VC foi determinada através do coeficiente angular da regressão linear entre as distâncias (200 e 400m) e seus respectivos tempos. A V30 foi determinada através da máxima distância realizada em um teste de 30 minutos. Todas as variáveis foram determinadas no nado crawl. A VC foi significantemente maior do que a V30 no grupo G1 (1,30 ± 0,04 vs. 1,23 ± 0,06m.s-1) e no G2 (1,17 ± 0,08 vs. 1,07 ± 0,06m.s-1). As duas variáveis foram maiores no grupo G1. As taxas de braçada correspondentes à VC (TBVC) e à V30 (TBV30) obtidas nos grupos G1 (33,07 ± 4,34 vs. 31,38 ± 4,15 ciclos.min-1) e G2 (35,57 ± 6,52 vs. 33,54 ± 5,89 ciclos.min-1) foram similares entre si. A TBVC foi significantemente menor no grupo 1 do que no grupo 2, enquanto que a TBV30 não foi diferente entre os grupos. Os comprimentos de braçada correspondentes à VC (CBVC) e à V30 (CBV30) foram significantemente maiores no grupo G1 (2,41 ± 0,33 vs. 2,38 ± 0,30m.ciclo-1) do que no G2 (2,04 ± 0,43 vs. 1,97 ± 0,40m.ciclo-1), e similares entre si nos dois grupos. As correlações (r) entre a VC e a V30 e as variáveis técnicas correspondentes às duas velocidades foram significantes em todas as comparações (0,68 a 0,91). Portanto, a relação entre a velocidade e as variáveis técnicas correspondentes à VC e à V30 não é modificada pelo nível de performance aeróbia.
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O objetivo deste estudo foi analisar a validade do consumo máximo de oxigênio (VO2max), da velocidade correspondente ao VO2max (vVO2max), do tempo de exaustão na vVO2max (Tlim), da economia de corrida (EC) e do limiar anaeróbio (LAn) para a predição da performance de atletas de endurance. Quatorze corredores de endurance (33,4 ± 4,4 anos; 62,7 ± 4,3kg; 166,1 ± 5,0cm; VO2max = 60,4 ± 5,9ml.kg-1.min-1) realizaram os seguintes testes: a) competição simulada nas distâncias de 1.500 e 5.000m. e; b) testes de laboratório para a determinação do VO2max, vVO2max, EC, LAn e Tlim na intensidades de 100% vVO2max. As velocidades (km/h) da vVO2max (18,7 ± 0,8), LAn (17,3 ± 1,1) v1.500m (19,9 ± 0,8) e v5.000m (17,9 ± 0,9) foram significantemente diferentes. A regressão múltipla stepwise revelou que o LAn foi o único preditor da performance da v5.000m, explicando 50% da variação desta performance. Para a v1.500m, o Tlim e a vVO2max explicaram 88% da variação da performance. Com base em nossos resultados, pode-se concluir que a validade dos índices fisiológicos (VO2max, vVO2max, Tlim, EC e LAn), para a predição da performance aeróbia de atletas de endurance, é dependente da distância da prova (1.500 x 5.000m) analisada.
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O objetivo do presente estudo foi verificar a utilização da velocidade de 30 minutos (VT-30), freqüência de braçada (fB), comprimento de braçada (CB) e índice de braçada (IB), obtidos no teste T-30, como métodos não-invasivos para determinação da performance aeróbia e técnica de nadadores treinados. Catorze nadadores submeteram-se a três esforços de 400m (85, 90 e 100% do esforço máximo) para determinação da velocidade de limiar anaeróbio (VLan) correspondente à concentração fixa de 3,5mM de lactato e um esforço máximo de 30 minutos (VT-30). fB, CB e IB foram calculados nos 10m centrais da piscina (nado limpo) para o teste T-30 (fBT-30, CBT-30 e IBT-30) e progressivo. Através da relação entre VLan e parâmetros de braçada no teste progressivo, determinaram-se freqüência de braçada de limiar (fBLan), comprimento de braçada de limiar (CBLan) e índice de braçada de limiar (IBLan). O tempo para realizar 400m em máximo esforço foi considerado como parâmetro de performance (P400). Não foi encontrada diferença significativa entre VLan (1,29 ± 0,07m.s-1) e VT-30 (1,29 ± 0,08m.s-1), que ainda apresentaram alta correlação (r = 0,90). Os valores de fBLan (33,6 ± 4,14 ciclos/min) e fBT-30 (34,9 ± 3,53 ciclos/min) e de CBLan (2,09 ± 0,20m/ciclo) e CBT-30 (2,09 ± 0,20m/ciclo) também não foram significativamente diferentes. Correlações significativas (p < 0,05) também foram encontradas entre VT-30 e P400 (r = 0,95); fBLan e fBT-30 (r = 0,73); CBLan e CBT-30 (r = 0,89) e IBLan e IBT-30 (r = 0,94). Conclui-se que a VT30 se mostrou confiável para o monitoramento do treinamento, predição da performance e determinação de parâmetros relacionados à técnica de nadadores.
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This study was undertaken to characterize the effects of monotonous training at lactate minimum (LM) intensity on aerobic and anaerobic performances; glycogen concentrationsin the soleus muscle, the gastrocnemius muscle and the liver; and creatine kinase (CK), free fatty acids and glucose concentrations in rats. The rats were separated into trained (n =10), baseline (n = 10) and sedentary (n=10) groups. The trained group was submitted to the following: 60 min/day, 6 day/week and intensity equivalent to LM during the 12-week training period. The training volume was reduced after four weeks according to a sigmoid function. The total CK (U/L) increased in the trained group after 12 weeks (742.0±158.5) in comparison with the baseline (319.6±40.2) and the sedentary (261.6+42.2) groups. Free fatty acids and glycogen stores (liver, soleus muscle and gastrocnemius muscle) increased after 12 weeks of monotonous training but aerobic and anaerobic performances were unchanged in relation to the sedentary group. The monotonous training at LM increased the level of energy substrates, unchanged aerobic performance, reduced anaerobic capacity and increased the serum CK concentration; however, the rats did not achieve the predicted training volume.