共查询到20条相似文献，搜索用时 78 毫秒
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本文以菜农为对象,在实验室用极限下不同负荷连续工作测试了心率、耗氧率和肺通气量,以所获数据建立了负荷与心率、耗氧率及肺通气量的多元回归方程。同时,为便于现场调查应用,还建立了上述指标相互间的单元回归方程。 相似文献
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以连续递增负荷的踏车运动，测定了34名少年速度滑冰运动员在不同工作负荷时的通气量、吸氧量、心率、最大吸氧量、无氧阈、氧脉搏曲线和呼吸当量曲线，确定了最大氧脉搏和最佳呼吸效率点及生理参数。探讨了最大氧脉搏、无氧阈、最佳呼吸效率点在运动训练中的作用。为少年速滑运动员的训练工作提供科学依据。 相似文献
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测定了篮球、中长跑、短跑、武术套路运动员在递增负荷运动中氧通气当量的变化曲线,并确定了最佳呼吸效率点.结果发现,不同专项运动员的氧通气当量有相似的变化规律,随着运动强度的增加,运动时间的延长,氧通气当量先略下降,在运动负荷达到150W时降低到一个最低值即最佳呼吸效率点,然后逐渐上升.结果提示,氧通气当量和最佳呼吸效率点可作为无氧阈深入研究的一种辅助手段,最佳呼吸效率点时的强度亦可作为有氧训练的界限强度. 相似文献
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目的:利用便携式肺功能仪,在场地条件下测试中跑运动员4种次极限跑速时的跑步经济性(RE),比较以时间耗氧(ml/kg/min)、距离耗氧(ml/kg/km)和距离耗能(kcal/kg/km)单位评价RE的有效性。方法:10名中跑运动员在标准田径场跑道上完成1次递增负荷测试和1次持续4个回合的恒定负荷测试。通过递增负荷测试获取最大耗氧量(VO2max)和无氧阈(AT),并分别以70%、80%、90%、105%AT强度完成5～10min恒定负荷测试,取稳态耗氧量及相关呼吸指标计算3种不同单位表示时的RE。结果:3种单位表示的RE在两两间均呈现出非常显著的相关关系(P<0.01)。随运动强度的增高,单位时间的耗氧在每级间均显著增高(P<0.05);单位距离的耗氧则无明显变化(P>0.05),且在80%～105%AT强度间出现微弱的降低;单位距离的能耗在70%～90%AT间缓慢增高(P>0.05),但在90%～105%AT间增高显著(P<0.05);呼吸交换率(RER)则在80%～105%AT间出现了不同程度地显著提高(80%～90%AT:P<0.05,90%～105%AT:P<0.01)。结论:无论是时间耗氧单位还是距离耗氧单位,都忽略了底物利用的不同对耗氧量的影响,无法有效评定RE。能量单位更符合RE的本质特征,与运动实践更加相关,是评定RE的有效单位。 相似文献
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目的:以不同方式的摄氧取值以及不同强度的测试次数建立相应的速度-摄氧预测方程,比较各方程所得最大累积氧亏的差异,对最大累积氧亏的测试方案进行简化设计并对其有效性进行论证.方法:15名男子1 500m跑运动员在标准田径跑道上分别完成1次递增负荷测试、1次1 500 m跑测试及2次持续各5回合、每回合10 min的恒定负荷测试.以10回合恒定负荷测试中8～10 min的摄氧取值建立的预测方程为标准,比较4～6 min、6～8min固定时段的摄氧取值以及遥测稳态摄氧取值对建立预测方程的影响,并比较减少不同次数的高负荷、中等负荷以及低负荷测试对建立预测方程的影响.结果:遥测稳态摄氧的判定时间在4 min 12 s～8 min 46 s之间,以遥测稳态摄氧建立方程所计算的需氧量和最大累积氧亏与标准值无明显差异(P＞0.0167);减少中间负荷测试的次数≦3时,对速度-摄氧方程的预测效果无显著影响(P＞0.0167);以安静站立时的摄氧量作为预测方程的截距,并减少最低两级负荷以及中间两级负荷测试构建预测方程,其所得的最大累积氧亏与标准值间的一致性边界为-2.22～4.77 ml O2/kg,仅有6.7％的值处于一致性边界之外;简化方程所得最大累积氧亏的时间相对值(ml O/kg/s)与1 500m跑的成绩有显著的相关性(r=-0.561,P＜0.05).结论:设定安静站立时的摄氧量为截距,减少4次负荷分别为70％～80％及100％～105％无氧阈强度的恒定负荷测试,以遥测稳态摄氧取值构建预测方程,可在保证最大累积氧亏计算准确性的前提下,大幅节省测试耗时. 相似文献
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目的通过比较模拟HiLo与常氧训练对照组的网织红细胞及其参数指标,探讨不同强度模拟HiLo对骨髓造血功能的影响。方法将SD大鼠随机分成16小组,模拟高住低练组与常氧组各8组且一一对应。5周低强度训练、6周高强度训练结束后,检测大鼠的网织红细胞及其分类指标,并对数据进行统计学处理。结果模拟HiLo的高强度定量负荷组与极限负荷组的Retic%显著低于常氧组(P<0.01)。两氧环境中,高强度定量负荷组Retic%显著低于运动后40h安静组,极限负荷组较高强度定量负荷组有所升高,但无显著性差异。结论高、低强度的模拟HiLo对骨髓造血功能产生不同程度的影响,高强度、极限强度训练骨髓造血功能相对常氧受到显著抑制;在两氧环境下,高强度运动后即刻骨髓增殖活性受抑,而极限强度运动可在一定程度上刺激骨髓造血,休息40h后,模拟HiLo出现代偿性恢复。 相似文献
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本文对于高等数学中的求极限的题型,将其难度系数进行了综合打分;通过对难度系数的分析,说明了在考研高等数学中极限部分常考的题型,便于考生复习时能够抓住重点,对于考研的同学有一定的指导作用。 相似文献
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极限概念是微积分中至关重要的概念,微积分中大量的基本概念都是用极限概念来表达的,例如连续、导数、定积分、级数、重积分、曲线积分及曲面积分的概念等等,因此,极限概念的教学是一个值得研究的内容. 相似文献
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In 19 elite schoolboy rowers, the relationships between anthropometric characteristics, metabolic parameters, strength variables and 2000-m rowing ergometer performance time were analysed to test the hypothesis that a combination of these variables would predict performance better than either individual variables or one category of variables. Anthropometric characteristics, maximal oxygen uptake (V O 2m ax ), accumulated oxygen deficit, net efficiency, leg strength and 2000-m rowing ergometer time were measured. Body mass, V O 2max and knee extension correlated with 2000-m performance time (r = -0.41, -0.43 and-0.40, respectively; P 0.05), while net efficiency and accumulated oxygen deficit did not. Multiple-regression analyses indicated that the prediction model using anthropometric variables alone best predicts performance (R = 0.82), followed by the equation comprising body mass, V O 2max and skinfolds (R = 0.80). Although the regression equations increased the predictive power from that obtained using single variables, the hypothesis that a prediction model consisting of variables from different physiological categories would predict performance better than variables from one physiological category was not supported. 相似文献
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网球运动主要是以短时间的高强度的对抗为主,间杂着一些短时间的休息调整,涉及很多肌肉群,几乎没有任何其他运动与其相似。针对这项具有特殊生理特性的运动,如何建立其能量系统的专门训练,是十分复杂的,而且是十分重要的。 相似文献
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DAVID W. HILL 《Journal of sports sciences》2013,31(6):477-483
The aim of this study was to estimate the energy contributions in middle-distance running events for male and female university athletes. The oxygen uptake (VO2) response during high-speed running was measured directly during exhaustive treadmill tests. Muscle mass was estimated using anthropometry. Each athlete completed an average of three races over 400 m, 800 m or 1500 m. Five minutes after each race, they provided a blood sample for determination of blood lactate concentration. For each race, energy cost, which was expressed as oxygen equivalents, was calculated as the sum of the aerobic and anaerobic components. The aerobic contribution was calculated as the sum of oxygen stores (2.3 ml O2.kg body mass-1) and total VO2 (based on the VO2 response to treadmill running). The anaerobic contribution was calculated as the sum of the energy available from phosphocreatine stores (37 ml O2.kg muscle mass-1) and the energy from glycolysis (3.0 ml O2.kg body mass-1 per mmol.l-1 increase in blood lactate concentration). For the women, the anaerobic energy contributions for the 400 m, 800 m and 1500 m averaged 62% 33% and 17% respectively. For the men, the anaerobic contributions averaged 63%39% and 20%respectively. This information will help coaches and sport scientists to design and implement individualized training programmes. 相似文献
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解偶联蛋白3是线粒体内膜上的一种转运蛋白,研究证实解偶联蛋白3与线粒体能量代谢、线粒体活性氧生成及脂肪代谢等有关。就解偶联蛋白3的结构、分布、表达调控及其介导的线粒体活性氧生成等相关问题作一综述。 相似文献
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中国普通大学生的VO2max测定及其影响因素 总被引：3，自引：0，他引：3
采用文献资料法,对我国普通大学生有氧工作能力的研究成果进行综述,重点阐明了评价有氧工作能力的重要指标--最大摄氧量的正常值和测定方法.还讨论了中国普通大学生最大摄氧量的影响因素,为更好地提高大学生的有氧工作能力提供理论依据. 相似文献
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Research in paediatric exercise metabolism has been constrained by being unable to interrogate muscle in vivo. Conventionally, research has been limited to the estimation of muscle metabolism from observations of blood and respiratory gases during maximal or steady state exercise and the analysis of a few muscle biopsies taken at rest or post-exercise. The purpose of this paper is to review how the introduction of 31P-magnetic resonance spectroscopy and breath-by-breath oxygen uptake kinetics studies has contributed to current understanding of exercise metabolism during growth and maturation. Methodologically robust studies using 31P-magnetic resonance spectroscopy and oxygen uptake kinetics with children are sparse and some data are in conflict. However, it can be concluded that children respond to exercise with enhanced oxygen utilization within the myocyte compared with adults and that their responses are consistent with a greater recruitment of type I muscle fibres. Changes in muscle metabolism are age, maturation- and sex-related and dependent on the intensity of the exercise challenge. The introduction of experimental models such as “priming exercise” and “work-to-work” transitions provide intriguing avenues of research into the mechanisms underpinning exercise metabolism during growth and maturation. 相似文献
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注氧加干扰电治疗腰背痛疗效观察 总被引：1，自引：0，他引：1
腰背痛是骨伤科运动损伤常见病、多发病,文章从软组织损害的角度对其发病机理,解剖特点进行探讨。以纯氧注入骶棘肌筋膜下,强手法推、挤、擦、局部痛点指压,加上干扰电流在人体内交叉干扰处形成干扰场,具有低、中频两种电流的特性作用于局部,使粘连的肌肉筋膜,松解、拔离。从临床观察注氧加干扰电、指压、综合疗法,临床治愈率明显提高,疗程相应缩短,是治疗本病有效的手段之一。 相似文献
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A comparison of the physiological response to simulated altitude exposure and r-HuEpo administration
Michael J. Ashenden Allan G. Hahn David T. Martin Peter Logan Robin Parisotto Christopher J. Gore 《Journal of sports sciences》2013,31(11):831-837
Concerns have been raised about the morality of using simulated altitude facilities in an attempt to improve athletic performance. One assumption that has been influential in this debate is the belief that altitude houses simply mimic the physiological effects of illegal recombinant human erythropoietin (r-HuEpo) doping. To test the validity of this assumption, the haematological and physiological responses of 23 well-trained athletes exposed to a simulated altitude of 2650-3000 m for 11-23 nights were contrasted with those of healthy volunteers receiving a low dose (150 IU·kg-1 per week) of r-HuEpo for 25 days. Serial blood samples were analysed for serum erythropoietin and percent reticulocytes; maximal oxygen uptake ([Vdot]O2max) was assessed before and after r-HuEpo administration or simulated altitude exposure. The group mean increase in serum erythropoietin (422% for r-HuEpo vs 59% for simulated altitude), percent reticulocytes (89% vs 30%) and [Vdot]O2max (6.6% vs -2.0%) indicated that simulated altitude did not induce the changes obtained with r-HuEpo administration. Based on the disparity of these responses, we conclude that simulated altitude facilities should not be considered unethical based solely on the tenet that they provide an alternative means of obtaining the benefits sought by illegal r-HuEpo doping. 相似文献
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Joseph L. Andreacci Linda M. Lemura Steven L. Cohen Ethan A. Urbansky Sara A. Chelland Serge P. von Duvillard 《Journal of sports sciences》2013,31(4):345-352
The aim of this study was to determine the effects of frequency of verbal encouragement during maximal exercise testing. Twenty-eight participants (12 males, 16 females) aged 20.9 - 1.5 years (mean - s ) performed a maximal exercise test ( V O 2max ) on a treadmill without any verbal encouragement. The participants were matched according to their pre-test V O 2max and placed into either a control group or one of three experimental groups. They performed a second exercise test (post-test) 1 week later. During the second test, the control group received no verbal encouragement; the 20 s (20E), 60 s (60E) and 180 s (180E) encouragement groups received verbal encouragement every 20, 60 and 180 s, respectively, beginning with stage 3 of the exercise test. Relative V O 2max , exercise time, blood lactate concentration, respiratory exchange ratio (RER) and ratings of perceived exertion (RPE) were not significantly different from the first test to the second test for the control group without verbal encouragement and the 180E group that received infrequent encouragement. Post-test values were significantly higher than pre-test values for the 20E and 60E groups. The post-test values of the 20E group were significantly higher than their pre-test values for relative V O 2max ( P ? 0.001), exercise time ( P ? 0.0001), blood lactate concentr . ation ( P ? 0.05), RER ( P ? 0.01) and RPE ( P ? 0.0001); this was also the case for the 60E group for relative V O 2max ( P ? 0.01), blood lactate concentration ( P ? 0.05), RER ( P ? 0.05) and RPE ( P ? 0.05). The results suggest that frequent verbal encouragement (every 20 s and 60 s in the present study) leads to significantly greater maximum effort in a treadmill test than when no encouragement is given or when the encouragement is infrequent (i.e. every 180 s). 相似文献