排序方式： 共有41条查询结果，搜索用时 15 毫秒
21.
血乳酸值与肌细胞酸性化关联因素对游泳无氧能力的影响 总被引：5，自引：0，他引：5
狄建 《西安体育学院学报》2002,19(1):46-48
游泳比赛及高强度计时训练时 ,人体骨骼肌大量生成并堆积乳酸导致肌纤维细胞pH值酸性化 ,使运动员陷入力竭性疲劳。这种由剧烈运动而造成的疲劳的性质是因为在缺氧条件下 ,骨骼肌细胞中由于乳酸分解所产生的H+升高而促成人体内环境电解质平衡的pH值下降的原因 ,正是由于人体内环境的H+水平的升高与pH值下降 ,才是导致力竭性疲劳的主要根源。本文尝试对影响血乳酸值的部分因素作一探讨 ,以期对游泳运动员无氧能力影响作用因素的评价方法有进一步认识。 相似文献
22.
我国传统养生学理论极为重视“静”的养生、健身价值。然而,受西方竞技体育思想影响,我国长期以来,以竞技体育作为健身运动的方式,强调更高、更快、更强的运动理念。时至今日,这种运动理念已经越来越不适应当前健康体育和全民健身运动发展的要求。本文以我国传统养生学中“静养观”、“动静平衡理论”为基本出发点,从现代医学理论和研究角度,阐述了健身运动中“静”与“动”的辨正关系,以及“动静平衡”对人体健康的积极意义,揭示盲目强调运动负荷的竞技运动对人体健康的负面作用。对当前的运动健身活动提出了针对性的建议。 相似文献
23.
24.
试论外源性抗氧化剂对运动自由基代谢的影响 总被引：5，自引：0，他引：5
大量研究证明，生物机体各组织、器官、系统不论在安静状态下，还是在运动中，均会产生不同程度的自由基．正常情况下，由于生物机体自身体内存有内源性抗氧化系统，因此，自由基的产生与清除处于一个动态平衡中。但有时因为运动强度增大和运动时间延长或因某些疾病。这种动态平衡就会被破坏。此时自由基造成对机体的损害，结果导致机体免疫功能下降，运动性疲劳和损伤发生。为有效避免自由基损害的发生，国内外已有的研究表明，可以适量补充外源性抗氧化刺来减轻自由基对生物机体的损害程度．本文拟对补充外源性抗氧化剂对自由基代谢的影响作一论述． 相似文献
25.
目的:探讨急性力竭运动及恢复期过程中肾脏TXA2/PGI2代谢平衡调节的生物学效应及自由基代谢的介导作用。方法:SD大鼠随机分为安静对照组、运动后即刻组、运动后1 h组、3 h组和24 h组,各运动组采用递增负荷跑台运动至力竭方案,测定肾组织中TXB2、6-keto-F1α和MDA含量和SOD活性。结果:运动后即刻肾脏TXB2含量和TXB2/6-keto-F1α比值均显著下降,恢复期TXB2含量和TXB2/6-keto-F1α比值均显著低于安静水平。运动及恢复期肾组织SOD活性、MDA含量与TXB2、6-keto-F1α含量均呈显著负相关。结论:力竭运动及恢复期肾脏TXA2/PGI2平衡均下调,运动中有利于维持肾脏局部基本的血液供应,可能与运动性肾脏缺血激发局部代偿机制有关,恢复期则促进肾脏血液再灌注和恢复血供。肾脏抗自由基能力提高可能主要通过抑制肾脏TXA2合成下调TXA2/PGI2平衡。 相似文献
26.
《Research quarterly for exercise and sport》2012,83(4):629-640
ABSTRACTPurpose: To compare children’s energy expenditure (EE) levels during object projection skill performance (OPSP; e.g., kicking, throwing, striking) as assessed by hip- and wrist-worn accelerometers. Method: Forty-two children (female n = 20, Mage = 8.1 ± 0.8 years) performed three, nine-minute sessions of kicking, over-arm throwing, and striking at performance intervals of 6, 12, and 30 seconds. EE was estimated using indirect calorimetry (COSMED k4b2) and accelerometers (ActiGraph GT3X+) worn on three different locations (hip, dominant-wrist, and non-dominant-wrist) using four commonly used cut-points. Bland-Altman plots were used to analyze the agreement in EE estimations between accelerometry and indirect calorimetry (METS). Chi-square goodness of fit tests were used to examine the agreement between accelerometry and indirect calorimetry. Results: Hip- and wrist-worn accelerometers underestimated EE, compared to indirect calorimetry, during all performance conditions. Skill practice at a rate of two trials per minute resulted in the equivalent of moderate PA and five trials per minute resulted in vigorous PA (as measured by indirect calorimetry), yet was only categorized as light and/or moderate activity by all measured forms of accelerometry. Conclusion: This is one of the first studies to evaluate the ability of hip- and wrist-worn accelerometers to predict PA intensity levels during OPSP in children. These data may significantly impact PA intervention measurement strategies by revealing the lack of validity in accelerometers to accurately predict PA levels during OPSP in children. 相似文献
27.
研究评价6周游泳运动对载脂蛋白E（apoE-／-）敲除的6周龄大鼠脂质代谢和动脉粥样硬化的影响。大鼠分为对照组（n=7）和运动组（n=7）。运动组大鼠进行6周递增负荷游泳运动,每周均按照第一天10分钟,每周5天（每天增加10分钟,直到连续运动1小时）。评价运动前和运动后血浆总胆固醇。处死大鼠后评价胸、腹主动脉粥样硬化的面积。体重、脂代谢两组结果相似。运动组的相关统计指数降低,表明apoE-/-大鼠游泳运动后动脉粥样硬化病变减少。但这种改变与脂肪代谢无关。 相似文献
28.
Ricardo Berton Miguel S Conceição Cleiton A Libardi Rafael R Canevarolo Arthur F Gáspari Mara Patrícia T Chacon-Mikahil 《Journal of sports sciences》2017,35(12):1211-1218
This study analysed the time course of the global metabolic acute response after resistance exercise (RE), with the use of proton nuclear magnetic resonance (1H NMR) spectroscopy. Ten young healthy males performed 4 sets of 10 repetitions at 70% of one-repetition maximum in the leg press and knee extension exercises and had the serum metabolome assessed at 5, 15, 30 and 60 min post-RE. Measurements were also performed 1 h earlier and immediately before the exercises, as an attempt to characterise each participant’s serum metabolome at rest. One-way ANOVA was applied and the significance level was set at P ≤ 0.05. RE promoted an increase in 2-hydroxybutyrate, 2-oxoisocaproate, 3-hydroxyisobutyrate, alanine, hypoxanthine, lactate, pyruvate and succinate concentrations. However, isoleucine, leucine, lysine, ornithine and valine had their concentrations decreased post-RE compared with at rest. This is the first study to show significant changes in serum concentration of metabolites such as 2-oxoisocaproate, 2-hydroxybutyrate, 3-hydroxyisobutyrate, lysine, hypoxanthine and pyruvate post-RE, attesting metabolomics as an interesting approach to advance in the understanding of global RE-induced metabolic changes. Moreover, the present data could influence the time point of blood collection in the future studies that aims to investigate metabolism and exercise. 相似文献
29.
30.
Michael A. Christmass Susan E. Richmond Nigel T. Cable Peter G. Arthur Peter E. Hartmann 《Journal of sports sciences》2013,31(8):739-747
The aim of this study was to determine exercise intensity and metabolic response during singles tennis play. Techniques for assessment of exercise intensity were studied on-court and in the laboratory. The on-court study required eight State-level tennis players to complete a competitive singles tennis match. During the laboratory study, a separate group of seven male subjects performed an intermittent and a continuous treadmill run. During tennis play, heart rate (HR) and relative exercise intensity (72 ± 1.9% V O 2m ax ; estimated from measurement of heart rate) remained constant (83.4 ± 0.9% HR m ax ; mean s x ) after the second change of end. The peak value for estimated play intensity (1.25 ± 0.11 steps . s -1 ; from video analysis) occurred after the fourth change of end (P < 0.005). Plasma lactate concentration, measured at rest and at the change of ends, increased 175% from 2.13 ± 0.32 mmol . l -1 at rest to a peak 5.86 ± 1.33 mmol . l -1 after the sixth change of end (P < 0.001). A linear regression model, which included significant terms for %HR m ax (P < 0.001) and subject (P < 0.001), as well as a %HR max subject interaction (P < 0.05), accounted for 82% of the variation in plasma lactate concentration. During intermittent laboratory treadmill running, % V O 2peak estimated from heart rate was 17% higher than the value derived from the measured V O 2 (79.7 ± 2.2% and 69.0 ± 2.5% V O 2peak respectively; P < 0.001). The % V O 2peak was estimated with reasonable accuracy during continuous treadmill running (5% error). We conclude that changes in exercise intensity based on measurements of heart rate and a time-motion analysis of court movement patterns explain the variation in lactate concentration observed during singles tennis, and that measuring heart rate during play, in association with preliminary fitness tests to estimate V O 2 , will overestimate the aerobic response. (P < 0.001), estimated play intensity 相似文献