运动对脂蛋白(a)的影响

脂蛋白(a)[LP(a)] 在结构上类似低密度脂蛋白(LDL) 。血清中Lp(a) 浓度基本上受遗传决定,但有种族差异。Lp(a) 与心血管疾病之间联系有明显的独立性。冠心病是世界许多发达国家中引起死亡的主要因素,运动是预防冠心病的重要手段之一。因此近年来人们开始注意各种运动训练对Lp(a) 浓度的影响,以期探讨运动防治冠心病之机理。结果表明,长期耐力训练可轻度升高Lp(a) 浓度。初步推测,这种运动可能较有利于运动引起的血管微小创伤的修复,与其他血浆脂蛋白的变化一起对防治冠心病(CHD) 有积极作用。急性大强度运动后,可使受试者血Lp(a)浓度下降,表现出组织损伤之应激反应。     

对研究生运动处方教学模式的探讨

运动处方教学是目前教育界讨论的热点话题，对于高校研究生应该怎样进行体育教学和采取什么样的方式教学，各院校意见不一。运用文献资料法，从运动处方概念和运动处方教学观点出发，结合研究生自身特点，提出在研究生中开展运动处方教学的理念，并设计出了相应的处方教学模式，旨在为研究生体育教学的开展提供理论参考。     

专项功率评价与赛艇水陆训练强度统一的研究

分析了国际上和中国赛艇队对功率评价与赛艇水陆训练强度控制问题的有关研究，对于如何把赛艇陆上测试的功与功率与水上的运动强度统一起来，如何运用功和功率在水陆训练整体评价运动员体能的方法进行了分析；对如何建立起赛艇水陆训练强度测评统一、完整的国家标准和体系进行了探讨。通过水上测试与陆上测功仪的功率数据的合理对应，能准确发现各种技能的细节问题，结合生化指标测试，就可能迅速建立起赛艇水陆训练强度测评统一、完整、先进的国家标准和体系，对2008年奥运会中国体能项目的全面突破和“119工程”的完成有实质的意义。     

Objective and subjective methods for quantifying training load in wheelchair basketball small-sided games

The aim of the present study was to analyse the training load in wheelchair basketball small-sided games and determine the relationship between heart rate (HR)-based training load and perceived exertion (RPE)-based training load methods among small-sided games bouts. HR-based measurements of training load included Edwards’ training load and Stagno’s training impulses (TRIMP_MOD) while RPE-based training load measurements included cardiopulmonary (session RPEres) and muscular (session RPEmus) values. Data were collected from 12 wheelchair basketball players during five consecutive weeks. The total load for the small-sided games sessions was 67.5 ± 6.7 and 55.3 ± 12.5 AU in HR-based training load (Edwards’ training load and TRIMP_MOD), while the RPE-based training loads were 99.3 ± 26.9 (session RPEres) and 100.8 ± 31.2 AU (session RPEmus). Bout-to-bout analysis identified greater session RPEmus in the third [P < 0.05; effect size (ES) = 0.66, moderate] and fourth bouts (P < 0.05; ES = 0.64, moderate) than in the first bout, but other measures did not differ. Mean correlations indicated a trivial and small relationship among HR-based and RPE-based training loads. It is suggested that HR-based and RPE-based training loads provide different information, but these two methods could be complementary because one method could help us to understand the limitations of the other.     

Top-down and bottom-up guidance in comprehension of schematic football diagrams

Comprehension of a narrated diagram entail complex cognitive processing as learner is challenged to extract the orally evoked information. The present experiment examined the effects of 2 different forms of attention guidance – bottom-up and top-down – on comprehension performance, cognitive load investment, and motivation to learn, using a 2 × 2 mixed design with factors “Expertise” (Expert vs. Novice) and “Condition” (no-signal, circle, segment). The results revealed an expertise reversal effect indicating that the incorporation of visual signals in diagram is effective for novice learners but partially reverses and becomes ineffective for more experienced learners (even though they invested less mental effort and reported higher level of motivation in the segmented condition). The findings suggested that the effectiveness of instructional guidance depends heavily on levels of prior knowledge.     

Is there really an eccentric action of the hamstrings during the swing phase of high-speed running? part I: A critical review of the literature

It is widely assumed that there is an eccentric hamstring muscle fibre action during the swing phase of high-speed running. However, animal and modelling studies in humans show that the increasing distance between musculotendinous attachment points during forward swing is primarily due to passive lengthening associated with the take-up of muscle slack. Later in the swing phase, the contractile element (CE) maintains a near isometric action while the series elastic (tendinous) element first stretches as the knee extends, and then recoils causing the swing leg to forcefully retract prior to ground contact. Although modelling studies showed some active lengthening of the contractile (muscular) element during the mid-swing phase of high-speed running, we argue that the increasing distance between the attachment points should not be interpreted as an eccentric action of the CE due to the effects of muscle slack. Therefore, there may actually be no significant eccentric, but rather predominantly an isometric action of the hamstrings CE during the swing phase of high-speed running when the attachment points of the hamstrings are moving apart. Based on this, we propose that isometric rather than eccentric exercises are a more specific way of conditioning the hamstrings for high-speed running.     

Resting Bradycardia,Enhanced Postexercise Heart Rate Recovery and Cardiorespiratory Fitness in Recreational Ballroom Dancers

Purpose: In a cross-sectional study design, we evaluated the resting heart rate (HR_baseline) and exercise and postexercise stress test-related chronotropic responses in male practitioners of recreational ballroom dancing (BD; n = 25, M_age = 26.6 ± 6.1 years) compared to a control group of insufficiently active nondancers (CG; n = 25, M_age = 25.9 ± 4.5 years). Method: All participants underwent a submaximal exercise test. At 85% of the maximal predicted HR, the recovery protocol was started, and heart rate recovery (HRR) was recorded during 1-min intervals for 5 min. Results: Compared with CG, BD showed lower HR_baseline (70 beats per minute [bpm] vs. 62 bpm, respectively, U = 143, p < .05, ES = .46), lower preexercise HR (94 bpm vs. 86 bpm, U = 157, p < .05, ES = .42), longer exercise test duration (346 s vs. 420 s, U = 95.5, p < .05, ES = .59), and higher HRR for 5 min postexercise (U = 1.29–1.89, p < .05, ES = .33–.50) as follows: 1st min (32 bpm vs. 40 bpm), 2nd min (45 bpm vs. 53 bpm), 3rd min (51 bpm vs. 58 bpm), 4th min (55 bpm vs. 59 bpm), and 5th min (59 bpm vs. 63 bpm). The coefficient of HRR from the 1st min to the 5th min postexercise was similar in both groups (U = 229–311, p > .05, ES = < .10–.22). Conclusion: Heightened cardiovascular functional status characterized by favorable enhanced chronotropic dynamics appears to occur in practitioners of recreational ballroom dancing, which suggests that this modality of exercise may result in health benefits.     

Physical Inactivity,Obesity, and Type 2 Diabetes: An Evolutionary Perspective

Physical inactivity (and unhealthy nutrition) has distorted body composition and, in turn, reordered the proportions of myocyte and adipocyte insulin receptors. Insulin acting on adipocyte receptors produces less glucose uptake than does comparable interaction with myocyte receptors. Accordingly, in individuals with disproportionate muscle/fat composition, any given glucose load requires greater-than-normal pancreatic insulin secretion for adequate disposal. This hyperinsulinemia then becomes the leading cause of type 2 diabetes (T2DM) as insulin-sensitive tissues become desensitized. Because T2DM is rooted in potentially reversible lifestyle factors, rather than focusing on the intricacies of glucoregulation at the molecular level and on testing new drugs to control blood sugar, this article calls for a new prevention and treatment paradigm, in which exercise and weight control are essential and for which an inexpensive and acceptably accurate measure of body muscle and fat proportions is needed.     

不同运动方式对更年期女性身心健康的影响

摘要：目的：探讨不同的运动方式干预对更年期女性体内激素水平、自由基代谢和心理健康的影响效应,旨在为改善和提高更年期女性的生活质量提供参考。方法：随机选取符合纳入标准的更年期女性受试者,依据不同运动方式分为4组,即对照组(CG)24人、有氧运动组(AG)27人、抗阻运动组(RG)27人、健身气功组(QG)27人,实施24周的运动干预,在实验前、中、后分别对相关激素和自由基代谢酶水平进行测量和统计分析,并进行更年期症状与心理状态评估。结果：24周后,AG和RG的血清E2、SOD和CAT值增加幅度,FSH、MDA、XOD值以及Kupperman、SAS和SDS评分降低幅度均明显高于QG和CG。结论：24周中等强度的有氧运动和抗阻运动与低强度的健身气功相比,更有助于改善更年期女性体内的雌激素和自由基代谢水平,缓解心理焦虑、抑郁等更年期不适症状。     

Nrf2在有氧运动训练中对小鼠骨骼肌抗氧化能力的作用

摘要：目的：Nrf2是机体氧化还原平衡的主要调节因子,本研究试图探讨Nrf2在有氧运动训练中对小鼠骨骼肌抗氧化能力的作用。方法：8周龄野生C57BL/6J小鼠和Nrf2敲除小鼠40只,雌雄各半。进一步各为安静组和运动组,每组10只,共4组：分别为野生安静组（WC）,野生运动组（WE）,敲除安静组（KC）和敲除运动组（KE）。运动组进行4周运动强度为70%VO2max跑速的跑台运动,每周运动6 d,每天运动1 h。运动组最后一次运动后休息48 h脱颈处死,取小鼠后腿骨骼肌。RT-PCR测量Nrf2及Nrf2介导的抗氧化基因mRNA表达量;Western blot法测定骨骼肌Nrf2及抗氧化蛋白含量; GSH试剂盒测量GSH/GSSG比值。结果：1）在安静情况下,KC组和WC组相比,骨骼肌中GSR、NQO1、GCLc、GPX、HO-1和SOD2这6个抗氧化蛋白表达以及GSH/GSSG值没有显著性改变。 2）4周有氧运动训练之后,Nrf2敲除运动组的大部分抗氧化蛋白（CAT, NQO1-1, GCLc, HO-1 and SOD2）和GSH/GSSG值都要显著低于野生运动组。结论：4周70%VO2max强度的有氧运动训练,增加了成年Nrf2敲除和野生鼠骨骼肌抗氧化蛋白表达量和GSH/GSSG比值的差异,而在无训练安静情况下在两种鼠中这些指标的差异不大。说明Nrf2对有氧运动训练中骨骼肌的抗氧化反应起着非常重要的作用。