运动与骨骼肌Na+-K+-ATP酶

本文简要介绍了骨骼肌Na -K -ATP酶的分布和功能;概述了近年来急性运动、运动训练和低氧环境下运动与骨骼肌Na -K -ATP酶及其mRNA表达的研究概况;分析了运动中影响骨骼肌Na -K ATP酶的因素.     

Na^＋，K^＋-ATP酶与运动和人体健康

Na ,K -ATP酶利用ATP储存的能量来保证Na 、K 离子在膜内外的穿梭,而离子在膜内外的这种穿梭运动是启动神经信号传导和其它生命过程的基本步骤。综述了Na ,K -ATP酶的结构和功能特点、Na ,K -ATP酶与人体健康和运动的关系,并归纳了不同运动形式和强度等因素与Na ,K -ATP酶关系的研究进展,分析了现有研究手段的利弊及研究特点。     

有氧训练对红细胞自由基代谢和Na^＋-K^＋-ATP酶活性影响

探讨不同时间负荷训练大鼠红细胞自由基代谢和Na -K -ATP酶活性。结果表明急性运动时红细胞产生氧化应激,而有氧训练使红细胞自由基代谢得以改善。运动训练改善红细胞自由基代谢和Na -K -ATP酶活性和每日训练持续时间有一定的关系,在一定程度上红细胞自由基代谢水平影响着红细胞膜功能蛋白活性。     

短道速滑运动员Na＋，K＋-ATP酶活性变化特征

Na＋,K＋-ATP酶活性对训练负荷具有较高的敏感性,利用Na＋,K＋-ATP酶活性衡量训练效果。评定不同训练方法对提高短道速滑运动员能力的效能,对促进短道速滑项目科学化训练具有重要价值。通过对省、市队短道速滑和未经训练受试对象采用间歇训练法和持续训练法运动4周后观察Na＋,K＋-ATP酶活性变化,研究结果表明：经过短道速滑训练的受试对象Na＋,K＋-ATP酶活性要高于非训练组,并且训练年限越长,Na＋,K＋-ATP酶活性就越高;采用间歇训练法要比持续训练法更容易提升Na＋,K＋-ATP酶活性;动作协调性好的短道速滑运动员Na＋,K＋-ATP酶活性高于协调性差的短道速滑运动员。实验提示：Na＋,K＋-ATP酶活性也可作为短道速滑运动员评定训练负荷和衡量训练效果的敏感指标,短道速滑运动员采用间歇性训练法的训练效果要好于持续性训练法。     

不同训练方法对大鼠肾脏组织Na~+,K~+-ATP酶活性及自由基代谢的影响

对大强度间歇训练和持续训练大鼠肾脏组织Na ,K -ATP酶活性及自由基进行比较,结果显示:(1)6周训练后,两训练组在安静状态下,大鼠肾脏组织中Na ,K -ATP酶活性略为升高,MDA含量显著下降,SOD酶活性略有下降,SOD/MDA显著升高;(2)两训练组运动后即刻与对照组相比,Na ,K -ATP酶活性略有下降,SOD和MDA显著下降;(3)两训练组之间各指标均无显著差异。间歇训练和持续训练均能降低肾脏组织脂质过氧化水平,使Na ,K -ATP酶免遭氧化损伤。     

大负荷运动对大鼠心肌细胞膜钠钾泵、钙泵与肌浆网钙泵活性的影响

目的:探讨大负荷跑台运动对心肌细胞膜Na+-K+-ATPase、Ca2+-ATPase与肌浆网Ca2+-ATPase活性的影响及其与超微结构变化的关系.方法:成年雄性SD大鼠24只,随机分为空白对照组(A组)、运动后即刻组(B组)与运动后24 h组(C组).定磷法测定各组大鼠心室肌细胞膜Na+-K+-ATPase、Ca2+-ATPase活性与肌浆网Ca2+-ATPase活性;电镜观察各组大鼠左室前壁心肌细胞超微结构变化.结果:B组心肌细胞膜Na+-K+-ATPase、Ca2+-ATPase活性显著低于其他两组,C组肌浆网Ca2+-ATPase活性显著低于其他两组;B组线粒体结构明显损伤,C组肌原纤维结构明显损伤、肌细胞及肌浆网肿胀.结论:大负荷运动引起大鼠心肌细胞膜Na+-K+-ATPase、Ca2+-ATPase与肌浆网Ca2+-ATPase活性降低及心肌超微结构异常,但变化不完全同步;细胞膜Na+-K+-ATPase、Ca2+-ATPas活性下降可能与线粒体大面积损伤有关.     

统治全场的指挥官

本场比赛是Na’Vi×BOCT的一场路人局,这位大神一向以“大嘴巴”闻名于DOTA2界,作为Na’Vi的核心成员之一,其实力是不容小觑的。不过在本场比赛中×BOCT前期就出现了很多搞笑的失误,还好后期的稳定发挥让其挽回了“面子”。     

Na＇Vi巧设陷阱破解iG“完美阵容”

如果说本届评选本届T12上最具传奇色彩的一场比赛,邢无疑就是胜者组半决赛Na’Vi同iG的第二局较量。之所以说这是一场传奇性的比赛,是因为iG在本场中拿到了一套被誉为无法破解的完美阵容,而Na’Vi却轻松的击垮了iG。而当我们回顾整场比赛时,却发现这一切都是Na’Vi设好的一个陷阱,而从BP阶段开始,iG就已经越陷越深,最后的溃败也就不可避免了。     

力竭游泳运动对肠组织MDA、Free-SH、ATP含量、Na+-K+-ATPase和Ca2+-ATPase活性的影响

探讨力竭性运动引起的氧化应激对肠功能的影响及运动性肠功能紊乱的原因,32只SD雄性大鼠随机分为4组:即对照组(C);运动后即刻组EX;运动后30min组(EX30);运动后60min组(EX60),测定力竭性游泳后不同时相肠组织匀浆MDA、游离巯基和ATP含量。结果:运动后肠组织MDA含量在运动后30min、60min显著性增加(P<0.01);运动后Free-SH含量在运动后30min(P<0.05)和运动后60min后(P<0.01)显著下降;运动后30min组ATP含量显著下降(P<0.01);运动后30min,Ca2+-ATPase活性下降(P<0.05);运动后60min,Na+-K+-AT-Pase和Ca2+-ATPase活性均显著下降(P<0.05)。结论:运动源性自由基产生增加,使肠组织中游离巯基被氧化,导致ATP含量下降,Na+-K+-ATPase和Ca2+-ATPase活性下降,可能是造成运动性肠功能紊乱的重要因素之一。     

神装小小的逆袭

本场比赛是Na’Vi和Liquid在TI4小组赛中的一场比赛,相信大家肯定知晓Na’Vi战队,在前三届TI的赛事中,其取得了两次第二,一次冠军的好成绩,队里有Solo悍将Dendi,战术大师Purppey,K神KuroKy,飘逸Carry XBOCT这些知名的选手。     

Carbohydrate ingestion improves endurance performance during a 1h simulated cycling time trial

This study examined the effect of carbohydrate ingestion on metabolic and performance-related responses during and after a simulated 1h cycling time trial. Eight trained male cyclists (VO 2 peak = 66.5ml kg -1 min -1 ) rode their own bicycles mounted on a windload simulator to imitate real riding conditions. At a self-selected maximal pace, the cyclists performed two 1h rides (separated by 7 days) and were fed either an 8% carbohydrate or placebo solution. The beverages were administered 25 min before (4.5ml kg -1 ) and at the end (4.5ml kg -1 ) of the ride. With carbohydrate feeding, plasma glucose tended (P = 0.21) to rise before the time trial. Compared with rest, the plasma glucose concentration decreased significantly (P < 0.05) at the end of both rides, with no statistically significant difference being observed between treatments. Thereafter, plasma glucose increased significantly (P < 0.05) at 15 and 30 min into recovery, and was significantly higher at 30 min during the carbohydrate trial compared with the placebo trial. No significant changes in plasma free fatty acids were observed during the ride. However, a significant increase (P < 0.05) in free fatty acids was found at 15 and 30 min into recovery, with no difference between trials. Mean power output was significantly (P < 0.05) greater during the carbohydrate compared with the placebo trial (mean - S.E.: 277-3 and 269-3W, respectively). The greater distance covered in the carbohydrate compared with the placebo trial (41.5-1.06 and 41.0–1.06km, respectively; P < 0.05) was equivalent to a 44s improvement. We conclude that pre-exercise carbohydrate ingestion significantly increases endurance performance in trained cyclists during a 1h simulated time trial. Although the mechanism for this enhancement in performance with carbohydrate ingestion cannot be surmised from the present results, it could be related to a higher rate of carbohydrate oxidation, or to favourable effects of carbohydrate ingestion on the central component of fatigue.     

Science and medicine of rowing: A review

The biology and medicine of rowing are briefly reviewed. Effort in a 2000 -m race is about 70% aerobic. Because the boat (and in some instances a cox) must be propelled, successful competitors are very tall, with a large lean mass and aerobic power. Large hearts may lead to erroneous diagnoses of a cardiomyopathy. Large respiratory minute volumes must be developed by chest muscles that are also involved in rowing. The vital capacity is typically large, and breathing becomes entrained. Expiration cannot be slowed relative to inspiration (as normally occurs at high rates of ventilation) and the limiting flow velocity may be reached, with the potential for airway collapse. Performance is strongly related to the power output at the ‘anaerobic threshold’, and lactate measures provide a guide to an appropriate intensity of endurance training. Peak blood lactate levels are higher in males (commonly 11–19 mmol·l -1 and occasionally as high as 25 mmol·l -1) than in females (9–11 mmol·l -1), probably because males have a greater muscle mass in relation to blood volume. The skeletal muscles are predominantly slow twitch in type, developing an unusual force and power at low contraction velocities. Many rowers have a suboptimal diet, eating excessive amounts of fat. Lightweight rowers also have problems of weight cycling. Aerobic power and muscle endurance often change by 10% over the season, but such fluctuations can be largely avoided by a well-designed winter training programme. Injuries include back and knee problems, tenosynovitis of the wrist and, since the introduction of large blades, fractures of the costae.     

Identifying home advantage in international tennis and golf tournaments

A regression analysis of competitors' tournament results in relation to their world rankings was proposed to identify the effect of home advantage in international ‘grand-slam’ tennis and ‘major’ golf tournaments. The results provided little evidence of home advantage in either the grand-slam tennis or the golf tournaments held in 1993. The only possible evidence of home advantage was found in the Wimbledon tennis and the US Open golf championships. Even these findings can be explained, at least partially, by (1) the availability of information concerning the low world rankings of the British tennis players competing at Wimbledon, and (2) selective entry, allowing only the world's top-ranked foreign golfers into the US open golf tournament. In both cases, the lower ranking home competitors have a greater opportunity to perform above their anticipated world rankings. Therefore, provided entry into tennis and golf tournaments is truly ‘open’ to both the host nation's representatives and foreign competitors alike, home advantage does not appear to be a major factor influencing the competitors' performance in such competitions. These findings may be explained by the relatively objective nature of the scoring systems used in tennis and golf, unlike the subjective influence of refereeing decisions on the results of team-games such as soccer.     

全国城乡学生体质20年动态分析

基于1985、1995和2005年全国学生体质调研数据,对各时期我国城乡学生形态、机能、体能发展水平进行系统地定量研究,动态分析20年全国城乡学生体质发展的特点与规律。主要研究结果：（1）近20年城乡学生生长发育持续提前,城市学生各项形态指标生长水平高于乡村,身高城乡差距缩小,体重、胸围城乡差距加大;（2）城市学生肺活量水平高于乡村,城乡学生肺活量20年持续下降,前10年乡村学生下降快、后10年城市学生下降快;（3）乡村学生800m、1000m跑水平高于城市,城市女生50m跑、仰卧起坐水平高于乡村,其他素质城乡学生水平波动较大;（4）城市女生50m跑20年持续下降,城乡学生800m和1000m跑、城市学生50m×8往返跑20年加速下降,其他素质20年间有增有降发展极不平稳。     

定向运动对大学生身心健康发展的实践研究

采用测量、问卷调查、数理统计等方法,分析定向运动学习前后对大学生身心健康的影响.结果经T检验和x2检验且表明：定向运动不仅能增强学生体质健康水平,而且有助于学生的情绪调节,增强自信心与创新意识,培养勇敢顽强的意志品质,建立良好的人际关系,能有效地促进学生身心健康发展.为了全面提高大学生整体素质,积极实践,构建定向运动课内外一体化教学模式,进行定向运动课程模块化教学,以满足学生的多元化需求.     

我国体育市场管理法规研究

采用调查法和比较法对全国体育市场立法和管理现状进行调查,对部分较早出台并有一定代表性的省市的体育市场管理法规的立法和管理情况进行了研究,提出了体育市场管理立法和管理的原则、基本程序、措施及其一般模式,为规范全国体育市场管理提供参考依据。     

重新认识体育的社会关联

体育与政治之间存在一个悖论，体育的发展与经济实力之间没有直线相关，体育与教育部分重叠，体育与宗教最为近缘，体育可借用科学手段，体育的艺术禀性日益明显，体育与养生反映着两种人生观。     

上海社区体育竞赛参与者的特点探析

本文在专家访谈、问卷调查、数理统计和文献资料分析的基础上,探析了上海社区体育竞赛参与者的特点、参与者对社区体育赛事运作管理的看法等问题。在此基础上从引进社区体育赛事的志愿者、整合社区体育赛事的各种资源、开发社区体育竞赛的无形资产、组建非营利性的专业团队、规范社区体育赛事的服务管理等方面提出了进一步满足上海社区居民日益增长的体育竞赛参赛需求的对策与措施。     

对全面把握游泳训练环节的探讨

从系统观点出发,结合训练实践,对全面把握游泳训练环节进行探讨。认为应强化非智力因素在运动员多年训练中的作用,在育材全过程中不断选材,从整体上把握动态训练的全过程,把培养高水平运动员的整个过程置于一个严格的科学控制之下。     

我国优秀游泳运动员出发技术辅助训练的研究

为改进我国优秀游泳运动员的出发技术,采用观测和实验方法,通过拍摄运动员陆上和水下出发技术录像以及出发计时,对出发技术进行运动生物力学诊断和分析。在此基础上,根据运动员自身特点和不同泳姿提出相应的入水启动方式,并研制出发训练辅助器材,对出发预备姿势、腾起角度以及飞行远度和入水角进行控制。实践证明:这是一种快捷、有效的出发技术辅助训练方法。