Mechanisms underlying reductions in stroke volume at rest and during exercise at high altitude     

Mike Stembridge  Philip N. Ainslie  Rob Shave 《European Journal of Sport Science》2016,16(5):577-584

High-altitude exposure challenges the cardiovascular system to maintain oxygen delivery to the mitochondria under conditions of hypoxic stress. Following acclimatisation (3–5 days), stroke volume (SV) falls to below sea-level values but heart rate remains elevated, such that cardiac output is maintained compared to sea level. The decrease in SV has been a topic of research for over 40 years, but the underlying mechanisms are incompletely understood. Impaired systolic contractile function secondary to reduced coronary arterial oxygen tension has been investigated as a potential cause for the decrease in SV. However, despite in vitro evidence of impaired cardiac contractile force in severe hypoxia, the majority of studies to date have reported enhanced in vivo ventricular systolic function at rest and during exercise in humans up to and above 5000?m. However, the elevated function observed at rest has recently been suggested to reduce the functional reserve available during exercise. While in vivo systolic function appears enhanced at high altitude, a decrease in left ventricular end-diastolic volume (EDV) and altered filling patterns of both ventricles has been observed. The reduction in ventricular filling will undoubtedly affect SV, and four potential mechanisms have been proposed to explain the reduction in left ventricular filling. In this article, both historical and recent reports of systolic function at high altitude will be reviewed, and evidence supporting and refuting each of the four mechanisms underpinning reduced left ventricular filling will be discussed.  相似文献   

不同海拔高度低氧暴露及运动对大鼠氧传递能力的影响     

杜霞  藤井久雄  苏青青  马延峰  马福海 《福建体育科技》2016,(4):24-27

对大鼠采用不同海拔及组合模式的低氧暴露和运动方法,通过红细胞等指标探讨不同海拔高度下的低氧适应和机体氧传递能力。方法：9周龄wistar雄性大鼠80只（体重269.38±6.24g）,分为非运动组和运动组两大组。每组分为0m、2200m、2200＋3500m、3500m共4组,每小组10只。其中运动组大鼠每天在时速设定为20－22m／mim、坡度0°的跑台上训练90分钟,每周5天共6周。结果：3500m及以下的4种不同海拔高度下无论是低氧暴露还是运动,红系细胞RBC、 Hb、 Hct均表现随海拔的升高而升高,而运动组的升高幅度更为显著,同时2200＋3500m组合式模式无论是运动组还是非运动组均出现了最高峰值。结论：在不同海拔环境下低氧是影响血细胞升高的重要因素,但低氧环境下复合运动负荷更能促进血细胞RBC、 Hb、 Hct生成,且2200＋3500 m组合式模式更能有效的促进红系细胞生成量,从而更有利于提高机体氧传递能力和有氧能力。  相似文献   

低氧减肥的研究及应用     

邓潇潇  吴红豫 《福建体育科技》2016,(2)

采用综述的方法,分析了低氧运动减肥的科学性,以及低氧在大众健康促进中的应用,得出主要结论：多数低氧暴露结合中等强度有氧运动对于脂肪代谢有积极作用,在降低体重的同时可能有利于身体成分的良好改变,提高身体健康程度,低氧对于大众健康的促进也有一定意义。建议：后续研究应提出针对青少年的个性化训练方案,例如结合个体最大脂肪代谢率等;未来应进一步确认是否低氧训练可作为一种新的减体重同时治疗肥胖相关疾病的手段,并阐明潜在机制。  相似文献   

低氧、运动对大鼠腓肠肌血管内皮细胞生长因子表达的影响   总被引：2，自引：0，他引：2  

王维群  陆彩凤  姜文凯  雷涛  潘菊芳 《西安体育学院学报》2008,25(6)

选用健康雄性SD大鼠144只，采用ELISA法，研究短期低氧、不同强度常氧运动和高住低练对大鼠腓肠肌VEGF表达的影响。结果表明，低氧和常氧运动诱导的骨骼肌VEGF表达属早期效应，长时间中等强度的运动比间歇性的高强度运动诱导更多的VEGF表达，高住低练削弱了长时间中等强度运动诱导的VEGF表达。  相似文献   

Altitude training in endurance running: perceptions of elite athletes and support staff     

Gareth Turner  Barry W Fudge  Jamie S M Pringle  Neil S Maxwell  Alan J Richardson 《Journal of sports sciences》2019,37(2):163-172

This study sought to establish perceptions of elite endurance athletes on the role and worth of altitude training. Elite British endurance runners were surveyed to identify the altitude and hypoxic training methods utilised, along with reasons for use, and any situational, cultural and behaviour factors influencing these. Prior to the 2012 Olympics Games, 39 athletes and 20 support staff (coaches/practitioners) completed an internet-based survey to establish differences between current practices and the accepted “best-practice”. Almost all of the athletes (98%) and support staff (95%) surveyed had utilised altitude and hypoxic training, or had advised it to athletes. 75% of athletes believed altitude and hypoxia to be a “very important” factor in their training regime, with 50% of support staff believing the same. Athletes and support staff were in agreement of the methods of altitude training utilised (i.e. 'hypoxic dose’ and strategy), with camps lasting 3–4 weeks at 1,500–2,500 m being the most popular. Athletes and support staff are utilising altitude and hypoxic training methods in a manner agreeing with research-based suggestions. The survey identified a number of specific challenges and priorities, which could provide scope to optimise future altitude training methods for endurance performance in these elite groups.  相似文献   

低氧运动改善肥胖大鼠胰岛素抵抗中Caveolin的变化     

张荷  周越  张一民 《北京体育大学学报》2018,41(7):64-69

摘要：目的：观察低氧运动对大鼠骨骼肌胰岛素抵抗（Insulin Resistance,IR）的影响,并探究小窝蛋白（Caveolin）在该过程中的作用。方法：5周龄雄性SD大鼠46只,随机分为对照组和高脂组,进行8周高脂膳食喂养,通过测定胰岛素敏感性以及葡萄糖耐量试验,判断建模是否成功;建模成功大鼠随机分为常氧安静组（NC）、常氧运动组（NE）、低氧安静组（HC）和低氧运动组（HE）,进行4周低氧运动干预。测定各组大鼠胰岛素敏感性,免疫荧光观察GLUT4在大鼠比目鱼肌细胞内的分布,Western blot测定比目鱼肌GLUT4、Caveolin-1、Caveolin-3的蛋白含量。结果：1）大鼠在8周高脂膳食后出现胰岛素抵抗;2）4周低氧运动使得大鼠体重明显下降,且胰岛素敏感性明显升高,糖耐量受损程度减轻;3）低氧运动诱导GLUT4在比目鱼肌细胞膜上的分布明显增加,且GLUT4的蛋白表达增多;4）与NC组相比,HE组Caveolin-3的蛋白含量显著升高。结论：低氧运动能有效改善肥胖诱导的胰岛素抵抗,同时可促进GLUT4的生成及其在骨骼肌细胞内分布,Caveolin-3含量在此过程中出现升高。  相似文献   

低氧运动对骨骼肌自由基代谢的影响     

李一新  刘仁仪 《湘南学院学报》2010,31(5)

在运动过程中,机体内可出现负荷性低氧.低氧训练能有效增强人体运动机能,骨骼肌在短期或长期低氧应激作用下会产生一系列代偿性反应,从而改善自身代谢状况,提高低氧适应能力,促进低氧习服.自由基对机体作用具有双面性,在不适当的低氧运动负荷作用下,自由基代谢失平衡将造成骨骼肌细胞损伤和凋亡,而合理的低氧运动刺激能增强机体和骨骼肌的抗氧化能力和自由基清除能力.关于运动性内源自由基生成可能涉及线粒体机制、黄嘌呤氧化酶机制、中性粒细胞机制和钙机制等多个途径.  相似文献   

缺氧诱导脑红蛋白表达及运动生物学应用展望     

邢维新  田振军 《体育学刊》2012,(1):139-144

脑红蛋白(Ngb)是新近发现的神经系统特异的携氧球蛋白,主要在脊椎动物脑组织中高表达,与脑内氧供应密切相关。研究表明,缺氧能够诱导Ngb的表达,而高表达的Ngb能够保护神经元免受缺氧损伤,从而在神经系统缺氧、缺血损伤中具有重要的神经保护功能。从Ngb的生物学特征研究出发,对Ngb在医学中的研究现状做一综述,并对Ngb在体育科学中的应用前景进行展望。  相似文献   

"高住低训"后力竭运动对小鼠大脑HIF-1α蛋白表达及NOS/NO的影响     

杨品良  廖敏 《山东体育学院学报》2007,23(1):56-59

目的:了解“高住低训”下力竭运动对小鼠大脑内HIF-1蛋白表达和NOS/NO系统的影响。方法:30只4周雄性小鼠随机分成5组,常氧对照组(NC)、常氧训练组(NT)、低氧对照组(HC)、高住低训组(HT)、高住低训注射药物CHX组(HTC),每个训练组分别进行9周每天1小时的游泳训练,最后一次力竭运动后断头处死,比较常压有氧训练和模拟“高住低训”的小鼠大脑HIF-1蛋白表达和NOS活性NO含量的变化。结果:“高住低训”组与常压常氧训练组比较,HIF-1表达量明显减少,cNOSi、NOS活性明显提高,NO含量明显增加。结论:“高住低训”组小鼠大脑组织逐渐适应了低氧刺激。  相似文献   

间歇性低氧训练对大鼠血清T、C和LH的影响     

王林  张云丽 《辽宁体育科技》2009,31(3):39-41

采用实验法观察间歇性低氧训练对大鼠血清睾酮（T）、皮质醇（C）、T／C比值和黄体生成素（LH）的影响，结果表明：间歇性低氧训练比游泳训练更能促使血清T、T／C比值和血清LH水平的提高，而使C下降更为明显，从而保持高睾酮低皮质醇水平；间歇性低氧训练比游泳训练对大鼠血清激素有更大的影响，暗示其更有利于提高大鼠的运动能力。  相似文献