水、电解质在运动中的变化及其调节机制

研究水和电解质在运动中的变化规律及其调节机制。以16名身体健康的男子,参加持续时间为1小时、强度为60%最大摄氧量的运动。分别在运动前(R)、中(D)及休息(R)期间测定血及尿中钾、钠离子;血、尿渗透压;同时还测定血浆醛固酮(ALD)、精氨酸加压素(AVP)、心钠素(ANP)。结论:运动中水分和电解质的丢失明显。ALD、AVP是非常重要的体液调节激素,在运动中对维持水和电解质的平衡起到重要的作用。     

日周期节律变化在运动中对体液调节激素、电解质及血浆容量的影响

目的:研究运动中人体日周期节律变化对体液调节激素及电解质、血浆容量产生的影响.方法:16名身体健康的男性大学生参加二次、相隔一周的功率自行车运动实验(分别在早晨5:00和下午5:00),受试者以心率140次/min运动1 h,之后休息1 h.分别在运动前、中和休息期间测定血浆心钠素(ANP)、醛固酮(ALD)、精氨酸加压素(AVP)、血红蛋白(Hb)、红细胞压积(Hct),血、尿渗透压(Osm)和血、尿钠(Na )、钾(K )离子等,同时测定血浆容量(△PV)和体重(△W)的变化.结果:运动前ANP(早晨:42.1±3.2,下午:33.9±1.5 Pg/ml,P=0.0096)、ALD(早晨:92±10,下午:57±5 Pg/ml,P=0.0005)和AVP(早晨:25.5±0.5,下午:22.7±0.8Pg/ml,P=0.0013)早晨比下午高,呈现昼夜节律变化,它们在运动中明显升高,而且早晨和下午的节律性差异在运动中仍然明显.在早晨运动比下午运动导致更多的血浆容量的减少(早晨:-7.2±3%,下午:-4.5±2%,P=0.02)和体重的下降(早晨:1.03±0.2,下午:0.87±0.1,P=0.0235).结论:①体液调节激素呈现早晨高下午低的昼夜节律变化,这种节律变化在运动中仍然明显,对维持体液平衡起到重要的作用;②运动导致的脱水在早晨比在下午更严重,提示在早晨不适宜从事大负荷运动、训练,可能导致严重的脱水.     

运动对体液调节激素心钠素和醛固酮的影响

心钠素和醛固酮是体内重要的体液调节激素,运动会引起血浆心钠素(ANP)、醛固酮(ALDO)的增高,血浆心钠素(ANP)随运动强度的增加而增加,系统合理的运动训练能提高血浆心钠素水平,力竭运动血浆ANP含量过度增高,增加潜在的心肌受损的可能性。运动中血浆醛固酮(ALDO)浓度与运动强度和脱水程度相关,血浆心钠素(ANP)与机体脱水程度关系不大。运动中检测心钠素、醛固酮浓度的变化对合理制定运动强度、科学指导运动训练具有重要意义。     

择时运动对神经体液调节激素的影响

目的：依据人体生物节律,探讨择时有氧运动对人体神经体液调节激素的影响。方法：20名健康青年男性以最大心率80％进行有氧运动,运动形式为蹬功率自行车,两次择时运动时间为上午6：00-7：00和下午16：00-17：00,随后的1小时为恢复期,以同一时间安静时为对照,从开始运动至恢复期结束,每30min取血一次,测定血液中皮质醇、NE、ANP和ALD的含量。结果：安静时血液中皮质醇、ANP和ALD水平上午高于下午,NE水平上午低于下午。运动时,血液皮质醇、NE、ANP和ALD水平均显著升高。上午运动与下午运动比较,皮质醇、ANP和ALD水平上午高于下午,NE水平下午高于上午。结论：机体皮质醇、NE、ANP和ALD水平均呈近日节律变化的特征。有氧运动时,皮质醇、NE、ANP和ALD水平均升高,并在运动后恢复期下降。上午有氧运动与下午有氧运动时,皮质醇、NE、ANP和ALD水平依然存在节律性变化。     

大强度训练对散打运动员心血管ET、CGRP、ANP水平的影响

采用放射免疫方法测定9名优秀散打运动员安静时血浆心血管激素,即内皮素(endothelin,ET),降钙素基因相关肽(calcitoningenerelatedpeptide,CGRP)和心钠素(atrialnatriureticpeptide,ANP)水平。经3个月的大强度训练,血浆ET水平逐渐升高,到最后两次取样时的变化明显,提示血浆儿茶酚胺、血管紧张肽分泌增加和(或)骨骼肌和心肌损伤可导致该激素水平提高;自训练开始,血浆CGRP水平依次降低,随着训练的深入其变化明显,表明长时期训练的效果异于急性运动;在大强度训练的进程中ET/CGRP比值逐渐升高,说明运动造成两种激素分泌不匹配;血浆ANP随着训练的深入逐渐升高,并最后两次取样变化明显,说明该激素对训练比较敏感;另外ET和CGRP、CGRP和ANP变化之间有明显的负相关,ET和ANP之间存在明显的正相关;研究显示血液指标的变化与血液浓缩无关。     

论运动能力与补充液体

运动员在运动过程中补充体液有助于能量物质的合成和分解、养料和氧气的运送、维持体温调节。所以,保持正常的电解质和水平衡十分重要。合理保持体液可使体温降低,保持血浆容量,还可减缓心率。因此,这些生理反应好与坏将会直接影响运动成绩。     

低氧力竭运动对血浆心钠素和内皮素浓度的影响

目的探讨低氧条件下力竭运动对心血管调节激素血浆心钠素(ANP)、内皮素(ET-1)浓度变化的影响。方法选取8名体育学院男生进行直立蹬自行车运动试验,分别进行常氧运动(N)和低氧运动(H),测定运动至力竭的时间以及运动前(静坐10min)、运动后即刻、运动后3min、运动后30min受试者心率、血压、血浆渗透压和血浆ANP、ET-1浓度的变化。结果 (1)运动后即刻,N组血浆ANP、ET-1浓度显著升高(P<0.05),H组血浆ANP、ET-1浓度非常显著性升高(P<0.01),两组间血浆ANP和ET-1升高幅度具有显著性差异(P<0.05);(2)运动后即刻,N组和H组血浆渗透压均显著升高(P<0.05);(3)与H组相比,N组运动至力竭时间显著较长(P<0.05);(4)运动后30min,两组血浆渗透压仍显著高于安静时(P<0.05)。(5)运动后即刻,两组心率较安静时均显著升高(P<0.001),至运动后30min,心率虽然都有一定恢复,但仍显著高于安静状态(P<0.05)。结论低氧力竭运动可使心血管组织合成释放ANP、ET-1适度增加,对机体产生有益的影响。     

瘦素(Leptin)的生理作用机制及长期运动对其水平的影响

采用文献资料法,分析瘦素(Leptin)的生理作用机制及长期运动对其水平的影响。结果显示:ob基因编码的Leptin具有降低脂肪含量,维持能量平衡,调节代谢、生殖、激素分泌,提高免疫机能等多方面的功能。长期运动对Leptin的影响较为复杂,除了体脂变化、能量平衡变化和激素水平变化等因素外,可能还有未知因素,需要更多的实验探究长期运动对Leptin调节的作用机制。     

模拟4800m低氧环境训练的适应效果研究

目的:对20名平原受试者进行为期3周递增性低氧训练,测试其低氧训练前后模拟海拔4 800m(PO2为10.4%～10.8%)时血清抗利尿激素(AVP)和醛固酮(ALD)的变化,并结合AMS评分、心率和血压,探讨递增性低氧训练对模拟高海拔低氧环境的适应效果。方法:阶段1:受试者于模拟海拔4 800m低氧环境中急性暴露6 h,以60rpm、80 W的定量负荷仰卧蹬车20 min,LLS量表评价AMS,测试低氧暴露过程中的HR和BP,低氧结束时的血清AVP和ALD;阶段2:进行3周递增性低氧训练后,再重复阶段1的测试。结果:低训后模拟海拔4 800m低氧环境下,AMS评分大于等于3分的人数由9人降到2人;运动时的心率明显低于低训前;急性低氧暴露6h,血清AVP和ALD均较常氧值显著下降;低训3周后再次低氧暴露,血清AVP和ALD与常氧值相比较,均无显著差异。结论:递增性低氧训练有助于增强机体对低氧的习服。     

运动强度对人体血浆激素水平的影响

肌肉运动使人体能量代谢发生较大的变化,使肌肉能持续运动。但是,能量代谢受到激素的调节。血浆激素水平又是由运动影响决定的。在运动中.调节能量代谢的一些激素如儿茶酚(酉安),氢基皮质酮,高血糖糖原质分解因子,生长激素和胰岛素等,已经在广泛研究。但是,这些激素的特殊功能仍未确定下来。雄性激素主要由睾丸分泌。雄性激素对人体发育和维持、第二性特征的重要性已得到普遍的承认。但几乎没有人知道成人雄性激素对人体其它功能所起到的重要调节作用。在特定情况下(如贫血或有生理缺陷的情况)雄性激素可增加红血球总数和减轻体重,这都是提高人体运动能力的一些有利因素。     

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.     

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。     

运动性呼吸肌疲劳与耐力性项目的运动能力

影响和限制耐力性运动项目的成绩的生理因素是复杂的和多方面的,取决于训练的强度和运动成绩.大强度持续性运动可导致呼吸肌疲劳.运动性呼吸疲劳可能在决定运动耐量方面起到关键的作用：一方面通过直接影响运动肌力量的生成（外周疲劳）,另一方面,通过肢体用力自感不安反馈引起工作肌运动单位输出功率下降（中枢疲劳）.对呼吸肌进行训练,可能有助于提高耐力性项目的运动成绩.     

青少年业余足球运动员运动倾向性5因素结构模型初探

根据Scanlan等人最新提出的运动倾向性理论模型,结合我国实际情况建立了青少年足球运动员运动倾向性5因素结构模型。运动倾向性被定义为:渴望和决心继续参加足球运动的心理状态。所建立的5因素结构模型认为,运动倾向性是由运动乐趣、参与选择、个人投入、社会约束及参与机会5个因素决定。经确定5个决定因素和运动倾向性的操作定义,编制了相应调查问卷,通过对北京市252名青少年足球运动员实测结果,建立运动倾向性及其影响因素的协方差结构模型,用Lisre 18分析的结果表明:该运动倾向性模型比较符合北京青少年足球运动员。其中运动乐趣、个人投入、参与机会和参与选择4因素对运动倾向性有影响;社会约束对运动倾向性影响不大。     

Effect of 6 weeks of endurance training on the lactate minimum speed

The aim of this study was to assess the sensitivity of the lactate minimum speed test to changes in endurance fitness resulting from a 6 week training intervention. Sixteen participants (mean +/- s :age 23 +/- 4 years;body mass 69.7 +/- 9.1 kg) completed 6 weeks of endurance training. Another eight participants (age 23 +/- 4 years; body mass 72.7 +/-12.5 kg) acted as non-training controls. Before and after the training intervention, all participants completed: (1) a standard multi-stage treadmill test for the assessment of VO 2max , running speed at the lactate threshold and running speed at a reference blood lactate concentration of 3 mmol.l -1 ; and (2) the lactate minimum speed test, which involved two supramaximal exercise bouts and an 8 min walking recovery period to increase blood lactate concentration before the completion of an incremental treadmill test. Additionally, a subgroup of eight participants from the training intervention completed a series of constant-speed runs for determination of running speed at the maximal lactate steady state. The test protocols were identical before and after the 6 week intervention. The control group showed no significant changes in VO 2max , running speed at the lactate threshold, running speed at a blood lactate concentration of 3 mmol.l -1 or the lactate minimum speed.In the training group, there was a significant increase in VO 2max (from 47.9 +/- 8.4 to 52.2 +/- 2.7 ml.kg -1 .min -1 ), running speed at the maximal lactate steady state (from 13.3 +/- 1.7 to 13.9 +/- 1.6 km.h -1 ), running speed at the lactate threshold (from 11.2 +/- 1.8 to 11.9 +/- 1.8 km.h -1 ) and running speed at a blood lactate concentration of 3 mmol.l -1 (from 12.5 +/- 2.2 to 13.2 +/- 2.1 km.h -1 ) (all P ? 0.05). Despite these clear improvements in aerobic fitness, there was no significant difference in lactate minimum speed after the training intervention (from 11.0 +/- 0.7 to 10.9 +/- 1.7 km.h -1 ). The results demonstrate that the lactate minimum speed,when assessed using the same exercise protocol before and after 6 weeks of aerobic exercise training, is not sensitive to changes in endurance capacity.