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1.
少年运动员递增负荷运动中血浆血管紧张素Ⅱ的变化初探   总被引：1，自引：0，他引：1  
采用放射免疫法对１０名少年耐力运动员,在５０Ｗ、１５０Ｗ递增负荷运动中的血浆ＡｎｇⅡ含量进行了动态观察,并以血压（ＢＰ）,心率（ＨＲ）作为参照指标进行监测。结果表明：５０Ｗ、１５０Ｗ负荷运动末血浆ＡｎｇⅡ较安静状态分别上升２０％（Ｐ＞０．０５）、５３％（Ｐ＜０．００１）;ＢＰ、ＨＲ亦明显上升（均为Ｐ＜０．００１）。与对照组相比,在５０Ｗ、１５０Ｗ负荷运动末血浆ＡｎｇⅡ含量呈显著差异。提示：中等强度以上的耐力运动可促少年运动员血浆ＡｎｇⅡ合成释放显著增加  相似文献   

2.
增量运动过程中心率变异性的研究   总被引：12，自引：0，他引：12  
通过对增量运动过程中心电图的记录分析，研究了增量运动过程中心率变异性指标（ＳＤＲＲ、ＳＤＤＲＲ、变异系数）的变化规律。结果显示：增量运动过程中，随运动强度的增加ＳＤＲＲ逐渐减小（５０Ｗ时Ｐ＜０．０５、１２５Ｗ时Ｐ＜０．０１），ＳＤＤＲＲ逐渐减小（５０Ｗ后Ｐ＜０．０５），心率变异系数逐渐减小；心脏内传导（主要是房—室传导）加快（１５０Ｗ时Ｐ＜０．０５）；心室复极化量逐渐减小；运动终止后上述改变逐渐恢复。  相似文献   

3.
为探讨运动条件下血浆血管紧张素Ⅱ、心钠素的变化及相互关系,作者采用放射免疫法对３０名少年运动员在１００Ｗ恒定负荷运动条件下的血浆血糖紧张素Ⅱ、心钠素含量进行了动态测定。结果表明：血浆血管紧张素Ⅱ、心钠素的含量在运动１５分钟时较安静状态分别上升２２％（Ｐ＜０．０１）和１０％（Ｐ＞０．０５）;运动３０分钟后即刻较安静时分别上升５６％（Ｐ＜０．００１）和１６％（Ｐ＜０．００１）。与对照组相比,血浆血管紧张素在各观察指标呈显著差异。结合有关心功能指标提示：中等强度的耐力运动可使心血管组织合成释放血浆血管紧张素Ⅱ,心钠素显著增加。  相似文献   

4.
耗竭运动对大鼠肝脏线粒体能量转换功能的影响   总被引：2，自引：0，他引：2  
以ＳＤ大鼠递增负荷跑台跑为运动模型，观察了耗竭运动对大鼠肝脏线粒体能量转换功能的影响。应用极谱法分别测定了以苹果酸＋谷氨酸为呼吸底物和琥珀酸为呼吸底物时线粒体态４呼吸速率（Ｒ４）、态３呼吸速率（Ｒ３）、呼吸控制比（ＲＣＲ）、及磷氧比（ＡＤＰ／Ｏ）。结果显示，苹果酸＋谷氨酸为呼吸底物时，Ｒ４增加６４．７６％（Ｐ＜０．００１），ＲＣＲ下降１５．０５％（Ｐ＜０．００１），ＡＤＰ／Ｏ下降１２．１７％（Ｐ＜０．０１）。以琥珀酸为底物时，Ｒ４增力０２３．６７％（Ｐ＜０．０５），ＲＣＲ下降１２．３１％（Ｐ＜０．０５），ＡＤＰ／Ｏ下降１１．７６％（Ｐ＜０．０１）。表明高能质子非特异性渗漏增加，氧化磷酸化偶联程度降低。以苹果酸＋谷氨酸为呼吸底物的Ｒ３显著性增高４１．１４％（Ｐ＜０．００１），推测是由体内ＡＴＰ水平下降，致使线粒体呼吸速率代偿性加快。以琥珀酸为底物的Ｒ３略有增高，但没有显著差异。实验结果表明，耗竭运动后肝线粒体苹果酸＋谷氨酸启动的呼吸及琥珀酸启动的呼吸都受到损害。而且，前者损害程度大于后者。  相似文献   

5.
大鼠过度训练时间与血乳酸值变化的关系探讨   总被引：2，自引：0，他引：2  
本文通过大鼠高强度大运动量训练模拟过度训练并进行血乳酸值测定和运动时间动态观察，结果表明：整个训练期间运动后血乳酸值均较对照组显著升高（Ｐ＜０．０１），后期升高幅度较早期、中期显著下降（Ｐ＜０．０５）；每天的运动时间早期到中期逐渐增加，后期显著下降（Ｐ＜０．０５）。因而初步提出了血乳酸值下降的变化可能是过度训练的早期反应，运动能力提高的同时可能潜在过度训练的发生。  相似文献   

6.
本文旨在探讨递增负荷力竭性运动对大鼠心肌和骨骼肌线粒体膜脂质过氧化（ＬＰＯ）水平的影响。采用三级递增负荷跑台跑运动至力竭为运动模型，分别测定运动后即刻大鼠心肌和骨骼肌线粒体丙二醛（ＭＤＡ）含量。发现心肌线粒体ＬＰＯ水平显著性增高（Ｐ＜０．０５）；骨骼肌线粒体ＬＰＯ水平增高，但无显著性（Ｐ＞０．０５）。同时测定心肌和骨骼肌组织ＭＤＡ，也观察到相同的变化规律。提示，递增负荷力竭性运动对心肌和骨骼肌线粒体膜ＬＰＯ水平具有不同程度的影响，可能与运动中心肌和骨骼肌不同代谢应激有关；ＬＰＯ水平增高，将影响线粒体呼吸链氧化磷酸化及ＡＴＰ生成，可能是运动性疲劳的重要膜分子机制之一。  相似文献   

7.
采用递增负荷耗竭运动模型为急性缺氧应激源，观察了ＳＤ大鼠急性运动至力竭后心肌组织和线粒体膜过氧化脂质含量，线粒体内膜ＮＡＤＨ－ＣｏＱ还原酶活性变化和心肌纤维和线粒体超微结构。结果表明，心肌能量需求过高性缺氧应激后大鼠心肌组织匀浆和线粒体膜过氧化脂含量分别增高１４０．９％和３９．４％（Ｐ＜０．０１和Ｐ＜０．０５），线粒体内膜ＮＡＤＨ－ＣｏＱ还原酶活性降低６１．６％（Ｐ＜０．０５），心肌纤维和线粒体超微结构呈缺氧损伤性改变。研究提示，急性运动缺氧应激后心肌组织和心肌线粒体膜结构变化与脂质过氧化作用增强有关  相似文献   

8.
力竭性运动对肝脏线粒体呼吸控制及磷酸化功能的影响   总被引：8，自引：1，他引：8  
以ＳＤ大鼠递增负荷急性力竭跑台运动为疲劳模型,分别测定了运动后即刻肝脏线粒体：（１）以苹果酸＋谷氨酸（Ｍ＋Ｇ）和琥珀酸（Ｓ）为底物的呼吸控制：态３呼吸速率（Ｒ３）、态４呼吸速率（Ｒ４）、呼吸控制比和磷／氧比（Ｐ／Ｏ）。（２）Ｈ＋－ＡＴＰａｓｅ合成活力。结果表明：两种呼吸底物启动的线粒体Ｒ４（质子漏）分别升高６４．４６和２３．５４％（Ｐ＜０．００１和Ｐ＜０．０５）,ＲＣＲ和Ｐ／Ｏ呈显著降低（均Ｐ＜０．０５）;Ｍ＋Ｇ为呼吸底物的Ｒ３也呈显著增加（Ｐ＜０．００１）,Ｓ为呼吸底物的Ｒ３略有增高（Ｐ＞０．０５）;Ｈ＋－ＡＴＰａｓｅ合成活力降低１４．４０％（Ｐ＜０．０５）。研究提示,由线粒体质子漏增加导致质子电化学势能（ΔＰ）的降低直接影响Ｈ＋－ＡＴＰａｓｅ合成活力。  相似文献   

9.
外源性补充辅酶Q 对肝脏线粒体ATP 合成能力的影响   总被引：17，自引：1，他引：16  
以递增负荷次最大强度跑台运动为模型,观察了外源补充辅酶Ｑ（ＣｏＱ）大鼠肝脏线粒体ＣｏＱ１０结合含量和Ｈ＋－ＡＴＰａｓｅ合成活力的影响。实验分为：对照组（ＮＣ）、ＣｏＱ补充组（ＱＣ）、运动组（ＮＥ）和ＣｏＱ补充运动组（ＱＥ）组。结果表明：外源性补充ＣｏＱ和运动应激均显著增加线粒体ＣｏＱ结合含量（Ｐ＜０．０５）;ＱＣ和ＱＥ组Ｈ＋－ＡＴＰａｓｅ合成活力均显著高于ＮＣ组（Ｐ＜０．０５）,且ＱＥ组显著高于ＮＥ组（Ｐ＜０．０５）。研究提示,外源补充ＣｏＱ可能通过增加线粒体呼吸链电子传递速率,改善电子传递与质子泵出偶联状况,提高运动中线粒体ＡＴＰ再合成能力。  相似文献   

10.
本文对１２名男大学生２４小时内不同时间安静时、定量负荷（６０Ｗ、１２０Ｗ、１８０Ｗ）时的心率进行了记录分析，结果显示：①安静时白天心率高于夜间，白天中１０：３０和１６：３０左右时心率较低；②定量负荷后的心率反应也存在昼夜节律现象；③清晨（４：３０）定量负荷时心率增加最快；④一天中运动能力存在两个高峰（１０：３０和１６：３０左右）。  相似文献   

11.
The aim of this study was to determine the variations in substrate utilization between men and women matched for ventilatory threshold (Tvent) during incremental arm cranking and leg cycling exercise at 70, 85, 100 and 115% of the mode-specific Tvent. Recreationally active men (n=12) and women (n=10) with similar values for percentage of peak oxygen consumption at Tvent participated in the study. Ventilatory equivalence, excess CO2 and modified V-slope methods were used concurrently to determine Tvent. The participants performed 5 min of exercise at each of 70, 85, 100 and 115% Tvent during both arm cranking and leg cycling exercise. The females were tested during the early follicular phase for all trials. A two-way mixed-design analysis of variance was performed to test for differences between the sexes. When carbohydrate and fat oxidation were expressed relative to total fat-free mass, carbohydrate oxidation during arm cranking and leg cycling was significantly higher in men than women at each percentage of Tvent. In contrast, women showed significantly higher fat oxidation across intensities during both arm cranking and leg cycling. Our results suggest that when substrate utilization is expressed relative to total fat-free mass, women appear to maintain a higher rate of fat and lower rate of carbohydrate oxidation than men during both incremental arm cranking and leg cycling exercise relative to Tvent.  相似文献   

12.
Abstract

The aim of this study was to determine the variations in substrate utilization between men and women matched for ventilatory threshold (T vent) during incremental arm cranking and leg cycling exercise at 70, 85, 100 and 115% of the mode-specific T vent. Recreationally active men (n = 12) and women (n = 10) with similar values for percentage of peak oxygen consumption at T vent participated in the study. Ventilatory equivalence, excess CO2 and modified V-slope methods were used concurrently to determine T vent. The participants performed 5 min of exercise at each of 70, 85, 100 and 115% T vent during both arm cranking and leg cycling exercise. The females were tested during the early follicular phase for all trials. A two-way mixed-design analysis of variance was performed to test for differences between the sexes. When carbohydrate and fat oxidation were expressed relative to total fat-free mass, carbohydrate oxidation during arm cranking and leg cycling was significantly higher in men than women at each percentage of T vent. In contrast, women showed significantly higher fat oxidation across intensities during both arm cranking and leg cycling. Our results suggest that when substrate utilization is expressed relative to total fat-free mass, women appear to maintain a higher rate of fat and lower rate of carbohydrate oxidation than men during both incremental arm cranking and leg cycling exercise relative to T vent.  相似文献   

13.
We measured the effects of stride rate, resistance, and combined arm-leg use on energy expenditure during elliptical trainer exercise and assessed the accuracy of the manufacturer's energy expenditure calculations. Twenty-six men and women (M age = 29 years, SD = 8; M body weight = 73. 0 kg, SD = 15.2) participated. Twenty-two participants performed two tests, one without the arm poles (leg-only) and the other with arm poles (combined arm-leg). The other 4 participants performed one test without the arm poles. Both tests consisted of six 5-min stages (two stride rates, 110 and 134 stridesmin-1, and three resistance settings: 2, 5, and 8). Steady-state oxygen uptake (VO2), minute ventilation (VE), heart rate (HR) and rating of perceived exertion (RPE) were measured. Repeated measures analysis of variance determined higher (p <. 001) VO2, VE, and RPE, but not HR, during combined arm-leg versus leg-only exercise at any given intensity. Increases in stride rate and resistance increased VO2, VE, RPE, and HR with the greatest effect on VE and HR from Levels 5 to 8. The manufacturer's calculated energy expenditure was overestimated during both tests. Although the oxygen cost for elliptical trainer exercise was calculated to be approximately 0.1 mlxkg(-1) per stride and 0.7 mlxkg(-1) min-1 per resistance level, VO2 varied widely among individuals, possibly due to differences in experience using the elliptical trainer gender, and body composition. The elliptical trainer offers (a) a variety of intensities appropriate for most individuals and (b) both arm and leg exercise. Due to the wide variability in VO2, predicting the metabolic cost during elliptical trainer exercise for an individual is not appropriate.  相似文献   

14.
Following preliminary indications that in some individuals arm exercise enhanced rather than reduced simultaneous leg endurance, ten young men and women performed three forms of intermittent work to volitional exhaustion, under duty cycles of 45 s work, 15 s rest. The protocols were as follows: (A) knee extensions at 30% maximum voluntary contraction (MVC); (B) 30% MVC knee extensions combined with arm cranking at 130% of their own lactate threshold; (C) combined 30% MVC knee extensions and arm cranking at 20% of their own lactate threshold. Heart rate, oxygen uptake (VO(2)), and blood lactate concentration were among the variables recorded throughout. All physiological indicators of demand were substantially higher in protocol B than in protocols A or C [heart rate: (A) 154 beats . min(-1), (B) 171 beats . min(-1), (C) 150 beats . min(-1); VO(2): (A) 11.9 ml . kg(-1) . min(-1), (B) 21.7 ml . kg(-1) . min(-1), (C) 14.2 ml . kg(-1) . min(-1); blood lactate concentration: (A) 3.3 mmol . l(-1), (B) 5.1 mmol . l(-1), (C) 2.8 mmol . l(-1)], yet there were no significant differences (P > 0.05) in the endurance times between the three conditions [(A) 11.43 min, (B) 11.1 min, (C) 10.57 min] and seven participants endured longest in protocol B. Results from protocol (C) cast doubt on explanations in terms of psychological distraction. We suggest that lactic acid produced by the arms is shuttled to the legs and acts there either as a supplementary fuel source or as an antagonist to the depressing effects of increased potassium concentration.  相似文献   

15.
We measured the effects of stride rate, resistance, and combined arm-leg use on energy expenditure during elliptical trainer exercise and assessed the accuracy of the manufacturer's energy expenditure calculations. Twenty-six men and women (M age = 29 years, SD = 8; M body weight = 73.0 kg, SD = 15.2) participated. Twenty-two participants performed two tests, one without the arm poles (leg-only) and the other with arm poles (combined arm-leg). The other 4 participants performed one test without the arm poles. Both tests consisted of six 5-min stages (two stride rates, 110 and 134 strides.min-1, and three resistance settings: 2, 5, and 8). Steady-state oxygen uptake (VO2), minute ventilation (VE), heart rate (HR) and rating of perceived exertion (RPE) were measured. Repeated measures analysis of variance determined higher (p < .001) VO2, VE, and RPE, but not HR, during combined arm-leg versus leg-only exercise at any given intensity. Increases in stride rate and resistance increased VO2, VE, RPE, and HR with the greatest effect on VE and HR from Levels 5 to 8. The manufacturer's calculated energy expenditure was overestimated during both tests. Although the oxygen cost for elliptical trainer exercise was calculated to be approximately 0.1 ml.kg-1 per stride and 0.7 ml.kg-1.min-1 per resistance level, VO2 varied widely among individuals, possibly due to differences in experience using the elliptical trainer, gender, and body composition. The elliptical trainer offers (a) a variety of intensities appropriate for most individuals and (b) both arm and leg exercise. Due to the wide variability in VO2, predicting the metabolic cost during elliptical trainer exercise for an individual is not appropriate.  相似文献   

16.
Abstract

The bradycardia effect of a 10-week jogging program was studied in 13 previously sedentary middle-aged subjects (seven women and six men). This response during standardized submaximal treadmill walking and leg cycling was related to changes in cardiac output ([Qdot]), stroke volume (SV), and arteriovenous oxygen differences (a-vO2 diff). Heart rate (HR) response was also studied during load carrying and arm cycling tasks, and a [Vdot]O2 max test was administered. All tests were repeated posttraining. The posttraining increases in [Vdot]O2 max (ml/kg × min-1) were 19.7% and 14.8% for the men and women respectively. Training also produced significant reductions in submaximal HR and Q during treadmill and leg cycling exercise. A-vO2 diff rose, while there were no changes in [Vdot]O2 during the submaximal work tasks, suggesting either altered blood flow or a greater capacity to utilize O2 by the working muscle. Both men and women showed significant reductions in HR during the arm cycling and load carrying as well. These data suggest that a jogging program can alter cardiovascular function in tasks other than running. The magnitude and direction of change showed no sex differences; therefore, it was also concluded that there are no differences in the trainability of previously sedentary middle-aged men and women.  相似文献   

17.
The aim of this study was to determine the relationship between force and velocity parameters during a specific multi-articular upper limb movement--namely, hand rim propulsion on a wheelchair ergometer. Seventeen healthy able-bodied females performed nine maximal sprints of 8 s duration with friction torques varying from 0 to 4 N x m. The wheelchair ergometer system allows measurement of forces exerted on the wheels and linear velocity of the wheel at 100 Hz. These data were averaged for the duration of each arm cycle. Peak force and the corresponding maximal velocity were determined during three consecutive arm cycles for each sprint condition. Individual force-velocity relationships were established for peak force and velocity using data for the nine sprints. In line with the results of previous studies on leg cycling or arm cranking, the force-velocity relationship was linear in all participants (r = -0.798 to -0.983, P < 0.01). The maximal power output (mean 1.28 W x kg(-1)) and the corresponding optimal velocity (1.49 m x s(-1)) and optimal force (52.3 N) calculated from the individual force-velocity regression were comparable with values reported in the literature during 20 or 30 s wheelchair sprints, but lower than those obtained during maximal arm cranking. A positive linear relationship (r = 0.678, P < 0.01) was found between maximal power and optimal velocity. Our findings suggest that although absolute values of force, velocity and power depend on the type of movement, the force-velocity relationship obtained in multi-articular limb action is similar to that obtained in wheelchair locomotion, cycling and arm cranking.  相似文献   

18.
Abstract

The effects of active recovery using previously active and inactive muscle groups on power output and respiratory responses were examined. Ten male volunteers underwent two exhaustive 40-s bouts of leg cycling (1st Ex and 2nd Ex), separated by a 20-min recovery period. The recovery conditions were leg (Leg-Active) or arm (Arm-Active) cranking at 50% ventilatory threshold (VT), or sedentary control (Passive). The total output work (Total work) during the 2nd Ex in the Leg-Active condition was significantly higher than that in the Passive (299 vs. 282 J · kg body mass?1 (J · BM?1)). The values of Total work, peak [Vdot]O2 and peak heart rate during the 2nd Ex were significantly higher than those during the 1st Ex in both Leg- and Arm-Active. Total CO2excess after the 1st Ex was significantly higher than that after the 2nd Ex (67.6 vs. 26.0 ml · BM?1) in Passive. After the 2nd Ex, the Total CO2excess in the Leg-Active (51.5 ml · BM?1) was significantly higher than that in both the Passive (26.0) and Arm-Active (36.5), with Arm-Active being significantly higher than Passive. The recovery exercise using previously inactive muscles improved respiratory compensation ability related to performance enhancement.  相似文献   

19.
We examined the effects of concomitant increases in crank rate and power output on incremental arm crank ergometry. Ten healthy males undertook three incremental upper body exercise tests to volitional exhaustion. The first test determined peak minute power. The subsequent tests involved arm cranking at an initial workload of 40% peak minute power with further increases of 10% peak minute power every 2 min. One involved a constant crank rate of 70 rev · min(-1), the other an initial crank rate of 50 rev · min(-1) increasing by 10 rev · min(-1) every 2 min. Fingertip capillary blood samples were analysed for blood lactate at rest and exhaustion. Local (working muscles) and cardiorespiratory ratings of perceived exertion (RPE) were recorded at the end of each exercise stage. Heart rate and expired gas were monitored continuously. No differences were observed in peak physiological responses or peak minute power achieved during either protocol. Blood lactate concentration tended to be greater for the constant crank rate protocol (P = 0.06). Test duration was shorter for the increasing than for the constant crank rate protocol. The relationship between local RPE and heart rate differed between tests. The results of this study show that increasing cadence during incremental arm crank ergometry provides a valid assessment of peak responses over a shorter duration but alters the heart rate-local RPE relationship.  相似文献   

20.
心率变异性各指标在运动适应性评定中的应用   总被引：2，自引：0，他引：2  
目的:通过测量摔跤运动员在大运动量训练期间心率变异性各指标的变化,观察大运动量训练对运动员心脏自主神经功能的影响,初步探讨心率变异性各指标在人体运动适应性评价上的应用。方法:选取摔跤运动员15人,分为优秀组(10人)和普通对照组(5人),在大运动量训练期间,连续三周进行心率变异性测试,获得其时域、频域各指标。结果:优秀组时域各指标参数中SDNN、RMSSD、SDSD在第三周出现增高,PNN50在第二周及第三周出现持续增高(P<0.05);频域法各指标参数中TP、HF、HFnorm、LFnorm在第三周出现增高,LF在第二周及第三周出现持续增高,LF/HF在第三周出现下降(P<0.05)。对照组时域各指标参数均无明显变化;在频域指标中HFnorm在第二周及第三周出现降低,LFnorm、LF/HF在第二周及第三周出现增高(P<0.05)。结论:伴随交感神经张力增加,以迷走神经功能加强为主导的自主神经功能提高是人体对运动负荷产生适应的表现。应用心率变异性对自主神经功能进行测定是理想的评定人体运动适应性的方法。  相似文献   

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