不同运动强度下恢复期心率推测运动心率的探讨

目的：研究不同运动强度下恢复期心率随恢复时间的变化特征,探讨恢复期心率与运动心率的关系,建立恢复期心率推测运动心率的方法。方法以60名男兵为对象,在功率自行车上进行不同强度（20、40、60、80、100、120、140、160、180 W）的运动,每一运动强度持续6 min;受试者佩戴心率带,实时监测运动中及恢复期的心率。结果（1）运动心率与恢复期10,20,30,40,50,60 s的心率均存在显著性差异（P＜0．05）;（2）不同运动强度恢复期心率下降值的比较,20,40和60 W强度,80、100和120 W强度以及140、160和180 W强度3段各自比较均无显著差异;上述3段强度间相应恢复心率下降值比较有显著差异（P＜0．05）;（3）相同运动强度下不同时间（10、20和30 s）的单位时间恢复期心率下降值比较,0～10 s与10～20 s和20～30 s有显著差异（P＜0．05）,10～20 s和20～30 s无显著差异;（4）针对20～60 W、80～120 W、140～180 W 3段运动强度的运动心率和恢复期10～30 s时的恢复心率,回归分析得到运动心率与恢复期心率和恢复时间的回归方程。结论不同运动强度的恢复期心率随时间的变化规律存在异同;可依不同强度的运动心率推测方程,由恢复期心率和时间推测运动心率;恢复期心率和恢复时间的最佳测量时间是运动结束后10～30 s。     

运动强度和时间对左右心室影响的比较研究

目的:研究运动强度和时间对左右心室结构、功能和纤维化的影响及它们之间的异同,并初步探讨涉及的可能机理。方法:48只雄性SD大鼠,随机分为对照(Sed)组、中强度运动(ME)组和大强度运动(IE)组,每组又分为8周组和16周组,共6组,每组8只。对照组自由活动,中强度组和大强度组分别以速度15.2 m/min、坡度5°和速度28 m/min、坡度10°的条件每天运动1小时,每周运动5天。最后一次运动后,24小时内记录体重后使用心脏超声检测两心室的舒张末期内径和舒张末期室壁厚度及射血分数。采血后处死,迅速分离心脏。使用Elisa法检测大鼠血清cTnI浓度,天狼星红染色测定两心室的胶原容积分数。结果:在8周和16周时,中强度组和大强度运动组大鼠两心室舒张末期内径都大于对照组。仅16周时大强度组左心室舒张末期内径大于中强度组,其它中强度组和大强度组间左心室或右心室舒张末期内径无差异。随着运动强度增加和运动时间的推移,左心室及右心室舒张末期室壁厚度都有增加的趋势,但无统计学意义。大强度运动8周后,大鼠两心室的射血分数都有低于对照组和中强度组的趋势,但无统计学意义;而大强度运动16周后,两心室射血分数显著低于对照组和中强度组。大强度运动8周或16周后,血清cTnI显著高于对照组和中强度组,中强度组与对照组无差异。16周中强度组或大强度组两个心室的胶原容积分数大于8周时相应的组。8周或16周大强度运动组的右心室胶原容积分数显著大于相应的对照组,且16周时大强度组右心室胶原容积分数显著大于中强度组;而左心室相应的比较无差异。大鼠血清cTnI浓度与左心室和右心室收缩功能均负相关(r=-0.327,P=0.029和r=-0.582,P=0.000);大鼠血清cTnI浓度与左心室胶原容积分数不相关(P=0.276),但与右心室胶原容积分数中度正相关(r=0.597,P=0.000)。结论:1)16周中强度或大强度运动可导致左心室扩张,且运动强度越大扩张程度越大;而右心室扩张只需要8周中强度或大强度运动,但运动强度对右心室扩张程度的影响不明显。2)长期(8周或16周)耐力运动(中强度或大强度)使两心室壁有变肥厚的趋势。左心室肥厚和扩张可能不是同步的:先肥厚再扩张;但右心室肥厚和扩张是同步的。3)大强度耐力运动引起两心室收缩功能短暂性下降与心室损伤有关,且右心室可能比左心室损伤更严重。中强度运动不会引起心室损伤,对心室射血分数影响不大或无影响。4)长期(8周或16周)大强度耐力运动导致右心室胶原容积分数增加,可能是右心室损伤后形成的心肌纤维化,但左心室未见;而16周时中强度组和大强度组两心室的胶原容积分数分别大于8周时对应的组别,可能是8周之后的运动使两心室的心肌细胞继续肥大,细胞外基质也相应增多,并不是纤维化。     

不同海拔高原运动心率上限值的探讨

目的 分析不同海拔高原递增负荷运动心率的变化特征,探讨高原运动心率是否存在150次/min上限值.方法 以不同海拔高原(3000 m,30人;3700 m,30人;4300 m,28人)驻防男性青年军人为研究对象,进行功率自行车阶梯负荷踏车运动,从30 W开始,每5 min增加30 W,直至不能坚持;采用Polar V...     

精神疲劳与运动疲劳状态下心率变异性的不同特征(英文)

目的以心率(HR)与心率变异性(HRV)作为应激水平的评价指标,分别探讨精神疲劳与运动疲劳时应激水平的变化规律。方法基于读书任务和笔算作业,研究精神疲劳时HR与HRV的变化;基于上肢力竭型运动,研究运动疲劳时HR的变化。结果高强度精神负荷过程中,受试者在实验伊始就达到了较高的应激水平,随着精神疲劳程度的增加,HR减小而HRV增大,表明精神疲劳程度与应激水平反相关,可能与生理抑制性保护有关;随着运动疲劳程度的增加,HR增加,表明运动疲劳程度与运动应激水平通常正相关,体现了机体的补偿性调整。结论精神疲劳与运动疲劳过程中,自主神经系统的活动存在较大差异,这可以从精神应激与运动应激的机理、主要承载器官和负荷强度的差别来解释。     

网球模拟比赛中运动强度与发球技术发挥的相关性分析

目的:通过网球模拟比赛中的运动强度(心率百分比)和技术发挥统计,分析运动员的运动强度与发球技术发挥的规律,为运动员自我调控比赛战术以及网球技战术训练提供科学依据。方法:选取8名一级水平网球运动员,将受试者随机配对,并采用ATP赛制。运用Polar心率表监控比赛中心率变化,固定索尼摄像机录制全场比赛,用雷达测速仪测发球球速,对数据进行统计分析。结果:(1)运动员整场比赛平均运动强度(MHR%)与一发失误率(1st SEr)的相关系数为0.588(P<0.05),与一发成功率(1stSSr)的相关系数为-0.644(P<0.01),与二发成功率(2nd SSR)的相关系数为-0.549(P<0.05);(2)在不同的比赛平均运动强度(MHR%)情况下,运动员前后两盘的一发成功率具有非常显著性差异(P<0.01),而运动员前后两盘的直接得分(Ace)次数、非迫性失误(Uf E)次数、二发成功率(2nd SSr)和一发平均球速(1st Savg S)呈显著性差异(P<0.05);(3)比赛中运动员区间三(最大心率的71%~75%)的一发成功率非常显著高于其他4个区间,区间四(最大心率的76%~80%)的一发成功率明显高于区间一、二和五;区间四(最大心率的76%~80%)的失误率明显高于其他4个区间;区间三(最大心率的71%~75%)的球速明显快于区间二(最大心率的66%~70%)。结论:(1)网球比赛中运动员的发球成功率与运动强度呈负相关。(2)网球比赛中运动员的体能下降显著影响发球质量和得分能力。(3)比赛过程中,网球运动员在最大心率的71%~75%心率区间,一发效果最好。     

老年人进行推拿功法易筋经不同呼吸次数锻炼的运动强度研究

目的:对老年人进行推拿功法易筋经不同呼吸次数锻炼的运动强度进行量化。方法:90名老年人随机分成三组,培训2个月后分别以推拿功法易筋经锻炼中定势站桩时长呼吸7次、9次和11次进行锻炼1个月,测试并比较各组锻炼前后及组间心率以及自觉运动强度分级(rate of perceived exertion,RPE),分析各组锻炼后目标心率(target heart rate,THR)。结果:①三组锻炼后心率均增加,组内前后差异显著(P<0.05)。②锻炼后,站桩定势呼吸7次组平均心率低于呼吸9次组和11次组,有统计学意义(P<0.05),呼吸9次组和11次组心率比较无显著性差异(P>0.05)。③呼吸7次组锻炼后达到目标心率的人数少于呼吸9次组和11次组,有统计学意义(P<0.05),呼吸9次组和11次组比较无显著性差异(P>0.05)。④自觉运动强度分级比较,随着站桩定势呼吸次数的增加,强度分级也逐步增加,三组之间有显著性差异(P<0.05)。自觉运动强度等级12～13级人数构成比,呼吸9次组多于呼吸7次组和11次组,有显著性差异(P<0.05)。结论:三种锻炼方式的运动强度不同,其差异由定势站桩时长(呼吸7次、9次、11次)不同导致,其中每一站桩定势动作持续呼吸9次、锻炼时间约18分钟,可以达到一定的锻炼强度。     

餐后不同运动因素对健康成人血糖和胰岛素的影响

目的:探讨餐后不同运动强度、持续时间、起始时间对健康成人血糖及胰岛素的影响.方法:7名年轻健康、不经常运动、BMI均低于20的受试者,参加有间歇的4组运动及前后2组静息实验,采用正交设计实验,运动因素为运动强度(3METs、5METs)、持续时间(15min、35min)、餐后运动起始时间(15min、30min),各因素分为两水平.检测空腹及服用标准餐后7个不同时间点(餐后15min、30min、45min、60min、90min、120min、150min)的血糖及胰岛素,计算血糖一时间曲线下面积(GAUC)和胰岛素一时间曲线下面积(IAUC),并监测运动能量消耗.结果:运动35分钟的餐后IAUC显著低于运动15分钟(P＜0.05);餐后起始运动时间为15分钟的GAUC及血糖峰值显著低于静息组(P＜0.05);不同运动强度间未见效果差异.持续35分钟运动的能量消耗显著高于持续15分钟;餐后15分钟开始运动的能量消耗显著高于30分钟,5METs强度运动的能量消耗显著高于3METs.结论:餐后持续运动35分钟较运动15分钟可显著改善餐后糖代谢;餐后15分钟开始运动产生的降低血糖峰值的效应优于餐后30分钟开始运动.     

药物对高原人体运动时心率的影响

目的 探讨在高原低氧条件下药物对人体运动心率(HR)的影响。方法 对进驻海拔4 100 m20 d的50名健康青年随机分为服用复方红景天组、西氏胶囊组、乙酰唑胺组、吸入一氧化氮(NO)组和对照组,每组10人。在服(吸入)6 d前后的安静时、踏阶运动5min及恢复5 min时分别检测HR。结果 服药前运动5 min及恢复5 min时5组HR较安静时增高非常明显(P<0.01);服药后安静时较服药前安静时HR4组服药组降低非常显著(P<0.01);服药后运动5 min时较服药前运动5 min时HR4组服药组降低显著(P<0.05);服药后恢复5min较服药前恢复5min HR西氏胶囊组及乙酰唑胺组降低显著(P<0.05),红景天组及NO组降低非常显著(P<0.01);服药后安静时HR4组服药组较对照组降低显著(P<0.05)服药后恢复5 min时HR红景天组及NO组较对照组降低显著(P<0.05)。结论 服用红景天、西氏胶囊、乙酰唑胺及吸入NO均能有效地提高和改善低氧条件下人体运动耐力和降低HR;吸入NO和服用红景天效果更明显。     

中国不同项目优秀运动员安静心率研究

目的:对我国930名优秀运动员的基础心率进行调查,从整体、项群和项目等不同层面比较分析我国优秀运动员的心率储备情况。结果发现,我国优秀男运动员安静心率平均58·95次/分,女运动员59·02次/分。男、女运动员最低心率均为37·00次/分。我国优秀运动员安静心率在各运动项群之间存在明显差异,快速力量项群运动员安静心率最快(男子66·23次/分;女子66·50次/分);速度耐力性项群,格斗对抗性项群,同场对抗性项群安静心率较低,并与快速力量项群存在显著性差异。我国优秀运动员整体窦性心动过缓发生率为55·29%。其中,同场对抗项群运动员窦性心动过缓发生率最高,达65·28%,其他依次为格斗对抗、速度耐力、表现难美、隔网对抗项群。快速力量项群运动员心动过缓发生率最低,仅为20·00%,显著低于其他项群(P<0·01)。本调查涉及的部分项目中,花样滑冰运动员心动过缓发生率最高(91·67%),其他依次为现代五项、散打、柔道、曲棍球、赛艇、皮划艇、足球、击剑、摔跤、排球、篮球、自行车、跳水、跳跃、羽毛球、网球和短道速滑,举重项目运动员心动过缓发生率最低(16·22%)。结果提示,长期运动训练可使优秀运动员的心率储备增加,安静状态下呈能量节省化状态;不同的项群项目特征以及运动员身体机能代谢对长期系统专项训练的适应性。     

非稳定周期轨道在立位心率变异分析中的应用

目的 研究立位心脏R－R间期信号的非稳定周期轨道的结构，进一步探讨心率变异（HRV）的动力学特征。方法 记录8名受试者平卧位5min和立位20min过程中的心电图，检测HRV信号的非稳定周期轨道。结果 立位时高周期数（周期2和周期3）的非稳定周期轨道出现率降低，HRV吸引子变得相对简单；非稳定周期1轨道位置随着体位和时间的改变而改变1。说明HRV的动力学特征有改变，心血管系统的调节功能有改变。结论：非稳定周期轨道可以刻划HRV的动力学性质，是分析HRV的潜在的方法。     

The use of heart rate variability measures to assess autonomic control during exercise

Heart rate variability (HRV) is a non-invasive indicator of cardiac autonomic modulation at rest. During rhythmic exercise, global HRV decreases as a function of exercise intensity. Measures reflecting sympathovagal interactions at rest do not behave as expected during exercise. This makes interpretation of HRV measures difficult, especially at higher exercise intensities. This problem is further confounded by the occurrence of non-neural oscillations in the high-frequency band due to increased respiratory effort. Alternative data treatments, such as coarse graining spectral analysis (CGSA), have demonstrated expected changes in autonomic function during exercise with some success. The separation of harmonic from fractal and/or chaotic components of HRV and study of the latter during exercise have provided further insight into cardioregulatory control. However, more research is needed. Some cross-sectional differences between HRV in athletes and controls during exercise are evident and data suggest longitudinal changes may be possible. Standard spectral HRV analysis should not be applied to exercise conditions. The use of CGSA and non-linear analyses show much promise in this area. Until further validation of these measures is carried out and clarification of the physiological meaning of such measures occurs, HRV data regarding altered autonomic control during exercise should be treated with caution.     

Oral magnesium therapy, exercise heart rate, exercise tolerance, and myocardial function in coronary artery disease patients

Background

Previous studies have demonstrated that in patients with coronary artery disease (CAD) upward deflection of the heart rate (HR) performance curve can be observed and that this upward deflection and the degree of the deflection are correlated with a diminished stress dependent left ventricular function. Magnesium supplementation improves endothelial function, exercise tolerance, and exercise induced chest pain in patients with CAD.

Purpose

We studied the effects of oral magnesium therapy on exercise dependent HR as related to exercise tolerance and resting myocardial function in patients with CAD.

Methods

In a double blind controlled trial, 53 male patients with stable CAD were randomised to either oral magnesium 15 mmol twice daily (n = 28, age 61±9 years, height 171±7 cm, body weight 79±10 kg, previous myocardial infarction, n = 7) or placebo (n = 25, age 58±10 years, height 172±6 cm, body weight 79±10 kg, previous myocardial infarction, n = 6) for 6 months. Maximal oxygen uptake (VO_2max), the degree and direction of the deflection of the HR performance curve described as factor k<0 (upward deflection), and the left ventricular ejection fraction (LVEF) were the outcomes measured.

Results

Magnesium therapy for 6 months significantly increased intracellular magnesium levels (32.7±2.5 v 35.6±2.1 mEq/l, p<0.001) compared to placebo (33.1±3.1.9 v 33.8±2.0 mEq/l, NS), VO_2max (28.3±6.2 v 30.6±7.1 ml/kg/min, p<0.001; 29.3±5.4 v 29.6±5.2 ml/kg/min, NS), factor k (−0.298±0.242 v −0.208±0.260, p<0.05; −0.269±0.336 v −0.272±0.335, NS), and LVEF (58±11 v 67±10%, p<0.001; 55±11 v 54±12%, NS).

Conclusion

The present study supports the intake of oral magnesium and its favourable effects on exercise tolerance and left ventricular function during rest and exercise in stable CAD patients.     

The effect of hypoxia and exercise on heart rate variability,immune response,and orthostatic stress

Hypoxia with exercise is commonly used to enhance physiological adaptation in athletes, but may prolong recovery between training bouts. To investigate this, heart rate variability (HRV), systemic immune response, and response to an orthostatic challenge were measured following exercise in hypoxia and air. Eleven trained men performed a 10‐km cycling time trial breathing hypoxia (16.5 ± 0.5% O₂) or air. HRV and the heart rate response to an orthostatic challenge were measured for 3 days before and after each trial, while venous blood samples were collected pre‐, 0, 2, and 24 h post‐exercise. Hypoxia had no significant effect compared with air. Subgroup analysis of those who had a drop in oxyhemoglobin saturation (SpO₂) > 10% between hypoxia and air compared with those who did not, demonstrated a significantly altered HRV response (△HFnu: ?2.1 ± 0.9 vs 8.6 ± 9.3, △LFnu: 2.1 ± 1.0 vs ?8.6 ± 9.4) at 24 h post‐exercise and increased circulating monocytes (1.3 ± 0.2 vs 0.8 ± 0.2 × 10⁹/L) immediately post‐hypoxic exercise. Exercise and hypoxia did not change HRV or the systemic immune response to exercise. However, those who had a greater desaturation during hypoxic exercise had an attenuate recovery 24 h post‐exercise and may be more susceptible to accumulating fatigue with subsequent training bouts.     

Rate of reduction of heart rate variability during exercise as an index of physical work capacity

Breathing rates during physical exercise suggest that, during these conditions, the high-frequency (HF) bandwidth of heart rate variability (HRV) analysis should be extended beyond conventional guidelines. However, there has been little investigation of the most appropriate choice of HF bandwidth during exercise. HRV analysis was performed in 10 males and six females during progressive bicycle exercise. Cardiac cycle (RR) interval and breath-by-breath respiratory data were simultaneously recorded. HRV powers were determined for the band-limited ranges 0.04-0.15 Hz [low-frequency (LF)], 0.15-0.4 Hz (HF 0.4) and 0.15-bf Hz (HF bf, where bf represents maximum breathing frequency). Mono-exponential functions described the relationship between HRV and work rate for each bandwidth (r=0.92-0.95) and were used to calculate the "HRV decay constant" (work rate associated with a 50% reduction in HRV power). The HRV decay constants for each bandwidth were linearly related to maximal work rate (r>0.71; P<0.001) and were substantially greater in males than in females (P<0.001). There was a significant difference between the HRV decay constants for HF 0.4 and HF bf (P<0.005) in both genders. The HRV decay constants for the LF and HF bf bandwidths appear to provide an indication of work capacity from submaximal exercise, without prior assumption regarding heart rate and its relationship with work rate.     

Effect of acute exercise-induced fatigue on maximal rate of heart rate increase during submaximal cycling

Different mathematical models were used to evaluate if the maximal rate of heart rate (HR) increase (rHRI) was related to reductions in exercise performance resulting from acute fatigue. Fourteen triathletes completed testing before and after a 2-h run. rHRI was assessed during 5 min of 100-W cycling and a sigmoidal (rHRI_sig) and exponential (rHRI_exp) model were applied. Exercise performance was assessed using a 5-min cycling time-trial. The run elicited reductions in time-trial performance (1.34 ± 0.19 to 1.25 ± 0.18 kJ · kg^?1, P < 0.001), rHRI_sig (2.25 ± 1.0 to 1.14 ± 0.7 beats · min^?1 · s^?1, P < 0.001) and rHRI_exp (3.79 ± 2.07 to 1.98 ± 1.05 beats · min^?1 · s^?1, P = 0.001), and increased pre-exercise HR (73.0 ± 8.4 to 90.5 ± 11.4 beats · min^?1, P < 0.001). Pre-post run difference in time-trial performance was related to difference in rHRI_sig (r = 0.58, P = 0.04 and r = 0.75, P = 0.003) but not rHRI_exp (r = ?0.04, P = 0.9 and r = 0.27, P = 0.4) when controlling for differences in pre-exercise and steady-state HR. rHRI_sig was reduced following acute exercise-induced fatigue, and correlated with difference in performance.     

健康成年人心率变异性分析285例

目的:为了解健康成年人心率变异性在人群中的变化规律.方法:采用Holter检测系统对285名健康成年人进行24 h动态心电图监测,然后分析时域法指标和频域法指标随年龄和性别不同的变化规律.结果:高年龄组的时域法指标和频域法指标显著低于低年龄组(P《0.05).各年龄组中女性的时域法指标均显著低于男性(P《0.05),而频域法指标在50岁以下各组女性显著低于男性(P《0.05),在50岁以上各组女性与男性没有显著性差别(P》0.05).结论:随着年龄的增长,心率变异性有下降的趋势,在青壮年男性的心率变异性高于女性.     

新战士运动应激时心理状态与心率和血压变化的关系

 目的 观测不同心理状态武警新战士运动应激时心率和血压的反应。方法 采用精神症状自评量表(SCL-90)对新战士进行集体心理状态测试,选取总分＞160分的40名战士纳入实验组(低心理素质组),另选取总分≤160分的40名战士作为对照组(高心理素质组)。采用GE-CASE活动平板运动测试系统,按照标准的Bruce方案测定两组战士在安静时、运动应激中每3 min和恢复阶段每1 min的心率和血压。结果 实验组达到极量运动的人数少于对照组,且出现不良反应如头晕、胸闷增多。实验组基础心率高于对照组(80.0±9.8)次/min vs (69.2±9.2)次/min,差异有统计学意义(P=0.023),极量运动时舒张压异常增高(96.6±6.4) mmHg vs (78.4±8.3) mmHg,差异有统计学意义(P=0.013),并伴有心率下降。恢复阶段,实验组心率恢复较慢。结论 不同心理状态的新战士在运动应激时出现的心血管系统反应存在显著差异,低心理素质组的战士不良反应较高心理素质组的战士增多,可能与其机体内各种应激激素分泌失衡有关。
     

Post-exercise heart rate variability of endurance athletes after different high-intensity exercise interventions

Methodological problems have limited the number of studies on heart rate variability (HRV) dynamics immediately after exercise. We used the short-time Fourier transform method to study immediate (5 min) and slow (30 min) recovery of HRV after different high-intensity exercise interventions. Eight male athletes performed two interval interventions at 85% and 93% (IV₈₅ and IV₉₃) and two continuous interventions at 80% and 85% (CO₈₀ and CO₈₅) of the velocity at VO_2max (vVO_2max). We found no increase in high frequency power (HFP), but low frequency (LFP) and total power (TP) increased ( P <0.05) during the first 5 min of the recovery after each intervention. During the 30-min recovery, HFP, LFP and TP (1) increased slowly toward resting values, but HFP remained lower ( P <0.01) than at rest, (2) were lower ( P <0.05) after IV₉₃ and CO₈₅ when compared with IV₈₅ and CO₈₀, respectively and (3) were lower ( P <0.01) after CO₈₅ when compared with IV₈₅. HRV recovery was detected during the immediate recovery after interventions. Increased exercise intensity resulted in lower HRV both in interval and in continuous interventions. In addition, when interval and continuous interventions were performed at a similar workload, HRV was lower after continuous intervention.     

武警新战士运动应激时心率和血压的变化

 目的 检测新入伍战士运动应激时心率和血压的反应.方法 采用活动平板运动试验,按照标准的Bruce方案从第3级开始对85名新入伍战士进行试验,测量休息时、运动应激中每3 min和恢复阶段每2 min的心率和血压.结果 运动应激开始后心率较安静时成倍增加,此后心率随着运动应激量的增加而增快,极量心率约为安静时的2.5倍,增加117次/min,期间有两个高峰,分别为运动至第5级和第7级时.恢复期心率以停止运动后2 min内减慢明显(减慢36次/min),10 min后恢复正常;运动应激时血压升高,以收缩压升高为主,应激过程中收缩压和舒张压分别约增加21 mmHg和4 mmHg,12 min后恢复至安静时水平,运动应激后舒张压持续降低.结论 运动应激时心率和收缩压的变化呈双峰型,心率恢复较血压快.