Effects of cigarette smoking on cardiac autonomic function during dynamic exercise

The purpose of this study was to investigate the acute effect of cigarette smoking on cardiac autonomic function in young adult smokers during dynamic exercise. Fourteen healthy young smokers (21.4 ± 3.4 years) performed peak and submaximal exercise protocols under control and smoking conditions. Resting and submaximal beat-to-beat R-R series were recorded and spectrally decomposed using the fast Fourier transformation. Smoking resulted in a significant decrease in work time, VO(2peak) and peak O(2) pulse (P < 0.05). Heart rate increased at rest and during submaximal exercise after smoking (P < 0.05). The raw high frequency and low frequency power were significantly reduced by smoking, both at rest and during exercise (P < 0.05). The low to high frequency ratio was higher after smoking (P < 0.05). The normalised low frequency power was also significantly increased by smoking, but only at rest (P < 0.05). These data demonstrate that the tachycardic effect elicited by smoking is accompanied by acute changes in heart rate spectral components both at rest and during exercise. Therefore, the cardiac autonomic control is altered by smoking not only at rest, but also during exercise, resulting in reduced vagal modulation and increased sympathetic dominance.     

A shorter set reduces the loss of cardiac autonomic and baroreflex control after resistance exercise

Set configuration may affect the recovery pattern of cardiac vagal autonomic and reflex modulation after a resistance exercise, since it is closely associated with intensity and volume and determines the metabolic involvement of the session. We tested the hypothesis that longer set configurations have a higher impact on cardiac autonomic control and baroreflex sensitivity compared with shorter set configurations. We studied the effects of three set configurations with the same components of work on the cardiac autonomic control and baroreflex sensitivity. Seventeen subjects performed one control session and three experimental sessions of a leg-press exercise with the same volume (40 repetitions), resting time (720?s) and intensity (10RM load): (a) 5 sets of 8 repetitions with 3?min of rest between sets (8S), (b) 10 sets of 4 repetitions with 80?s of rest between sets (4S) and (c) 40 sets of 1 repetition with 18.5?s of rest between each repetition (1S). Longer set configurations (8S and 4S) induced greater reductions of the vagal cardiac autonomic control and baroreflex sensitivity (p?≤?.001) compared with a shorter set configuration (1S). Also, 1S had non-significant reductions versus the control session (p?>?.05). These findings suggest that a shorter set configuration can reduce the impact of resistance exercise on the post-exercise cardiac vagal autonomic control and baroreflex sensitivity.     

有氧运动对大鼠心血管自主神经调节功能的影响

首先对心率变异性（HRV）和动脉压力反射敏感性（BRS）的测试分析方法进行了选取和改进,然后以正常大鼠为实验对象,观察比较尾动脉血压、脉搏、左室内压、心肌收缩力、心率变异性、动脉压力反射敏感性等指标在8周中等强度游泳运动组大鼠和和安静对照组大鼠之间的差异,旨在分析长期参加有氧运动对心血管自主神经调节功能的影响,为心血管自主神经平衡状态发生改变提供实验证据。研究发现,与对照组大鼠相比,运动组大鼠心肌出现肥大、心脏泵血功能增强、心交感神经介导的动脉压力反射敏感性升高、心迷走神经介导的动脉压力反射敏感性未受影响、心交感神经紧张性变异和心迷走神经紧张性变异程度均增加。研究结果提示,长期有氧运动可增强心血管自主神经的调节功能,使交感神经和副交感神经的协调与对抗关系在一个更高的功能层面上建立新的平衡。     

广播体操锻炼对女大学生心脏自主神经调节功能影响的实验研究

目的:采用HRV时域和频域分析指标对第八套广播体操锻炼对心脏自主神经的调节作用进行新的评价。方法:选取女大学生志愿者34名作为受试对象,随机分为三组:对照组(n=12)、实验一组(n=11)及实验二组(n=11)。实验一组和实验二组进行为期8周的第八套广播体操锻炼(每周5天,每天1次,其中实验一组每次连续做2遍广播操,实验二组每次做4遍),对照组不进行任何相关锻炼。用polar心率表(S810i,芬兰)记录了做广播操前、中、后即刻、后5分钟的心率及锻炼开始前、锻炼4周后、锻炼8周后安静状态下的心率,并采用专门软件对5分钟间期的心率变异性进行时域和频域分析。结果:①做第八套广播体操运动时RMSSD和HFnorm较运动前呈显著性降低,运动后5分钟仍未恢复至正常水平。而SD和LFnorm较运动前呈显著性升高,运动后5分钟仍未恢复至正常水平。LF/HF运动中及运动后即刻均较运动前显著增加,运动后5分钟恢复。②无论是实验一组还是实验二组经过8周的广播体操锻炼,可使安静时SD均呈现显著降低。结论:广播体操锻炼时表现为心交感神经紧张性增强、迷走神经紧张性降低,总体效应可持续至运动后5分钟。8周广播体操锻炼可以显著降低安静状态下心交感神经的紧张度。     

有氧运动对糖尿病大鼠心脏自主神经病变的影响

目的:探讨有氧运动对糖尿病大鼠心脏自主神经病变的影响。方法:42只健康雄性SD大鼠随机分为对照组、糖尿病组、糖尿病+有氧运动组,腹腔内注射链脲佐菌素制备糖尿病大鼠模型。糖尿病成模16周后有氧运动组大鼠进行12周跑台运动。之后所有成活大鼠分别利用心率变异性评估大鼠的电生理特性,利用免疫组化和RT-PCR法检测左心室心肌胆碱乙酰基转移酶(ChAT,标记迷走神经)和酪氨酸羟化酶(TH,标记交感神经)阳性神经纤维及其相应的mRNA表达水平。结果:与对照组大鼠相比,糖尿病大鼠心肌ChAT和TH阳性神经纤维的密度及mRNA明显降低(P<0.01),SDNN、LF、HF等指标均降低,反映交感神经活性的LF/HF比例显著增加。有氧运动干预后糖尿病大鼠心肌内ChAT和TH阳性神经纤维的密度仍低于对照组,但显著高于单纯糖尿病组(P<0.05),且ChAT/TH神经纤维比例显著增加,LF/HF比例降低。结论:有氧运动可降低持续高血糖状态对大鼠心脏交感、迷走神经的损伤,增加迷走神经支配比例,恢复迷走神经与交感神经的平衡状态,从而显著改善糖尿病心脏自主神经病变。     

Cardiodynamicsgram: a novel tool for monitoring cardiac function in exercise training

This study evaluated the feasibility of cardiodynamicsgram (CDG) for monitoring the cardiac functions of athletes and exercisers. CDG could provide an effective, simple, and economical tool for exercise training. Seventeen middle-distance race athletes aged 14–28 years old were recruited. CDG tests and blood test including creatine kinase (CK), CK-MB isoenzyme, and high-sensitivity troponin I (hsTnI) were performed before a high-intensity prolonged training, as well as 2 and 14 h after training, respectively. The CDG test result was unsatisfactory when the CK test result was used as standard. However, the accuracy of CDG test was about 80% when CK-MB and hsTnI were used as standards. Thus, CDG offers a noninvasive, simple, and economical approach for monitoring the cardiac function of athletes and exercisers during exercise training. Nonetheless, the applicability of CDG needs further investigation.     

有氧健身操对增强中年女性心肺功能的作用

通过对80名中年女性实施12周有氧健身操练习，探讨有氧健身操对提高中年女性心肺功能的作用，结果发现有氧健身操可降低安静心率与血压，提高台阶实验指数，增加肺活量，是一种有效提高中年女性心肺功能的健身方法。     

穴位离子导入对皮艇运动员心肺功能的影响

采用RPE评分、运动成绩测试、心肺功能测试及心脏内分泌激素放射免疫法检测等方法对运动员心脏功能进行跟踪观察。结果表明：(1)穴位离子导入能明显改善运动员的主观感觉，提高专项成绩，改善心肺功能，降低无氧闲心率，提高有氧耐力，推迟心源性运动性疲劳的发生；(2)穴位离子导入可改善运动员心脏神经肽ET和CGRP的分泌，使之向更有利于适应运动负荷的方向发展。结论是：(1)心源性运动性疲劳的发生与多因素相关；(2)穴位离子导入能多环节、多层面地保护心肌和改善心脏功能，从而延缓疲劳产生和促进疲劳消除。     

力竭运动时普通成年人心血管机能变化及运动习惯的影响

为探讨30～69岁普通成年男女在运动至"力竭"时的心血管机能变化特征及运动习惯的影响,以795名30～69岁的普通成年男女为对象,测定了运动至"力竭"时的心率、血压等指标,分析了运动习惯对运动时心血管机能变化的影响。结果表明男性力竭时的收缩压上升较高,超过220mmHg者占1/3以上。结果还提示在相同负荷下无运动习惯者的心血管机能指标上升幅度比有运动习惯者大。     

Alterations in autonomic cardiac modulation in response to normobaric hypoxia

Purpose: The present study aimed to determine if autonomic cardiac modulation was influenced by acute exposure to normobaric hypoxia. Method: Ten healthy male lowland dwellers completed five block-randomised single-blinded, crossed-over acute exposures to a normobaric hypoxic environment, each separated by 24 hours’ recovery (20.3%, 17.4%, 14.5%, 12.0% and 9.8% F_IO₂). Supine recordings were made of arterial oxygen saturation and electrocardiogram (ECG). RR intervals from the ECG trace were analysed for time (SDNN, lnrMSSD), frequency (lnVLF, lnLF, lnHF, lnTP, LFnu, and HFnu), and nonlinear (DFA-α1 and SampEn) heart rate variability components. Results: A significant reduction in arterial SaO₂ occurred with reduced F_IO₂, along with a rise in heart rate (Cohen’s d?=?1.16, 95% Confidence Interval [2.64–6.46]), significant at 9.8% F_IO₂. A decrease in autonomic cardiac modulation was also found as shown by a statistically significant (at 9.8% F_IO₂) decrease in lnTP (d?=?1.84 [1.74–1.94]), and SampEn (d?=?0.98 [0.83–1.12]) and an increase in DFA-α₁ (d?=?0.72 [0.60–0.84]) from normoxia at 9.8% F_IO₂. Conclusion: The decrease in variability indicated a reduction in autonomic cardiac modulation. There appears to be a threshold ～9.8% F_IO₂ (～6000?m equiv.), below which significant alterations in autonomic control occur.     

运动时心肌的乳酸代谢

心肌摄取乳酸的多少与动脉乳酸浓度呈正相关。运动时,动脉乳酸浓度增加,心肌血流量增加,因而心肌摄取氧化乳酸增加;剧烈运动时,当血乳酸浓度大于3-4mM时,乳酸就可能成为心肌有氧代谢的重要产物。     

恒定负荷运动中和运动后左室舒张功能的变化

采用脉冲多谱勒超声心动图观察运动中和运动后左室舒张功能的变化。研究结果显示运动时随强度的增加舒张早期最大的峰值速度E峰峰值流速、舒张晚期最大的峰值速度A峰峰值流速，舒张早期最大瞬时压差(PPGE)、舒张末期最大瞬时压差(PPGA)增加，但vE／vA值下降。其动力来源可能与运动时左室的收缩功能提高有关。运动后恢复期E峰、A峰峰值流速，PPGE、PPGA逐渐减少，vE／vA值逐渐增大，并很快恢复到安静状态。     

膳食脂肪对运动能力的影响及运动时脂代谢的调节

就膳食脂肪对运动能力的影响以及脂肪代谢的调节作一综述。运动强度、时间不同，脂肪供能所占的比例不同，脂肪供能对运动成绩的影响也有所差异。运动时脂代谢的调节受多种因素的影响，激素敏感性甘油三酯脂肪酶(HSL)是酶解速度的主要控制因素。     

Effects of different types of exercise on muscle mass,strength, function and well-being in elderly

Abstract

Poor muscle strength and physical function have been associated with higher risk of hospitalisation and lower well-being among the elderly. Physical training increases muscle strength, endurance and physical function as well as psychological outcomes. Exercise among older adults is often used to improve these variables, but few have compared the effects of different types of training in parallel independent groups. Thus, the aim of the present study was to investigate the effect of three different types of training on body composition, muscle strength, physical function and well-being in the elderly. A total of 118 community-dwelling older adults (mean age 74.3, s=4.6 years, 68% women) completed a 13-week randomised controlled exercise-trial involving four groups: traditional strength training (STG), functional strength training (FTG), endurance training (ETG) and control (CON). Stair climb with load improved more in FTG than CON (P<0.05), and the two strength groups performed better in the functional upper body test (P<0.05). STG increased strength more than CON in all exercises (P<0.001), while FTG increased strength more than CON in the chest press, shoulder press and knee extension (P<0.05). Lean body mass (LBM) increased in all training groups, which differed significantly from CON (P<0.05). ETG decreased their fat mass compared to CON (P<0.001). The only significant effect on well-being indices was improved life satisfaction in FTG at week 5 (P<0.05). We also observed significant correlations between change in some of the functional tests and change in positive affect.

All three types of training can enhance physical capacity. Functional strength training can be a cost effective form of training in terms of less demand for instructors and equipment and could be an effective way to improve physical function, strength and indices of well-being in the elderly.     

大强度运动对免疫功能的影响及其可能机制

目的：跟踪和展望大强度运动对免疫功能的影响及预防运动后免疫功能下降,保证运动员的身体机能良好并且更好地进行运动训练。方法：采用回顾性研究和前瞻性分析相结合的综述性研究方法,阐述了运动对免疫功能的影响及其可能机制、大强度运动对免疫功能抑制机制。结论：大强度运动后,机体的免疫功能会发生明显的变化,淋巴细胞及其亚群浓度下降,增值分化能力和活性降低,免疫球蛋白含量及功能也受到影响,出现运动后抑制现象。长时间、大负荷训练可以导致机体细胞免疫功能的显著降低,使血清Gln、Arg含量的降低和外周淋巴细胞凋亡速率增快,可能是运动性免疫抑制的重要机制。     

Effects of short-term exercise training on tissue Doppler indices of left ventricular diastolic function in overweight and obese individuals

Abstract

Although exercise training is unable to improve obesity-associated decreases in left ventricular (LV) diastolic function, as assessed using chamber function measurements, the effects on LV diastolic myocardial function, as assessed using tissue Doppler imaging (TDI), are uncertain. In 32 overweight (n = 11) or obese (n = 21), sedentary or recreationally active men and women (30–57 years), we assessed the effects of 6 weeks of exercise training either preceded (n = 16) or followed (n = 16) by a 6-week control period on TDI indices of LV diastolic function (e', e'/a' and E/e') (echocardiography). Diastolic function at baseline was comparable to that noted in overweight and obese participants from a community sample (n = 245), and 56% (n = 18) had e' values below the lower 95% CI of a lean and healthy cohort (n = 60) of the community sample. Exercise training increased peak oxygen consumption (27.4 ± 4.9 to 29.4 ± 5.8 mL · kg^–1 · min^–1, P = 0.0001), but had no effect on body mass index (P = 0.99). No changes in TDI indices of diastolic function were observed after exercise training in all the participants (e': P = 0.74, a': P = 0.98, e'/a': P = 0.85, E/e': P = 0.26), participants with abnormal e' values (n = 18)(e': P = 0.99, a': P = 0.96, e'/a': P = 0.91, E/e': P = 0.97) or obese participants (n = 21)(e': P = 0.67, a': P = 1.00, e'/a': P = 0.78, E/e': P = 0.11). In conclusion, exercise training, despite increasing cardiorespiratory fitness, is unable to improve obesity-associated decreases in LV diastolic myocardial function.     

康复运动处方对青少年支气管哮喘患者呼吸机能的影响

观察康复运动处方对青少年支气管哮喘患者呼吸机能的影响。支气管哮喘患者31例，随机分成A、B两组，A组11例维持已有的药物治疗；B组20例在已有药物治疗基础上实施康复运动处方。两组的观察时间均为12周，对所有患者试验前后的哮喘症状、肺功能及不良反应进行了随访观察和测定。结果：肺活量、肺功能FEV1、PEF明显改善，提示哮喘症状呈逐步稳定状态。喘息、痰量、哮呜音症状改善有效率分别为A组63．64％、45．45％、54．56％；B组85％、75％、80％。试验所取得的正向效果。证明了康复运动处方对改善和提高青少年支气管哮喘患者的呼吸机能有显著效果．     

Reliability of a combined biomechanical and surface electromyographical analysis system during dynamic barbell squat exercise

Abstract

An analysis system for barbell weightlifting exercises is proposed to record reliable performance and neuromuscular responses. The system consists of surface electromyography (sEMG) synchronized with electrogoniometry and a barbell position transducer. The purpose of this study was to establish the reliability of the three components of the system. Nine males (age 28.9 ± 4.8 years, mass 85.7 ± 15.1 kg) performed squat exercise at three loads on three separate trial days. A data acquisition and software system processed maximal knee angle (flexion), mean power for the concentric phase of squat exercise, and normalized root mean square of the vastus lateralis. Inter-trial coefficients of variation for each variable were calculated as 5.3%, 7.8%, and 7.5% respectively. In addition, knee joint motion and barbell displacement were significantly related to each other (bar displacement (m) = 1.39–0.0057 × knee angle (degress), with goodness-of-fit value, r ² = 0.817), suggesting knee goniometry alone can represent the kinematics of a multi-joint squat exercise. The proven reliability of the three components of this system allows for real-time monitoring of resistance exercise using the preferred training methods of athletes, which could be valuable in the understanding of the neuromuscular response of elite strength training methods.     

炙甘草汤对反复力竭运动大鼠心肌保护作用的研究

目的:探讨中药方剂炙甘草汤对反复力竭运动大鼠心肌的保护作用.方法:Wistar雄性大鼠60只,随机分成3组:对照组(20只),运动组(20只),运动+中药组(20只).运动组和运动+中药组进行每周6天、每天1次的力竭游泳,共2周.运动前1小时,对照组和运动组灌胃给予2.5毫升蒸馏水,运动+中药组灌胃给予炙甘草汤药液2.5毫升(生药含量为20％).最后一次给药后,测定大鼠力竭性游泳持续时间.腹主动脉取血,分离血清测定cTnI,取心脏,测定心肌SOD活性和MDA含量.结果:1)与运动组相比,运动+中药组的游泳持续时间显著增加;2)与对照组相比,其它两组cTnI均显著性升高;与运动组相比,运动+中药组cTnI显著性降低;3)与对照组相比,运动组SOD活性显著降低;与运动组相比,运动+中药组心肌的SOD活性显著升高;4)与对照组相比,运动组MDA含量显著升高;与运动组相比,运动+中药组大鼠心肌的MDA含量显著降低.结论:炙甘草汤能显著降低反复力竭运动大鼠心肌MDA水平,增加SOD活性,显著降低血清cTnI水平,延长大鼠力竭游泳持续时间,说明本中药方剂能降低反复力竭运动对心肌的损伤,从而提高运动耐力.     

急性运动对人体细胞免疫功能的影响

为探索运动对细胞免疫功能的影响，检测了7名男运动员一次急性疲劳性运动前和运动后即刻、3h、24h的外周血TLT、IH活性和皮质醇及胰岛素浓度的变化。结果：在运动后即刻，TLT显著增强，IL—2活性和血浆皮质醇浓度分别略有上升和下降；在运动后3h，前2项指标和血浆皮质醇浓度分别明显增强和降低。这3项指标在运动后24h均恢复到运动前水平。IL-2活性变化与皮质醇变化有显著负相关关系。胰岛素在运动前后无明显变化。结果表明：一次急性适度运动可提高人体的细胞免疫功能，并可持续数小时。这种变化与血浆皮质醇浓度下降有一定关系。