心阻抗技术在心脏外科监护中应用价值的研究

心阻抗图是目前正在发展的非侵入性心血管功能监测技术之一。本研究报告58例心脏直视手术病例,术前和术后应用心阻抗图进行了心血管功能监测。结果发现,所监测心脏指数(CI)的结果和变化规律同其他作者用染料法测定者基本一致。射血速度指数(EVI)>1.0Ω/s时,表示心脏功能正常,EVI<0.8Ω/s时,说明心脏功能低下,EVI用于判断心肌功能较为敏感和可靠。胸液指数(TFI)<1.9Ω时常伴有动脉血气异常。研究证明,心阻抗技术对于心脏外科病人术后监护具有较大的参考价值,并且具有连续、非侵入性和实时监测的特点。     

三周间断性短臂离心机+Gz暴露和运动负荷对人体心功能的影响

目的 利用短臂离心机进行梯度G值暴露联合运动负荷锻炼,观察间断性锻炼3周后人体心脏收缩、泵血功能的变化.方法 8名健康青年男性间断进行梯度G值(1-2 G)离心机+Gz暴露联合30 W运动负荷锻炼,每天30 min,持续3周.采用心电机械图法和阻抗法测量锻炼前后心脏的收缩功能与泵血功能.结果 锻炼2周后被试者左室射血时间(LVET)及射血分数(EF)较锻炼前显著增加(P<0.05).心率(HR)、射血前期(PEP)与LVET比值(PEP/LVET)显著下降(P<0.05);锻炼3周后,LVET及EF进一步增加(P<0.01),HR及PEP/LVET进一步下降(P<0.05),同时PEP下降达到差异显著性,每搏量(SV)和总外周阻力(TPR)显著增加(P<0.05).结论 3周间断性离心机+Gz暴露联合运动负荷锻炼可显著增强心脏收缩与泵血功能.     

连续4个周期旋梯训练对飞行学员心功能的影响研究

目的观察利用旋梯进行梯度抗载荷训练连续锻炼4个周期(14d为1个周期)后,飞行学员心脏收缩、泵血功能的变化。方法10名飞行学员进行梯度抗载荷训练连续4个周期,梯度Gz值为3G→1G→3G→1G,每梯度Gz值持续30s,实验期间训练1d休息1d,每次训练30min。采用心电机械图法和阻抗法测量锻炼前及每个周期结束后心脏收缩功能与泵血功能。结果训练2个周期后受试者左室射血时间(LVET)较训练前显著增加(P0.05);3个周期后射血分数(EF)较训练前显著增加(P0.05),4个周期后结果与第3周期结果基本相同。训练2个周期后受试者射血前期(PEP)及心率(HR)较训练前显著下降(P0.05),第3、4周期结果与第2周期基本相同。受试者PEP与LVET比值(PEP/LVET)在第3个周期后较训练前显著下降(P0.05),每搏输出量(SV)显著增加(P0.05),实验期间受试者总外周阻力(TPR)及心输出量(CO)无显著变化。结论 4个连续周期旋梯训练可显著增强心脏收缩与泵血功能。     

踝泵运动联合抗阻运动在老年糖尿病足患者康复中的应用效果分析

目的 探讨踝泵运动联合抗阻运动在老年糖尿病足患者康复中的应用效果。方法 选取2020年10月至2022年10月商丘市中医院收治的66例老年糖尿病足患者作为研究对象,按照不同治疗方法将其分为观察组(33例)与对照组(33例),观察组患者采用踝泵运动联合抗阻运动进行干预,对照组患者单纯采用抗阻运动进行干预,对比观察两组患者创面面积、踝肱指数(ABI)及足背动脉血流速度。结果 干预1个月后,观察组患者创面面积为(3.45±1.32) cm²,明显小于对照组患者的创面面积(5.98±1.41) cm²(t=7.525,P<0.001);观察组患者ABI为(1.18±0.12),明显大于对照组患者的ABI (0.93±0.11)(t=8.963,P<0.001);观察组患者足背动脉血流速度为(7.63±0.75) cm/s,明显快于对照组患者的足背动脉血流速度(6.38±0.42) cm/s (t=8.544,P<0.001)。结论 与单纯应用抗阻运动相比,踝泵运动联合抗阻运动可明显改善老年糖尿病足患者的ABI,提高足背动脉血流速度,...     

茜草提取物对大强度耐力训练大鼠不同组织NO-NOS体系及运动能力的影响

目的:探讨茜草提取物对大强度耐力训练大鼠不同组织NO-NOS体系酶活性及运动能力的影响。方法:24只SD大鼠随机分安静对照组、运动对照组和运动+茜草组,每组8只。运动对照组进行6周大强度跑台训练,同时运动+茜草组每天灌胃2ml剂量为0.5g/kg的茜草生理盐水溶液,安静组和训练组灌胃同体积的生理盐水。在最后一周结束后,安静组在安静时、运动对照组和运动+茜草组进行一次力竭性运动后取材,测定血清和不同组织一氧化氮(NO)含量和结构型一氧化氮合酶(cNOS)、诱导型一氧化氮合酶(iNOS)、总NOS活性。结果:运动+茜草组大鼠力竭运动时间(96.76±18.78min)显著长于运动对照组(78.95±25.47min)(P<0.05)。力竭运动后,运动对照组和运动+茜草组大鼠各组织(心脏、肝脏、脑、肾脏、股四头肌)和血清NO含量均显著高于安静对照组(P<0.01),运动+茜草组大鼠血清、心脏、脑、肾脏、股四头肌NO含量显著高于运动对照组(P<0.01,P<0.05);运动对照组大鼠心脏、肝脏、股四头肌、脑、肾脏cNOS和总NOS活性均显著低于安静对照组(P<0.05,P<0.01),iNOS活性均显著高于安静对照组(P<0.05,P<0.01);运动+茜草组大鼠心脏、肝脏、股四头肌、脑、肾脏cNOS活性显著高于运动对照组(P<0.01,P<0.05),心脏、肝脏、肾脏iNOS活性显著低于运动对照组(P<0.05),肝脏、脑、股四头肌总NOS活性显著高于运动对照组(P<0.05)。结果表明,补充茜草提取物可以调节大鼠不同组织中NOS活性,增加NO含量。     

短臂离心机重力暴露及有氧运动对心血管功能的影响

目的 观察利用短臂离心机单纯人工重力暴露、单纯有氧运动锻炼、人工重力暴露联合有氧运动锻炼3种锻炼方案对心血管功能及心脏自主神经调节功能的影响.方法 将24名健康青年男性志愿者随机分为3组:单纯人工重力暴露组、单纯有氧运动锻炼组及人工重力暴露联合运动锻炼组,每组8人.单纯人工重力暴露组进行间断梯度G值(1～2 G)离心机锻炼,单纯有氧运动锻炼组进行40 W的有氧运动负荷锻炼,人工重力暴露联合有氧运动锻炼组则进行间断梯度G值(1～2 G)离心机暴露,同时进行40 W运动锻炼,每天30 min,持续1周.采集心电图和逐跳连续血压,分析心率变异性与收缩压变异性功率谱.采用心电机械图法和阻抗法测量锻炼前后心脏的收缩与泵血功能.结果 人工重力暴露联合有氧运动锻炼组1周后受试者心率较锻炼前显著下降,且有统计学意义(P＜0.05),每搏量、左室射血时间及血压变异性低频功率较锻炼前显著增加,且有统计学意义(P＜0.05),而其他两组以上参数无显著变化.结论 1周人工重力暴露联合40 W有氧运动负荷锻炼可显著增强心脏泵血功能及自主神经调节功能.上述参数的明显改善可能得益于人工重力与有氧运动的复合作用. Abstract： Objective To investigate the changes of cardiovascular function and cardiovascular autonomic nervous regulation caused by short arm centrifuge exposure (SAC), aerobic exercise (EX),or their combination (SAC+ EX).Methods Twenty-four healthy male subjects were randomly and averagely divided into 3 groups that executed SAC, EX and SAC+ EX respectively.Subjects in SAC group experienced 1-2 G centrifuge training while EX group merely performed aerobic exercise with 40 W-load.In SAC+ EX group, subjects performed 40 W-load exercise for 30 min when they exposed on centrifuge once a day for 1 week.Electrocardiogram, continue blood pressure were monitored and used for HR variation and systolic blood pressure variation spectrum a(n)alysis.The training caused changes on systole and blood-pumping functions were got by analyzing mechanical-cardiogram and impedance-cardiogram.Results Analysis showed that 1-week SAC+EX training improved subjects' cardiac pumping function and cardiovascular autonomic nervous modulation, which associated with significant decreased heart rate (P＜0.05) and significant increased stroke volume (SV), left ventricular ejection time (LVET) and lower frequency (0.04-0.15 Hz) of arterial pressure spectral power (P＜0.05) as compared with those in other 2 groups.Conclusions 1-week SAC+40 W-load EX training could significantly improve cardiac pumping function, cardiac vagal modulation and peripheral smooth muscle vascular tone.Such combined action promotes the changes.However,alternative SAC or EX training is not sufficient enough to induce similar alterations.     

耐力运动联合NAD合成酶基因CG9940过表达对中老龄果蝇心脏功能、运动能力和寿命的影响

目的:探讨耐力运动、NAD合成酶相关基因CG9940以及耐力运动联合CG9940基因过表达对中老龄果蝇心脏功能、运动能力和寿命的影响。方法:y[1]w[67c23]P{y[+m8]=Mae-UAS.6.11}CG9940[GG01267]雌性果蝇分别与W1118雄性果蝇、arm-Gal4雄性果蝇杂交取F1代分为对照组、运动组、过表达对照组和过表达运动组,4组均收集400只处女蝇,饲养至30天龄开始训练,连续训练5天,次日取材。实时荧光定量PCR测定CG9940基因m RNA表达量,M-mode心动图检测心管收缩时间、收缩直径、舒张直径、舒张功能不全指数、射血分数和心律失常指数,测量攀爬指数,统计生命周期。结果:(1)过表达对照组CG9940 m RNA过表达率为155.2%,过表达运动组的过表达率为152.0%。(2)与对照组相比,运动组心率降低(P<0.01),射血分数增大(P<0.01),舒张功能不全指数降低(P<0.05);过表达对照组心率降低(P<0.05),射血分数增大(P<0.01);过表达运动组心率降低(P<0.01),心脏平均收缩速度增大(P<0.05),射血分数增大(P<0.01),舒张功能不全指数减小(P<0.01),心律失常指数降低(P<0.05)。与运动组相比,过表达运动组心率降低(P<0.05),射血分数增大(P<0.01),舒张功能不全指数减小(P<0.05)。与过表达对照组相比,过表达运动组心率降低(P<0.05),射血分数增大(P<0.05),舒张功能不全指数减小(P<0.01)。(3)运动组攀爬指数高于对照组(P<0.05);过表达运动组攀爬指数高于对照组(P<0.01)和过表达对照组(P<0.05)。(4)运动组寿命高于对照组(P<0.05);过表达对照组寿命高于对照组(P<0.01);过表达运动组寿命高于对照组(P<0.01)、运动组(P<0.01)和过表达对照组(P<0.05)。结论:耐力运动能够提高中老年果蝇运动能力并且能延缓心脏功能性衰退和延长生命周期;NAD合成酶基因CG9940过表达能够延缓果蝇心脏衰老,显著延长果蝇寿命;耐力运动联合CG9940基因过表达能降低中老龄果蝇心律失常和舒张功能不全,同时能增强中老龄果蝇逆重力攀爬特征,提高活动能力,并且延寿效果更好,表明二者对中老龄果蝇抗衰老产生叠了加效应。     

有氧运动改善高脂膳食诱导的胰岛素抵抗:增强骨骼肌线粒体融合与分裂及功能

目的:研究高脂膳食诱导胰岛素抵抗(IR)发生中骨骼肌线粒体融合与分裂的改变和长期耐力训练对其影响,为深入探讨IR发生的分子病理学机制以及运动防治IR的机制提供依据。方法:雄性C57BL/6小鼠通过8周高脂膳食诱导IR,再分别将正常和IR小鼠分为安静组和运动组,即正常膳食对照组(NS)、正常膳食运动组(NE)、高脂膳食对照组(HS)、高脂膳食运动组(HE),各运动组进行8周有氧运动训练。检测空腹血糖、胰岛素。提取骨骼肌线粒体测定呼吸功能和ATP合成酶活力。实时荧光定量PCR和Western blot分别测定骨骼肌Mfn2、Opa1、Drp1、Fis1的mRNA和蛋白表达。结果:(1)HS组小鼠空腹血糖、胰岛素和胰岛素抵抗指数均显著高于NS组(P<0.01);骨骼肌线粒体态3呼吸速率、呼吸控制比和ATP酶合成活力均显著低于NS组(P<0.01);Mfn2蛋白显著低于NS组(P<0.01),Drp1和Fis1显著高于NS组(P<0.01)。(2)HE组小鼠空腹血糖、胰岛素和胰岛素抵抗指数均显著高于HS组(P<0.01);骨骼肌线粒体态3呼吸速率、RCR和ATP酶合成活力均显著高于HS组(P<0.01);Mfn2、Opa1和Drp1蛋白显著高于HS组(P<0.01,P<0.05,P<0.01)。结论:高脂膳食诱导IR的小鼠骨骼肌线粒体趋于分裂,呼吸功能和ATP合成能力下降,可能是高脂膳食诱导IR的机制之一。长期有氧运动训练使正常和IR小鼠骨骼肌线粒体融合和分裂均增强,促进线粒体呼吸功能和ATP合成能力,有利于预防和改善IR。     

不同湿度高温环境下机体有氧运动能力相关指标比较

目的:探讨不同湿度高温环境对有氧运动能力的影响。方法:随机选取10名男性大学生为对象,设定环境温度为33℃,相对湿度分别为20%、40%、60%、80%作为模型,实验时间4周,两次测试之间间隔1周。测试时受试者进行递增负荷跑台运动,以8 km/h为起始速度,每分钟增加0.8 km/h到16 km/h为止,然后逐级加坡度,0.5%为起始坡度,每分钟递增0.5%直至受试者不能坚持,运动过程中监测心率、摄氧量、每分钟通气量(VE)以及主观用力感觉指数(RPE),测试前及结束后无名指采血测试血乳酸。结果:不同湿度高温环境下运动VE、最大心率(HRmax)、最大摄氧量(VO2max)无显著性差异,60%相对湿度下运动时VO2max(3831.7±313.16 ml/min)、VE(137.5±9.38 L/min)、HRmax(199.1±8.29 beat/min)均较其余相对湿度大。20%相对湿度组运动后3 min及5 min血乳酸较80%湿度组显著升高(P<0.05),60%相对湿度组运动后3 min血乳酸亦显著高于80%湿度组(P<0.05)。80%相对湿度组运动后1 min RPE仍显著高于40%相对湿度组(P<0.05),20%相对湿度组RPE值增加较缓慢,运动至第7和10 min时RPE值显著低于60%相对湿度组(P<0.05)。结论:与其余湿度相比,33℃高温环境下,80%相对湿度中机体有氧运动能力并未得到充分发挥。     

有氧运动对单纯性肥胖小学生肺通气功能和心电图的影响

目的:探讨有氧运动对单纯性肥胖小学生肺通气功能和心电活动的影响。方法:选择10～11岁单纯性肥胖男生30人,进行12周有氧运动,每周4次,每次40min,并于实验前后对受试者身体成分、肺通气功能和心电图进行观察分析。结果:12周有氧运动后体脂肪量(FM)和体脂肪百分率(BF)均显著下降(P<0.05),去脂肪量(FFM)显著增加(P<0.05),腰/臀围比(WHR)有所下降但无统计学意义;肺通气功能指标中,每分最大通气量(MVV)、用力呼吸第一秒钟呼气量(FEV1)、50%肺活量时的单位身高呼气流速(V50/Ht)和单位身高呼气高峰流速(PEFR)等指标实验后明显升高,与实验前比较差异均有统计学意义(P<0.05,P<0.01);心电图指标中,与实验前比较,QT离散度(QTd)和校正QT离散度(QTcd)均显著减小(P<0.05,P<0.01)。结论:有氧运动可以改善肥胖小学生肺通气功能,对心电活动状态具有良性调节作用。     

运动疗法对冠心病患者PTCA及支架术后心功能和自主神经功能的影响

目的 :探讨运动疗法对冠心病患者PTCA或支架术后的心功能及自主神经功能的影响。方法 :对 37例PTCA或支架术后的患者进行运动心功能评定 ,制定康复运动处方 ,进行 8周康复运动训练 ,采用Bruce方案亚级量分级运动试验进行康复评定 ,采用心率变异 (HRV)对训练前后患者的自主神经功能进行评价。结果 :实施运动疗法后患者心率增值较 8周前明显增加 (P <0 0 1) ,血压 (包括收缩压和舒张压 )、心率 -血压乘积 (RPP)均比治疗前显著下降 (P <0 0 5或P <0 0 1) ,患者在运动实验中的运动时间延长、运动负荷增加 (P <0 0 1) ,运动诱发的最大ST段压低明显改善(P <0 0 1)。训练前患者时域和频域指标显著低于对照组 (P <0 0 1) ,训练后以上各项指标较康复训练前均有回升 (P <0 0 5或P <0 0 1)。结论 :康复运动训练能提高PTCA或支架术后冠心病患者的心功能 ,改善心脏自主神经功能。     

双侧颈深浅丛均阻滞对循环呼吸功能的影响

目的探讨应用浓度为0.67%利多卡因和0.25%左布比卡因合剂在双侧颈深浅丛均阻滞时,对呼吸及循环功能的影响。方法麻醉穿刺方法同传统的改良的一点深丛阻滞法。实验组为两侧深浅丛均阻滞,深丛注药4 ml;浅丛于胸锁乳突肌后缘,于皮肤与颈阔肌间向头、向足、向对侧各注药3ml,胸锁乳突肌中点处注药2 ml,共计30 ml;对照组为传统的改良阻滞法。分别记录阻滞前,阻滞后15、30、45、60 min和手术毕6个时间点的呼吸频率(RR)、血氧饱和度(SpO2),心率(HR)、收缩压(SBP)及舒张压(DBP)。结果两组患者呼吸循环功能在阻滞后的30min内,RR、SpO2,HR、SBP、DBP变化都较明显,两组比较差异有统计学意义(P<0.05或P<0.01)。结论小剂量、低浓度的利多卡因和左布比卡因合剂应用于双侧颈深浅丛均阻滞对呼吸循环影响更小,相对更安全。     

健步走和太极拳综合练习后非酒精性脂肪肝患者肝损伤及储备功能的变化

目的:探讨健步走和太极拳综合练习后非酒精性脂肪肝(NAFLD)患者肝损伤、储备功能及血脂的变化,分析有氧运动对NAFLD肝功能(肝损伤及储备功能)及血脂指标的影响差异。方法:随机抽取广州市番禺区自来水公司NAFLD患者24人(男性18人,女性6人),实施为期16周健步走和太极拳综合练习的有氧运动,每周4次,每次1小时。运动强度为60%～70%HRmax(HRmax=220-年龄),运动强度开始为50%～60%HRmax,逐步递增至60%～70%HRmax。分别于实验前和有氧运动16周后采用B超诊断受试者肝脏脂肪变性程度,测定受试者体重和BMI;于实验前、有氧运动8周后、16周后测定肝功能指标丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、谷氨酰转移酶(GGT)、碱性磷酸酶(ALP)、总蛋白(TP)、白蛋白(ALB)和血脂指标甘油三酯(TG)、胆固醇(TC)、载脂蛋白A-1(ApoA-1)、载脂蛋白B(ApoB)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)。结果:(1)16周有氧运动后,B超结果显示,NAFLD患者肝脏改善平均有效率为70.8%,其中轻度脂肪肝较重度脂肪肝有效率显著升高(P<0.05)。受试者体重和BMI显著降低(P<0.05或P<0.01)。(2)与实验前比较,16周有氧运动后患者血清GGT、ALT、AST、ALP显著下降,TP、ALB和ALB/GLB显著升高,有氧运动8周后GGT、ALB出现显著变化(P<0.05或P<0.01)。(3)与实验前比较,8周有氧运动后LDL-C、载脂蛋白与脂质比值均出现显著变化(P<0.05或P<0.01)。结论:16周健步走和太极拳综合练习能有效改善NAFLD患者肝损伤、储备功能及血脂代谢紊乱,而GGT和ALB与其它肝功能指标相比较先变化。LDL-C、载脂蛋白与血脂脂质比值结合,较单一指标能更好地监控有氧运动改善NAFLD脂代谢紊乱过程。     

冠心病康复治疗疗效观察

<正> 冠心病的康复治疗国内外均极为重视。早在一千六百多年前,晋代许逊首次记述了治疗心脏病的运动方法“心脏导引术”。他所记述的导引相当于现在的气功和医疗体操。国外在1772年Heberden曾报道一例冠心病人经过六个月的锯木运动后获得“基本治愈”。本世纪七十年代以来,由于临床诊治     

Neutrophil function response to aerobic and anaerobic exercise in female judoka and untrained subjects

OBJECTIVES: Recent studies have indicated reduced immunity in trained athletes. AIM: To assess the effects of aerobic and anaerobic exercise on the phagocytic process in 18-26 year old trained female judoka (n = 8) and untrained controls (n = 7). METHODS: Each subject participated randomly in two different testing sessions (aerobic, 20 minutes of treadmill running at 70-80% of maximal heart rate; anaerobic, Wingate anaerobic test). Venous blood samples were drawn before, immediately after, and 24 hours after each session. RESULTS: There were no significant differences in basal values of net chemotaxis (chemotaxis--random migration), bactericidal activity, and superoxide anion release between the judoka and the untrained women. There was a significant decrease in net chemotaxis 24 hours after the aerobic exercise in both the judoka (from 64 (19) to 39 (13) cells/field, p < 0.02) and the untrained controls (from 60 (7) to 47 (12) cells/field, p < 0.05). Bactericidal activity and superoxide anion release did not change significantly after aerobic exercise in either group. There were no significant changes in net chemotaxis, bactericidal activity, and superoxide anion release after anaerobic exercise in either the judoka or untrained women. CONCLUSIONS: The decrease in net chemotaxis after aerobic, but not after anaerobic, exercise, suggests that net chemotaxis is affected by the combination of exercise intensity and duration, and not by the exercise intensity itself. Similar effects of both exercise sessions in the judoka and the untrained women suggest that training had no effect on neutrophil function response to aerobic and anaerobic exercises.     

补充精氨酸对运动大鼠腹主动脉L-精氨酸/一氧化氮途径的影响

目的:探讨有氧运动和补充外源性L-精氨酸(L-Arg)对腹主动脉L-精氨酸/一氧化氮(NO)途径及NO代谢方式的影响。方法:将36只SD大鼠分为安静+生理盐水组、安静+L-Arg组、有氧运动+生理盐水组、有氧运动+L-Arg组。有氧运动组进行8周有氧运动训练;L-Arg组在每次运动前1小时左右按照500mg/kg体重的剂量给予L-Arg水溶液1ml灌胃;生理盐水组每天以同等剂量生理盐水灌胃。采用[3H]-L-Arg同位素标记法测定腹主动脉壁L-Arg转运量、诱导型一氧化氮合酶(iNOS)活性;采用紫外分光光度计测定血清NO、抗超氧阴离子(抗)、超氧化物歧化酶(SOD)含量。结果:(1)与其它各组相比,有氧运动+生理盐水组大鼠腹主动脉L-Arg转运量和血清NO、抗含量显著下降(P<0.01),而组织iNOS活性显著上升(P<0.01);(2)两L-Arg组与其生理盐水对照组相比,L-Arg转运量和血清NO、SOD、抗含量均显著上升(P<0.01),iNOS活性稍有上升,但无统计学意义(P>0.05)。结论:(1)8周有氧运动后,腹主动脉L-Arg/NO途径中内源性L-Arg不足,iNOS活性异常上升,血清抗含量下降,NO含量减少。(2)运动前补充外源性L-Arg可明显抑制iNOS活性,提高抗含量,增加NO含量。     

Failure of target heart rate to accurately monitor intensity during aerobic dance

Fourteen untrained females (age 19 +/- 1, range 18-21) were studied to examine the heart rate-VO2 relationship during a single aerobic dance training session. These findings were used to help explain the changes in VO2max resulting from an aerobic dance training program. VO2max and body composition were determined before and after an 8 wk training period. In addition, the heart rate-VO2 responses to an aerobic dance training session were monitored and compared to the heart rate responses of treadmill jogging performed at the same VO2. The aerobic dance session elicited a significantly lower oxygen pulse than did treadmill exercise (7.2 +/- 0.3 vs 8.1 +/- 0.8 ml.beat-1; P less than 0.01). There were no significant changes in percent body fat, whereas VO2max increased by 11% (34.4 +/- 0.9 vs 38.1 +/- 0.8 ml.kg-1.min-1; P less than 0.05). No significant changes in any of the parameters tested were observed in 10 untrained controls. These findings indicate that the heart rate elicited from aerobic dance represents a lower relative exercise intensity (VO2) than that of running. Therefore, the assumption that aerobic dance training produces the same cardiovascular adaptations as running training when performed at the same target rate may be unwarranted.     

Cardiovascular changes with age and exercise

Various studies report a 0–22% per decade decline in circulatory function (VO_2max) with advancing age. Twelve exercising men (E) were followed for 28 years, mean age 43 and 71 years, initial to final measurement, while 12 dropouts (C) detrained for 21 years, with a mean age from first to last measurement of 48 and 69 years, respectively. VO₂ max in E changed from 45.9 to 39.4 ml · min⁻¹· kg⁻¹, 5% per decade, whereas C declined from 36.0 to 21.4 ml min⁻¹· kg⁻¹, 19% per decade. Resting blood pressure was unchanged in E, 119/75 mmHg, whereas C rose from 128/85 to 149/90 mmHg. The data suggest that regular aerobic exercise forestalls the usual loss of circulatory function with increasing age.     

Aerobic capacity of older adults: a training study

The effects of a four month aerobic conditioning program on heart rate, blood pressure, maximal oxygen consumption (VO2max), and physical work capacity of 55-70 year old sedentary individuals were evaluated. Twenty-eight men and women participated in either 4 months of supervised fast walking or jogging at a prescribed target heart rate or stretching exercises for one hour, three days per week. Gains in VO2max (ml/kg/min) obtained during a Balke maximal treadmill test in aerobic and exercise control subjects were 27% and 9%, respectively. At posttesting subjects in both groups demonstrated improved maximal work rate, increased treadmill time, and experienced lower resting and recovery heart rates, lower resting systolic blood pressure, and fewer premature ventricular depolarizations during exercise testing. In 67 physician-supervised maximal exercise tests, only one subject did not achieve VO2max due to exercise induced arrhythmias. No events of morbidity or mortality occurred as a result of the exercise testing and training. Subjects were contacted 4 years after study participation to determine if they were adhering to an exercise program. Sixty-four percent reported exercising at least 3 days per week in large muscle activities. We conclude that four months of supervised aerobic and nonaerobic exercise training is sufficient to improve aerobic capacity and other indicators of fitness in older, sedentary men and women, and that these previously sedentary people are likely to continue exercising on an individual basis once they have experienced improved physical capacity.     

Effets d'un entraînement en endurance sur des patients atteints de la maladie de McArdle

Objectives. – This study assesses on patients with myophosphorylase deficiency (McArdle’s disease) the effects of a moderate aerobic training program (8 weeks, 3 sessions of 45 minutes per week at 60–70% of maximal heart rate) on the physiological response during exercise.Methods. – The cardiorespiratory, electromyographic (EMG) and metabolic responses are evaluated on four patients before and after training to an acute exercise (1 h) on an ergometric bicycle (20–35 Watts) followed by 30 minutes recovery.Results. – Before training, the EMG activity is very high during the first ten minutes of exercise while oxygen uptake (VO₂) remains stable over the 60 minutes of exercise. The heart rate (FC) and the rate of perceived exertion (RPE) are markedly increased. Patients highly use circulatory glucose and free fatty acids for oxidation. During exercise, the 8-week training program reduces EMG activity, FC, RPE and the time of second-wind apparition whereas it has any effect on VO₂. At the end of exercise recovery, patients use more circulatory glucose and product lactate; moreover, their respiratory exchange ratio is increased.Conclusion. - Patients with McArdle disease show an exacerbation of cardiorespiratory, electromyographic and metabolic responses to exercise. A moderate aerobic training program induces muscle, cardiac and metabolic adaptations to physical strain and improves the tolerance of the patients to the physical exercise.