Effect of meso-cycle prolonged exercise induced improvement in cardiovagal reactivation

心脏功能随着年龄的增长而下降。我们检验了年龄相关的心脏迷走神经复活延迟是否与年龄和运动停止后的习惯性体力活动有关，以及是否与延长中期周期运动的中枢性运动受试者的反应迅速停止有关。对22名健康儿童(8~9岁)和98名成年人(青年组，19~39岁；中年组，40~59岁；老年组，60~79岁)进行了中度踏板运动后即刻恢复心率时间常数(HR&lt；TC&gt；)和衰减率(HR&lt；DR&gt；)的序列分析。随着年龄的增长，HR_&lt；TC&>；逐渐减慢。在各年龄段内，习惯性体力活动组和久坐组HR&lt；TC&gt；差异有统计学意义(p&lt；0.05)。儿童习惯性体力活动速度明显快于青年组(p&lt；0.05)。另一方面，HR_…随着年龄的增长，More&lt；DR&gt；的速度逐渐变慢。在各年龄段内，习惯性体力活动组与久坐组的HR&lt；DR&gt；无明显差异，但久坐组HR&lt；TC&gt；下降较习惯性体力活动组慢。无论是中年组还是老年组，儿童组与中年组、老年组在习惯性体力活动和久坐不动方面的心率差异均有统计学意义(p&lt；0.05)。结果表明，随着年龄的增长，习惯性体力活动受试者的HR；TC&gt；保持良好，而少年儿童的习惯性体力活动速度明显快于青年组(p&lt；0.05)。另一方面，随着年龄的增长，HR；DR；逐渐变慢。在各年龄段内，习惯性体力活动组与久坐组的HR&lt；DR&gt；无明显差异，但久坐组HR&lt；TC&gt；下降较习惯性体力活动组慢。无论是中年组还是老年组，儿童组与中年组、老年组在习惯性体力活动和久坐不动方面的心率差异均有统计学意义(p&lt；0.05)。我们的数据表明，随着年龄的增长，习惯性体力活动组的HR；TC&gt；保存完好，而久坐组的HR_&lt；TC&gt；似乎明显延长。这些结果表明，习惯性体力活动对维持心脏中枢调节非常有用，如中枢指令和/或心迷走神经压力感受器反射敏感性，而HR；TC和GT；降低可能是神经自主控制，帮助老年人更少地预防心脏病

Cardiovagal function declines with increasing age. We tested the hypothesis whether age-related delay in cardiovagal reactivation is associated with age and habitual physicalactivity after cessation of exercise, and that is related to responses rapid cessation of central command inhabitual prolonged meso-cycle exercise subjects. Cardiovagal reactivation was examined inhealthy 22 children (8-9 yrs) and 98 adults ( young group, 19-39 yrs; middle-age group, 40-59 yrs; old group, 60-79 yrs), who were either sedentary or habitual physical activity, by using sequence analysis of time constant of recovery heart rate (HR_<TC>) and decay rate for 5 sec (HR_<DR>) immediately after cessation of moderate pedaling exercise. HR_<TC> was progressively slower with increasing age. HR_<TC> was different between habitual physical activity and sedentary group within age groups (p<0.05). HR_<TC> in children were markedly faster than young group in habitual physical activity (p<0.05). On the other hand, HR_ … More <DR> was progressively slower with increasing age. HR_<DR> was not different between habitual physical activity and sedentary group within age groups, but HR_<TC> in sedentary subjects decreased slowly than habitual physical activity subjects. HR_<DR> was different between child group and either middle-age group or old group exercise in both habitual physical activity and sedentary subjects (p<0.05). Our data demonstrate that HR_<TC> in habitual physical activity subjects is well preserved with increasing age, while HT_<TC> in children were markedly faster than young group in habitual physical activity (p<0.05). On the other hand, HR_<DR> was progressively slower with increasing age. HR_<DR> was not different between habitual physical activity and sedentary group within age groups, but HR_<TC> in sedentary subjects decreased slowly than habitual physical activity subjects. HR_<DR> was different between child group and either middle-age group or old group exercise in both habitual physical activity and sedentary subjects (p<0.05). Our data demonstrate that HR_<TC> in habitual physical activity subjects is well preserved with increasing age, while HR_<TC> in sedentary subjects appears to be prolonged closely. These results suggest that the habitual physical activity could be very useful for the maintenance of central cardiac regulation, such as central command and/or the cardiovagal baroreflex sensitivity, and that the decreased HR_<TC> could be the neuroautonomic control that helps to protect old subjects from cardiac diseases Less