Cybulski G, Krzemiński K, Niewiadomski W, Nazar K
Department of Applied Physiology, Medical Research Centre of Polish Academy of Sciences, Warsaw.
J Physiol Pharmacol. 1999 Jun;50(2):275-86.
Several investigations demonstrated that aerobic fitness is associated with a tendency towards orthostatic hypotension whereas other reports did not show any differences in cardiovascular adjustment to orthostatic challenges between endurance trained and sedentary subjects. In the present work, the time course of changes in heart rate (HR), systolic time intervals (STI), stroke volume (SV), cardiac output (CO) and blood pressure was studied during 8 minutes following standing up from supine position in 7 healthy volunteers before and after 10 weeks of endurance training on bicycle ergometer. Impedance cardiography was used for measurement of cardiac postural responses. The training program applied in this study increased the subjects' aerobic capacity (VO2max) by approx. 18%. After training, the steady-state supine HR and contribution of the pre-ejection period and ejection time to the total R-R interval in ECG were lowered while SV was significantly increased. No significant training-induced changes were found in magnitude and time-courses of HR, STI, SV and CO changes following standing up. Diastolic blood pressure during standing was greater after than before training. It is concluded that the short-time endurance training does not affect adversely cardiovascular orthostatic response and may even improve orthostatic tolerance due to the augmentation of diastolic blood pressure response.
多项研究表明，有氧适能与体位性低血压倾向有关，而其他报告则显示，耐力训练者和久坐者在心血管对体位性挑战的调节方面没有任何差异。在本研究中，对7名健康志愿者在卧式测力计上进行10周耐力训练前后，于仰卧位起身8分钟内，研究心率（HR）、收缩期时间间期（STI）、每搏输出量（SV）、心输出量（CO）和血压的变化时间过程。采用阻抗心动图测量心脏姿势反应。本研究中应用的训练方案使受试者的有氧能力（最大摄氧量）提高了约18%。训练后，静息仰卧心率以及心电图中射血前期和射血时间对总R-R间期的贡献降低，而每搏输出量显著增加。站立后心率、收缩期时间间期、每搏输出量和心输出量变化的幅度和时间过程未发现明显的训练诱导变化。站立时的舒张压训练后高于训练前。得出的结论是，短期耐力训练不会对心血管体位反应产生不利影响，甚至可能由于舒张压反应增强而提高体位耐受性。
