Hietanen E
Scand J Work Environ Health. 1984 Dec;10(6 Spec No):397-402. doi: 10.5271/sjweh.2304.
In light static exercise the heart rate and blood pressure increase much more than during dynamic exercise at the same oxygen uptake level. Heavy static exercise is characterized by a failure of the local blood flow to adjust to the oxygen demands of the exercising muscles. Respiratory and circulatory responses are dominated by an incompetence to obtain steady-state conditions, and thus the worktime is short. After the cessation of heavy static exercise a sudden compensatory increase occurs in cardiac output and oxygen uptake. Due to the higher increase in blood pressure, even light static exercise causes much higher strain on the heart than an equivalent amount of dynamic exercise. The heart responds to the increased afterload by increasing contractility and heart rate and thus improves cardiac output. In persons with a poor cardiac reserve a rise in the left ventricular end-diastolic pressure is seen, along with a fall in the stroke work index in response to the increased afterload caused by static exercise. It is possible that a discrepancy exists between work capacity during tasks demanding also isometric muscle work and a dynamic exercise test performance. The decreased cardiac reserve may first appear after the great increase in afterload, even in relatively light static work.
在轻度静态运动中，在相同摄氧量水平下，心率和血压的升高比动态运动时要多得多。重度静态运动的特点是局部血流无法适应运动肌肉的氧气需求。呼吸和循环反应的主导因素是无法达到稳态，因此工作时间较短。重度静态运动停止后，心输出量和摄氧量会突然出现代偿性增加。由于血压升高幅度更大，即使是轻度静态运动对心脏造成的压力也比等量的动态运动大得多。心脏通过增加收缩力和心率来应对后负荷增加，从而提高心输出量。心脏储备功能较差的人，左心室舒张末期压力会升高，同时由于静态运动导致后负荷增加，每搏功指数会下降。在需要等长肌肉工作的任务中的工作能力与动态运动测试表现之间可能存在差异。即使在相对轻度的静态工作中，后负荷大幅增加后，心脏储备功能下降可能首先出现。
