Popis: |
The paper gives and compares data on the orthostatic tolerance of man exposed to different hypokinetic conditions of varying duration -- water immersion (10 days), supine position in the chair close to the mean physiological rest posture (7-20 days), bed rest (10-120 days) and altitude chambers (3-70 days). The tolerance to orthostatic tests decreased to a larger extent after experiments in which the motor activity was significantly lowered: water immersion, supine position in the chair and 120-day bed rest; orthostatic tolerance reduced to a lesser extent after altitude chamber experiments. The level of decline of the motor activity was more important than the time of hypokinetic exposure. The most noticeable reduction of adaptive capabilities of the cardiovascular system developed during the first 30 days of bed rest. |