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Hemodynamic responses during prolonged sitting
Summary
Prolonged sitting causes calf blood pooling and increased peripheral resistance. Hemodynamic responses stabilize after one hour of sitting, regardless of prior posture.
Area of Science:
- Physiology
- Cardiovascular Research
Background:
- Understanding hemodynamic responses during prolonged sitting is crucial.
- Previous posture may influence circulatory adjustments to sitting.
Purpose of the Study:
- To investigate the effects of prolonged sitting and prior posture on hemodynamic responses.
- To determine the time course of circulatory adaptation to sitting.
Main Methods:
- Hemodynamic responses were measured using impedance plethysmography in young men.
- Two groups experienced different sitting durations and preceding postures (recumbency, standing, walking).
Main Results:
- Prolonged sitting increased calf venous pooling and decreased calf blood flow.
- Diastolic and mean arterial pressures increased with prolonged sitting.
- Hemodynamic responses became similar between groups after one hour of sitting.
Conclusions:
- One hour of sitting is necessary for stable hemodynamic assessment, irrespective of prior posture.
- Calf blood pooling is a primary effect of prolonged sitting, compensated by increased peripheral resistance.
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