The effects of static water immersion and different body postures on the cardiovascular system in healthy participants

Background: Water creates a hydrostatic pressure on the body when immersed (Bove, 2002). This redirects blood to the thoracic cavity leading to an increase in cardiac output (Q̇), stroke volume (SV) and a decrease in heart rate (HR) and blood pressure (BP) ( Šrámek et al., 2000). The aim of this study was to use echocardiography to report the full effects of water immersion.Method: Sixteen participants were immersed to the neck in waters of 30°C in three postures (standing, sitting and laying) for 20 minutes. BP, HR and a full echocardiogram of the left ventricle was performed. This was recreated on land.Results: SV (14.2%), Q̇ (12.5%), and EDV (7.7%) increased and HR (5%), SBP (11.2%), WS (12.1%) and DBP (13.9%) decreased (all P