Venous return (VR) = the volume of blood that returns to the right side of the heart via the vena cava.
If the volume of blood returning to the heart (VR) increases, then stroke volume and therefore cardiac output will also increase. Hence, if blood flow is to increase during exercise then venouse return must also increase.
Starling's Law of the Heart:
Stroke volume is dependent on venouse return. Therfore if VR increases SV/HR increases.
Veenous return can increase by the use of 5 mechanisms to help improbe the flow of blood back to the heart…