Cardiac output

Cardiac output is the volume of blood being pumped by the heart in a minute. It is equal to the heart rate multiplied by the stroke volume.

So if there are 70 beats per minute, and 70 mL blood with each beat of the heart, the cardiac output is 490 mL/minute.

When cardiac output increases in a healthy but untrained individual, most of the increase can be attributed to increase in heart rate. Change of posture, increased sympathetic nervous system activity, and decreased parasympathetic nervous system activity can also increase cardiac output.