Stroke Volume
Ranging from 50 mL per beat to as high as 200 mL again based on the resting state and trained capabilities. Following endurance training, stroke volume increases significantly. Some of the increase is the result of a stronger heart muscle, but it also related to an increase in total blood volume and a greater filling capacity of the ventricles during the resting phase, diastole. As more blood enters the heart, more blood can be ejected with each heartbeat, systole. The increase in stroke volume is primarily responsible for the increase in VO2max.