What happens to end systolic volume (ESV) during vigorous exercise?

During vigorous exercise, end systolic volume (ESV) typically decreases. ESV is the volume of blood remaining in the ventricles at the end of contraction, or systole. During intense physical activity, the heart rate increases, leading to a higher stroke volume due to the increased strength and efficiency of the heart muscle. This results in a more effective expulsion of blood during each heartbeat, thereby reducing the amount of blood left in the ventricles after contraction.

As a result, the decrease in ESV contributes to an overall increase in cardiac output, which is crucial during exercise to meet the heightened oxygen and nutrient demands of the body's muscles. The decrease in ESV during vigorous exercise supports the physiological adaptations that allow for improved cardiac performance and efficiency under stress.