MEDICAL PHYSIOLOGY

Detailed explanation-1: -During exercise, your heart typically beats faster so that more blood gets out to your body. Your heart can also increase its stroke volume by pumping more forcefully or increasing the amount of blood that fills the left ventricle before it pumps.

Detailed explanation-2: -Stroke volume increases by about 20–50% in the transition from rest to submaximal exercise. It does not change as intensity of exercise increases from approximately 40% to 100%, despite the limited time available for ventricular filling at high heart rates during exercise.

Detailed explanation-3: -An alternative hypothesis is that the decline in SV during prolonged exercise is induced by an increase in heart rate (HR) (18). By decreasing ventricular filling time (39), increases in HR can decrease end-diastolic volume and SV (1, 30, 38).