Cardiac output increase in exercise by

Ans: a (Increase in HR) Ref: Ganong 22nd ed/ p.632, 633In muscular exercise there is increase in sympathetic activity resulting in increased cardiac contractility and heart rate. Rise in heart rate is the major event that occur in normal individuals compared to increase in contractility, remember Cardiac output = HR X Stroke volumeTherefore, cardiac output increases in normal individuals at the cost of increase in heart rate.