Question

During exercise, why does systolic pressure increase, while diastolic pressure remains relatively constant?

Answer 1

To know this first we need to have an idea about what is systolic pressure and what is diastolic pressure?

Systolic pressure – Pressure due to contraction of heart

Diastolic pressure – Pressure due to relaxation of heart (pressure exerted between beats)

During exercise activity of the muscles is more. For this activity high amount of oxygen supply is needed. This oxygen supply is achieved by increasing the blood flow, which depends on the heart rate and cardiac output. Heart rate gets increased during exercise, which inturn increases the systolic pressure and cardiac output. The rise in systolic pressure depends on the intensity of exercise. For example weight lifting causes higher rise in systolic pressure when compared to normal exercises.

Apart from this, to increase the blood flow the blood vessels gets dialated (vasodialation, specifically arteries) and peripheral resistance will get reduced. Due to this the diastolic pressure maintains relatively constant or even slightly reduced. So systolic pressure increases due to increased contraction of heart and diastolic pressure maintains constant due to vasodialation.