Why does blood pressure increase with workload?

When the workload increases, the demand for oxygen and nutrients by the working muscles also increases. To meet this demand, the heart pumps more blood per minute, a condition known as increased cardiac output.

To pump more blood, the heart has to work harder. This increased workload on the heart leads to an increase in the pressure generated by the heart with each contraction, which in turn causes an increase in blood pressure.

Additionally, as the workload increases, the blood vessels in the working muscles dilate to allow more blood flow to the muscles. This dilation of blood vessels decreases the resistance to blood flow in the body, which can also contribute to the increase in blood pressure.

So, the increase in blood pressure with workload is primarily due to the increased cardiac output and decreased resistance to blood flow.