There is significant evidence that shows that correctly prescribed exercise can have a large impact on hypertensive clients

The primary way in which this occurs is due to a decrease in peripheral resistance to blood. When exercising, the arteries leading to the working muscles in our peripheries vasodilate (get larger), allowing greater blood flow to the working tissues, resulting in increased oxygen delivery. If this process is repeated, the vasodilation effect can become more permanent. This, in turn, decreases the resistance that the blood faces, meaning that the workload of the heart is reduced.