The fact that regular exercise reduces blood pressure is well accepted by most people today. What is not usually well communicated is how that works. This installment is geared to help you understand the process a little better. The body is amazingly adaptable. Its reaction to exercise is no different. With regular exercise of 3-5 times per week for 30-60 minutes of moderate intensity the body will gradually adapt for improved efficiency and function. The heart, in particular, is quite adaptable. As described in the article on the heart’s response to exercise, the heart works to pump more blood with each beat which allows the heart to beat more slowly which, in turn, lowers the pressure in the blood vessels. However, this is not the only adaptation the body makes to exercise with the heart and blood vessels.
As the body uses muscles to produce movement more blood is pumped through them. Additionally, as the muscles are worked they need more oxygen from the blood to do their work. Exercise performed over a period of time stimulates the muscles to adapt to their increasing need for oxygen and blood flow. Their adaptation is to grow new, small blood vessels called capillaries to deliver the needed blood. This new growth of capillaries within the working muscles has an interesting effect on blood pressure. With more capillaries, more tubes, to hold and transport the blood, it has more room to spread out. If the blood is spread out over a greater area, the pressure throughout the whole system is decreased.
To understand this better, let’s consider the effects of water contained in a water balloon. If a balloon contains a liter of water and holds only a liter, the pressure will be quite high. If the balloon holds a liter of water, but is able to hold a liter and a half, the pressure will be lessened. This is how growing an increased number of capillaries reduces blood pressure.
Decreasing blood pressure has many microscopic effects. If the pressure within the blood vessels is high then the blood vessels themselves are at risk for becoming damaged. If the vessel is damaged, then clots and other blockages are likely to form. With reduced pressure, the likelihood of damage also decreases. Similarly, increased pressure within the blood vessels makes pushing blood through the system harder on the heart. This increased resistance to flow increases the strain on the heart and its circulation, that if interrupted can cause a heart attack.
As you can see, decreasing blood pressure is obviously a healthy goal. However, achieving it through the incorporation of regular exercise has effects that no medication can match and all without worrisome side effects.
