Blood pressure is a major vital sign that is usually checked regularly to ensure an effective cardiovascular system. If there is a high blood pressure (hypertension) or low blood pressure (hypotension), medical intervention is often required.
Exercise, they say, is the best medicine and is usually recommended to people living with hypertension or at a risk of having this condition either due to genetics or other risk factors such as living a sedentary lifestyle.
Exercise has a lot of positive benefits on the body such as strong muscles, weight loss, improved flexibility but what exactly happens to our blood pressure while we exercise?
Let us first understand what blood pressure is all about.
What Is Blood Pressure?
Let us imagine pumping up a basketball or a tyre. The pump pumps air into the ball by passing air through the tube that goes into the ball.
That is how the cardiovascular system works. The heart is the main pump of the body that pumps blood through our blood vessels (arteries and veins) to the entire body.
The blood flows through the vessels in a pulsating manner causing pressure in the blood vessels as the heart pumps blood through them. This pressure is known as blood pressure.
Blood pressure is measured with a device called sphygmomanometer. The device comes with a cuff, which is wrapped usually around the left arm because of its closeness to the heart. It is usually read with two numbers and measured in mmHg.
The two numbers are usually recorded as, for example, 120/80mmHg. This is because there are two types of blood pressure; the systolic blood pressure, which is the “120” and the diastolic blood pressure which is the “80”.
Systolic blood pressure is the force between the arteries when the heart beats while the diastolic blood pressure is the force within the arteries while the heart rests.
Sometimes, the pressure in the blood vessels get too high or get to low. If they get to high, it is known as high blood pressure, which may eventually lead to health problems if not well controlled.
Being anxious may cause an increase in blood pressure but after the trigger point of anxiety disappears, the blood pressure may go back to normal levels.
Factors That Affect Blood Pressure
Some major factors have a role to play for an effective circulatory system. pump pumps factors are:
This resistance is found in the blood vessels. The heart pumps blood against this resistance through the blood vessels. As the blood vessel dilates or expands in diameter, the resistance reduces and the blood pressure reduces.
However, if the blood vessel constricts or reduces in diameter, the resistance increases and the blood pressure will increase as well.
A healthy blood vessel can expand and constrict depending on the output of blood at the time. As the heart beats, the arteries expand during the pulse wave of the systole and as the heart rests, the arteries go back to their initial state in order to maintain the flow of blood during the diastole.
This is the volume or amount of blood found in the circulatory system. An increase in blood volume leads to an increase in blood pressure.
This is the amount of blood that the heart pumps in a minute. An increase in cardiac output causes an increase in blood pressure.
What To Expect While Exercising
Now that we understand what blood pressure is all about and the factors that affect it, we will see the effects exercise has on the different factors and how they affect blood pressure.
When we exercise, muscles are working and need oxygen to work effectively.
Due to this increase in demand for oxygen and blood, the heart pumps faster to pump enough blood to the working muscles.
The heart pumps more blood than normal through the circulatory system in a minute thereby increasing the cardiac output which in turn increases the systolic blood pressure.
Since the heart is pumping more blood than the ball per minute, there will be an increase in blood volume.
Due to the increase in blood volume, the blood vessels will have to expand to allow the increased pump pumps flow to the demanded areas of the body.
This is similar to drinking water with a straw when you are extremely thirsty but the straw does not give you enough water so you remove the straw and drink straight from the bottle instead.
As the blood vessels expand in size, the peripheral resistance reduces to allow the blood to flow with ease without any resistance.
Looking at how the factors are affected, exercise causes a mild increase in blood pressure especially the systolic blood pressure because of the effort of the heart beating to meet up the demands of the working muscles.