The predominant concern that we hear about blood pressure is hypertension, which is the clinical term for high blood pressure. Hypertension is associated with an increased risk of heart attack, stroke, and other adverse health conditions.
However, some people deal with hypotension, which is low blood pressure, either circumstantially or chronically. Although hypotension does not necessarily carry the same disease risk as hypertension, hypotension can still be concerning.
One fairly common complaint is experiencing low blood pressure after exercise. Even if you have normal blood pressure most of the time, you might find that your blood pressure drops after exercise.
So, what causes low blood pressure after working out? Is low blood pressure after exercise concerning? Is there anything to do to prevent a drop in blood pressure after working out?
In this article, we will discuss the association between low blood pressure and exercises, focusing on what causes low blood pressure after exercise, if it is problematic, and what you can do if you experience low blood pressure after exercise.
We will cover the following:
- Why Do I Have Low Blood Pressure After Exercise?
- Why is My Blood Pressure Lower After Exercise?
Let’s jump in!
Why Do I Have Low Blood Pressure After Exercise?
In order to examine the causes of lower blood pressure after exercise, let’s first look at what blood pressure is and how blood pressure is affected by exercise.
Most people have a general understanding of blood pressure as it relates to health, but when we actually try to describe what blood pressure is, it often becomes evident that our knowledge of blood pressure is rudimentary at best.
Blood pressure is essentially a measure of the amount of pressure or force that your blood exerts against the walls of the arteries as it is ejected from the heart.
The heart is a muscle with four chambers.
Blood that is ejected from the heart to be circulated around the body exits through the major artery known as the aorta after being pumped out of the left ventricle.
Based on the concepts of hemodynamics, or blood flow throughout the body, blood pressure is highest right at the very entrance of the aorta because the powerful heart contractions are most forceful and explosive right out of the muscular left ventricle when blood is first ejected into the blood vessels.
Then, blood pressure gradually and sequentially drops throughout the systemic circulatory circuit en route back to the heart.
Arteries are the blood vessels that carry blood away from the heart, and veins return blood to the heart.
Arteries have muscular walls to help propel oxygenated blood from the heart to the various extremities and other parts of your body. Deoxygenated blood returns via veins that do not have muscular walls, so the pressure in veins is quite low.
Veins rely on one-way valves to help prevent backflow of the deoxygenated blood.
When we measure blood pressure in the brachial artery around the biceps, the blood pressure measurement is actually somewhat lower than the highest blood pressure experienced in your body right at the aorta.
However, blood pressure is higher in the brachial artery than at other points in the circuit because the arm is still relatively close to the heart.
As mentioned, blood pressure is a measure of the force that your blood is exerting against the walls of the arteries.
The top number of a blood pressure reading called the systolic blood pressure, represents the highest blood pressure experienced in the blood vessels.
Therefore, systolic blood pressure occurs when the heart beats because it is forcefully ejecting blood into the blood vessels.
The bottom number of a blood pressure reading called the diastolic blood pressure, is the lowest pressure experienced during one cycle of a heartbeat.
When the heart is relaxed and the atria, the top chambers of the heart, fill back up with blood that is returned to the heart, the blood pressure is low.
Generally speaking, normal blood pressure for adults is around 120/80 mmHg.
So, what causes high blood pressure and low blood pressure in general?
The circulatory system is a closed system, so anything that causes resistance to blood flow in the arteries will increase blood pressure.
For example, constriction or narrowing of the blood vessels creates a tighter tunnel that the blood has to travel through.
Additionally, blood vessels that are stiff and not elastic or easily extensible will increase blood pressure.
Thus, when the heart forces blood through the narrow arteries, pressure along the walls of the arteries is much higher because the arteries are tight and confined.
Essentially, there is less “space“ or volume for blood to flow freely through a nice patent tube.
In contrast, when your blood vessels are dilated and flexible, elastic, or extensible, there is a wider “pipeline“ with walls that have more give to them. This reduces blood pressure because there is less resistance and more compliance to blood flow.
There are various factors that can cause either constriction and stiffening of blood vessels or dilation and increased elasticity.
Things like obesity, atherosclerotic plaques, smoking, and a poor diet can cause your blood vessels to narrow and become stiffer, which can increase the risk of hypertension.
In contrast, chronic exercise can increase the elasticity of blood vessels.
Consistent aerobic exercise also builds new capillaries, which are the smallest blood vessels. When your blood has more “tunnels“ or pathways to disperse into, the blood pressure in any given blood vessel is reduced.
Therefore, getting regular aerobic exercise is one of the best ways to combat hypertension and reduce the risk of high blood pressure.
Additionally, foods that are high in natural nitrates, such as beet greens and dark leafy greens, support the endogenous production of nitric oxide. Nitric oxide is a compound that helps dilate blood vessels and relax the muscular walls of the arteries.
This, in turn, helps decrease blood pressure.
why is my blood pressure lower after exercise?
Interestingly, although numerous studies have found that consistent exercise is one of the best ways to lower blood pressure on a chronic basis, blood pressure typically increases during an acute workout.
When you exercise, your heart contracts more forcefully and faster, both of which result in more blood being ejected from the heart and pressing against the blood vessels at any given time.
However, once your workout has stopped, your heart rate and blood pressure should decrease rather quickly, particularly as your cardiovascular fitness improves.
If you notice that your blood pressure drops after exercise, you are experiencing something called post-exercise hypotension
According to research, it is not all that uncommon to see that your blood pressure is lower after exercise, but typically you will just see a drop in the systolic number, the top number of the blood pressure reading.
Evidence suggests that post-exercise hypotension may involve a decrease in 5 to 20 mmHg for up to several hours after exercise.
But, what causes low blood pressure after working out?
It’s not entirely clear why this happens, but it is about to be a product of the phase of vasodilatory properties of exercise.
Exercise can increase the production of nitric oxide, which is a vasodilator. This means that an acute workout session can cause a drop in blood pressure while nitric oxide is produced and exerts its effect on your body.
Ultimately, this is a benefit for your cardiovascular health because lower blood pressure reduces the strain on the heart muscle, and nitric oxide increases the pliability and health of the endothelium, which is the delicate internal lining of the blood vessels.
However, if you are experiencing concerning symptoms when your blood pressure drops after exercise, such as dizziness, lightheadedness, headaches, vertigo, etc., you should speak with your healthcare provider and consider a consultation with a cardiologist.
It is also crucial to rehydrate your body with plenty of fluids and electrolytes if you sweat a lot.
One of the common causes of low blood pressure is dehydration or loss of sodium. If you are dehydrated, your plasma volume drops, so the fluid portion of your blood decreases.
If you have less volume of blood that is circulating through your body and being ejected from your heart, your blood pressure will be lower because there will be less blood volume pressing up against the walls of your blood vessels.
As long as you can properly rehydrate and replenish your electrolytes, your blood pressure should return to normal baseline values within a couple of hours after finishing your workout.
If you are interested to check out your heart rate recovery after working out, click here!