As most of us know, as we age, natural changes occur which can result in decreased strength. But what about changes that impact our cardiovascular system?
Are there natural changes that occur with aging that we should combat with cardio fitness exercises as well?
In this article we will explore the changes that occur to the cardiovascular system with age and what we can do to help maintain good heart health.
Anatomy of the Heart
Let’s first take a brief look at the heart muscle and the blood vessels involved in the cardiovascular system.
The heart is divided into a right side and a left side, and each side has two chambers.
The top chambers are the right and left atria, respectively, and the bottom chambers are the right and left ventricles, respectively.
Blood comes in from the rest of the body to the heart on the right side, moves from the right atria to the right ventricle and then into the lungs, where it exchanges carbon dioxide for oxygen.
The oxygenated blood then comes back into the heart and passes into the left atria and then to the left ventricle, and gets pumped out of the aorta to the body (including the heart) to oxygenate the tissues.
Keep in mind this cycle is happening on the right and left sides at the same time. Meaning, blood is coming in the right atria from the body and the left atria from the lungs simultaneously, then they pump the blood into their respective ventricle, through one-way valves. Once both ventricles are filled up, the heart pumps the blood from the right ventricle to the lungs while it pumps the blood from the left ventricle to the body and heart.
The vessels that transport the blood are called arteries and veins.
The arteries of the heart carry oxygenated blood away from the heart. The arteries branch into smaller and smaller vessels. They become arterioles and then capillaries.
The capillaries allow for oxygen and nutrients to be delivered to the tissues, which is exchanged for carbon dioxide and waste, which is carried back up to the heart (and other parts of the body) to allow for the cycle to continue.
After the blood passes through the capillaries, it enters the venules, which eventually become a network of veins that takes blood back up to the heart.1
Conductivity of the Heart
While you may know some people who have a pacemaker, we all actually have a built-in pacemaker.
It’s called the sinoatrial node, or SA node.
The SA node sends electrical impulses throughout the heart telling it when to contract.
This is what causes our heartbeat.
The first impulse the SA node sends, tells the atria to contract, pushing the blood into the ventricles.
Once the ventricles are full, the SA node sends a signal for the ventricles to contract. In doing so, the valves that allowed the blood to move from the atria into the ventricles is closed, so the blood can’t flow backwards.
Blood Pressure and Heart Rate
Blood pressure is a measure of the force of contraction and relaxation on the blood vessels. The systolic blood pressure (the top number) is the amount of force on the blood vessels when the heart ventricles contract.
The diastolic blood pressure (the bottom number) is the amount of force on the vessels during the brief period of rest (i.e. when the blood is filling the ventricles).2
This is why it’s more concerning if you have a higher diastolic number. Since it’s the number during the rest period, if it is high, it may be that there’s a condition or issue causing higher pressure than is considered “normal” or healthy.2
Heart rate is measured in beats per minute (bpm) and essentially a measure of the SA node conduction.2
To measure it on ourselves, we can place our index and middle fingers on the inside of the wrist, below the thumb.
When the SA node fires, causing the heart to contract, we feel that in our blood vessels as a beat underneath our fingers.
Natural Changes to the Cardiovascular System with Age3
With age, the blood vessels experiencing decreased elasticity and increased stiffness. This can cause increased blood pressure, as the stiff vessels are more difficult to pump blood through.
Additionally, left ventricle hypertrophy increases with age. Left ventricle hypertrophy is the thickening of the walls of the left ventricle. This causes decreased contractility of the heart and increased blood pressure, as it’s harder for the heart to pump.4
Conduction at the SA node also decreases with age.
Maximum heart rate also decreases with age. This means that we’re unable to exercise at the highest intensity we were able to when we were younger. This DOES NOT mean seniors should stop exercising. It just means that the target heart rate for cardio exercise will be lower than that of younger adults.
Also, there is a decreased responsivity of baroreceptors. Baroreceptors are responsible for monitoring the blood pressure and making changes as needed (as with a change in position).1 The decreased sensitivity with the baroreceptors can lead to feeling lightheaded with a change in position, which is called orthostatic hypotension.
How Can We Combat Those Changes?
Here’s the good news!
Exercise really works!
In a study done at the University of Texas exercising 4-5 times per week was shown to help reverse some of the negative effects of aging on the heart- even for those who were previously sedentary!5
Exercise has been shown to reduce rigidity of the vessels and decrease thickening of the heart, which helps improve oxygenation and blood pressure.5
In the study, individuals 45-64 years old completed the following each week5:
- One 1 hour of high intensity aerobic exercise (biking, walking, swimming, etc.)
- One 30 minute session consisting of a high intensity workout
- Two 30 minute sessions of moderate exercise such as swimming
- 1-2 sessions per week of strength training
And remember! The individuals in this study previously had not been exercising, so it’s not too late to start and receive the benefits!
Here’s the even better news! That’s consistent with the current recommendations for aerobic activity, so just meeting the minimum requirement is GREAT!
What’s the Recommended Amount of Cardio for Seniors?
According to the Center for Disease Control (CDC), those 65 and older should get 150 minutes of moderate intensity activity per week (the minutes in the study above add up to 150), or 75 minutes of vigorous intensity per week.
Plus, 1-2 strength training sessions per week.6
Keep in mind you can break up the time throughout the day. There’s no rule it needs to be done all at once!
Let’s say you aim to do 30 minutes a day for 5 days. You can do 3, 10-minute sessions to add up to 30 minutes!
Aerobic Workout
While this video won’t meet all 150 minutes (thank goodness, right?). But it will help you to get 10 minutes a day on the books (ALSO, feel free to watch it 3 times per day!)
Check out THIS workout with Dr. Katie Landier, PT, DPT to improve your cardio fitness!
Have the Strength to Live Life to the Fullest!
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Sources:
- https://www.physio-pedia.com/Cardiovascular_Considerations_in_the_Older_Patient
- https://www.texasheart.org/heart-health/heart-information-center/topics/the-heartbeat/
- https://www.nia.nih.gov/health/heart-health-and-aging#:~:text=The%20most%20common%20aging%20change,more%20common%20as%20we%20age.
- https://www.mayoclinic.org/diseases-conditions/left-ventricular-hypertrophy/symptoms-causes/syc-20374314#:~:text=During%20left%20ventricular%20hypertrophy%2C%20the,as%20much%20force%20as%20needed.
- https://theheartfoundation.org/2018/04/06/aerobic-exercise-can-improve-an-aging-heart/
- https://www.cdc.gov/physicalactivity/basics/older_adults/index.htm#:~:text=Adults%20aged%2065%20and%20older,of%20activities%20that%20strengthen%20muscles.
