Can a simple aerobic exercise program improve your heart health even after a lifetime of damage due to not exercising? That’s what the most recent research set to find out. The results of this most recent study blew me away.
How Blood Circulates Through the Heart
It seems a chronically sedentary lifestyle can weaken the heart as you age by causing stiffness in the left ventricle. To best explain this, let’s look at the heart and how the blood circulates through it. The heart consists of four chambers: the right and left atria and the right and left ventricles.
Our blood is continuously circulating through our body systems, back to the heart, to the lungs, back to the heart again, and, finally, back out to the body systems. Blood that returns from our body systems has used up oxygen, and it enters into the right side of the heart, is pumped into the lungs to be reoxygenated, and then circulates through the left side of the heart. The left ventricle has a big job. It is the last heart chamber the oxygenated blood visits and is responsible for pumping that blood out of the heart and back through our systemic circulation. This pumping action out of either heart ventricle (the right pumps deoxygenated blood into the lungs, while the left pumps oxygenated blood out to the body) can be measured by the ejection fraction.
What Is an Ejection Fraction?
If you link to our feature study today, you will see the mention of something called a preserved ejection fraction. First, an ejection fraction (EF) is, very simply, how much blood is pumped out of the ventricle with each heart contraction. This is measured by percentage, and a normal EF percentage for the left ventricle is about 55% or higher. An ejection fraction of about 40% would be a potential sign of heart failure. However, if you have a preserved ejection fraction, the stiffening of the left ventricle causes it not to fill with enough blood in the first place, so while your EF may measure 55%, for example, it’s 55% of a lower-than-normal amount of oxygenated blood. So if you have a chronically sedentary lifestyle, this can be associated with a preserved ejection fraction due to stiffness in the left ventricle as you reach middle age and older, increasing the risk of heart failure.
If your heart isn’t pumping out enough blood, at the borderline level, you may become easily winded with normal activity, or you may experience dizziness, fatigue, and other similar symptoms. With heart failure, these symptoms would increase, and you may also experience leg or abdominal swelling, wheezing, fluid retention, and so on.
The good news is, even if you’ve lived a consistently sedentary lifestyle for most of your life, beginning an exercise regimen in middle age, a new study suggests, may be able to repair your heart by reversing stiffness in the left ventricle and lowering your risk of heart failure. Let’s take a look at the study.
Those Over 45 and Unfit May Reverse Heart Risk with Exercise
The new study consisted of 61 sedentary but otherwise healthy subjects between 45 and 64 years of age. While 34 subjects were randomly placed in a two-year aerobic exercise group, 27 were placed in a control group (this group was assigned to nonaerobic activities, such as yoga and weightlifting). The stiffness of all subjects’ left ventricle was calculated, and in the aerobic exercise group, the stiffness decreased by 25%. In addition, the volume of oxygenated blood entering the left ventricle increased in the aerobic exercise group by 18% (see preserved ejection fraction above), providing more blood to potentially pump out to the body. No change was found in the control group on either measure.
Researchers concluded that regular aerobic exercise (at least 30 minutes four to five times per week) started in middle age, even in a population that was generally sedentary prior to that time, may significantly reduce the risk of heart failure (specifically by decreasing stiffness in the left ventricle).
However, this isn’t a golden ticket you reserve until you’re 45. It’s never too early to start an exercise regimen.
More Benefits of Exercise
With New Year’s just behind us, exercise may have been one of your resolutions. No matter how old you are, exercise can be a benefit not only as a get-out-jail-free card to repair your heart but for many other things as well. Here are a few:
- Just a quick 10-minute exercise break may recharge or sharpen your tired brain.
- Regular exercise seems to make our gut microbiome happy.
- Pushing yourself in your exercise regimen can help you lose weight and maintain weight loss.
- Regular exercise as you age also seems to make your muscles happy.
- Exercise may increase life expectancy.
The upshot? It’s amazing to me as a physician that these patients who were right on the cusp of heart failure because of a TV-watching sedentary lifestyle were able to see this amount of repair of the heart’s function. This is almost a gift that rarely comes by in medicine, for a single, simple intervention to have such a huge impact. Hence, if you’re middle aged and sedentary, please collect your repair-your-heart gift by starting a vigorous work-out program under the supervision of your physician.