#141 What Should Your Resting Heart Rate Be?January 22nd, 2016 by Dr. John Day
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What Should Your Heart Rate Be?
What should your resting heart rate be? This is a question I am asked everyday as a cardiologist. Can your resting heart rate, also known as your pulse, predict just how long you will live?
A fascinating study was just published this past week on resting heart rate and lifespan. In this article, I will share the latest research on how your resting heart rate may predict how long you will live.
Michelle was a 42 year old woman who recently came to see me for a slow pulse. Her resting heart rate was 46 beats per minute (bpm) and her doctor was worried that she might need a pacemaker.
“Have you ever passed out?” I asked.
“Nope.” Michelle said.
“Do you ever get dizzy or lightheaded when your pulse is below 50?
“Nope again.” Michelle said.
In Michelle’s case, her heart rate of 46 bpm was because she was very physically active and healthy. Contrary to popular belief, if you are healthy and your resting heart rate is below 50 bpm it is generally a good thing.
Pacemakers are only indicated for people with an abnormal heart rhythm (arrhythmia) which causes their heart to beat to abnormally slow. Michelle’s heart rhythm was totally normal.
What is a normal resting heart rate?
If you consult online with the Mayo Clinic, they will tell you that a normal resting heart rate is 60 to 100 bpm. While this may be a typical resting heart rate, it is certainly not an optimal resting heart rate. Read on to find out what your goal resting heart rate should be.
How do you find out what your resting heart rate is?
To check your resting heart rate, simply find your pulse in either your wrist or neck. Then, count the number of heart beats you have in one minute. This is your heart rate in beats per minute (bpm).
Alternatively, you can also use a blood pressure machine. Blood pressure monitors will give you your heart rate in addition to your blood pressure.
Whales vs. Mice
In 1928, Dr. Raymond Pear proposed the “Rate of Living Theory.” One implication of this theory is that each mammal is given a certain number of heart beats for their life. If your “rate of living” was faster, he predicted that you would die younger.
For example, the mouse can have a resting heart rate faster than 600 bpm. However, at this fast of a resting heart rate they typically die after two years.
In contrast, the resting heart rate of a whale is about 10 beats per minute and some whales can live up to 200 years. In each case, the total number of heart beats is remarkably similar.
In humans, studies suggest that the average person gets 3 billion heart beats.
Heart Rate and Lifespan Study
This past week, media headlines loudly proclaimed, “Slow Heart Rate Doesn’t Mean Early Death Risk.” As a cardiologist knowing that a slow heart rate is actually protective, I was quite surprised to see these eye catching headlines.
Despite hundreds of studies showing that slower heart rates are associated with longer lifespans, every day I see patients who are worried that their heart rate is too slow. Let’s take a look at the scientific data from this latest study on heart rate and lifespan.
In this study, researchers enrolled 6,733 mostly middle aged people. Everyone’s resting heart rate was recorded at the beginning of the study. These study participants were then followed closely for 10 years to see who died and who was still alive 10 years later.
Here is what they found:
1. If the resting heart rate was naturally slower than 50 bpm, survival was 29% higher.
2. If the resting heart rate was artificially lowered with medications to less than 50 bpm, the risk of death was 2.4 times higher.
3. If the resting heart rate was naturally faster than 80 bpm, there was a 49% higher chance of dying during the study.
4. If the resting heart rate was faster than 80 bpm, despite medications to slow the heart, the risk of death was 3.6 times higher.
Why did people with a naturally slow heart rate live the longest?
While most people would never guess that those with the slowest resting heart rates live the longest, this study is just one of many studies showing that a slow resting heart rate is protective. Before you get too excited or worried, depending on your own resting heart rate, I need to point out that this was just an observational study.
There is no conclusive proof that a slow resting heart rate will make you live longer. In fact, a slow resting heart rate may have nothing at all to do with survival. Any survival advantage from a slow resting heart rate may be do to regular daily exercise or other factors. In other words, a slow resting heart rate may just be a sign of someone who exercises regularly.
How dangerous is an artificially slow heart rate?
The finding that people with a resting heart rate of less than 50 bpm on heart slowing medications are 2.4 times more likely to die prematurely, is a new finding. For these people, the slow heart rate may be a sign that they are on too much heart medication.
Common medications that artificially slow the resting heart rate include beta-blockers, calcium channel blockers, digoxin, and anti-arrhythmics. If your heart rate is artificially slowed to less than 50 bpm, please speak with your physician to see if you should be on less heart medications.
When is a pacemaker needed?
A pacemaker is a small electronic device placed under the skin with wires that connect to the heart. Pacemakers can speed up a slow heart.
In the study discussed in this article, a slow normal heart rhythm predicts a long life. In other words, the heart is beating totally normal but just slower than most people.
In contrast, I see patients every day with arrhythmias causing them t0 have an abnormal heart rhythm with a slow heart rate. Sometimes, their hearts may even stop beating. For people with abnormal heart rhythms (arrhythmias) causing their heart to beat too slow, a pacemaker may be indicated.
Only your cardiologist can tell you if your slow resting heart rate is from a normal rhythm or an abnormal rhythm (arrhythmia). To determine if your heart rhythm is normal or not, your cardiologist may have you wear a heart monitor.
In Michelle’s case, she had a slow normal rhythm. Thus, no pacemaker was needed and the study discussed in this article predicts she will live a long life.
Why is a fast resting heart rate so dangerous?
This study, along with many other studies, have shown that a fast resting heart rate is associated with an increased risk of premature death. There are many possible reasons why a fast resting heart rate may be dangerous. Here are some of the many possible reasons:
1. A higher resting heart rate could be from an abnormal heart rhythm (arrhythmia).
2. People who don’t routinely exercise have a high resting heart rate.
3. People under a lot of stress can have a fast resting heart rate.
4. Chronic medical problems can cause a higher heart rate.
5. Being overweight makes the heart beat faster.
What can you do to lower your resting heart rate?
If your heart beats too fast, here are some things you can do to get your heart rate under control.
1. Check with your doctor to see if you have an abnormal heart rhythm (arrhythmia) or another medical problem causing your heart to beat too fast. Getting these conditions treated can quickly bring your resting heart rate down.
2. Exercise regularly. Regular aerobic exercise (jogging, swimming, biking, etc.) significantly slows the resting heart rate over time. Most well trained athletes will have a resting heart rate below 50 bpm.
3. Practice mindfulness techniques. Mindfulness techniques like meditation, yoga, tai chi, etc. all lower the heart rate and stress levels.
4. Maintain a healthy weight.
While there is no conclusive proof that humans are only given a lifespan of 3 billion heart beats, this study certainly suggests that if you can “save your heart beats” with a slower resting heart rate you may live longer. Certainly, if you feel well and are living a healthy lifestyle, I wouldn’t worry if your normal resting pulse is 49 or 89 bpm.
What are you doing to optimize your resting heart rate? Please share your experience in the comment section below.
Also, if you have any questions about this article, please leave your questions in the comment section as well. I will try my best to answer every question.