The heart rate is one of our vital signs – it is the number of times a minute that our heart contracts or beats.1
- Heart rate varies – we have a resting heart rate, which does exactly what it says on the tin: it is the rate at which our heart beats when we are relaxed.
- Our heart rate goes up with exertion – the purpose of which is to deliver more oxygen and energy for the activity.
The heart rate shoots up dramatically in response to adrenaline, preparing us for a “fight or flight” reaction.
Adrenaline is a hormone, also known as epinephrine.2
Being frightened or surprised automatically makes the heart rate higher via adrenaline, preparing us to use more oxygen and energy in the fight or flight reaction.2
Contents of this article:
- Your heart rate
- The difference between heart rate and pulse
- Normal resting heart rate
- Target training heart rates
- Abnormal heart rhythms
- High resting heart rates
- Exercise effects on heart rate
- How does the heart keep beating?
You will also see introductions at the end of some sections to any recent developments that have been covered by MNT‘s news stories. Also look out for links to information about related conditions. You can read a version of this article in Spanish here.
- Your heart rate is the number of times per minute that the heart beats.
- Heart rate rises significantly in response to adrenaline if a person is frightened or surprised.
- Taking a person’s pulse is a direct measure of heart rate.
- A normal adult resting heart beat is between 60-100 heartbeats per minute.
- Some experienced athletes may see their resting heartrate fall below 60 beats per minute.
- Tachycardia refers to the heart beating too fast at rest – over 100 beats per minute.
- Bradycardia refers to the heart beating too slow – usually below 60 beats per minute.
- According to the American Heart Association, heart rate during exercise is around 220 minus the person’s age.
Your heart rate
Your heart is a muscular organ in the centre of your chest. Its job is to pump blood, and therefore oxygen and nutrients, around the body, and bring waste products back again.
You can check your pulse by counting how many times your heart beats in a minute. This is also known as your heart rate.
Often cited as the most important body organ, the heart is central to life and health, and without the heart’s pumping action, blood cannot move throughout your body.
A healthy heart supplies your body with just the right amount of blood at the right rate for whatever the body is doing. If disease or injury weakens the heart, the body’s organs will not receive enough blood to work normally.
When your heart pumps blood through your arteries, it creates a pulse that you can feel in the arteries close to the skin’s surface.
Heart rates increase in response to the body needing more oxygen or nutrients e.g., when exercising, or when you may need it to run for your life when being chased by a lion (the fight or flight response)!
What is the difference between heart rate and pulse?
The pulse is how many times a minute that our arteries expand and contract in response to the heart.
This pulse rate is exactly equal to the heartbeat, the rate of heart contractions, because these heart contractions cause the increases in blood pressure and the pulse in the arteries.1
Taking the pulse, therefore, is a direct measure of heart rate.1
It is quick and easy to check the pulse and MNT has a straightforward guide on finding a pulse and using it to record a heart
Normal resting heart rate
The US National Institutes of Health has published a list of normal resting heart rates. The pulse gets progressively slower through childhood toward adolescence.
The normal resting heart rate for adults, including older-aged adults and everyone over the age of 10 years, is between 60-100 heartbeats a minute.4
Athletes who have done a lot of training may see their resting heart rate fall below 60 beats a minute, possibly to as low as 40 beats a minute.
According to the National Institute of Health, the average resting heart rate:4,12
Babies have resting heart rates around 70-190 beats per minute, way higher than that of adults.
- Gets progressively slower through childhood toward adolescence
- First month of life – 70-190
- Between 1 and 11 months – 80-160
- One- and two-year-olds – 80-130
- Three- and four-year-olds – 80-120
- Five- and six-year-olds – 75-115
- Between seven and nine years – 70-110
- From 10 years of age – 60-100
- For children 10 years and older, and adults (including seniors) is 60-100 beats per minute
- For well-trained athletes is 40-60 beats per minute.
The normal heart rate undergoes healthy variation, going up in response to some conditions, including exercise, body temperature, body position (such as for a short while after standing up quickly), and emotion (such as anxiety and arousal).5
Target training heart rates
When training for fitness, we do not want to push our hearts too hard, but we do need the heart rate to increase.13
The AHA says that the maximum heart rate during exercise roughly equals 220 minus age.
|Age||Target HR zone 50-85%||Average maximum heart rate, 100%|
|20 years||100-170 beats per minute||200 beats per minute|
|30 years||95-162 beats per minute||190 beats per minute|
|35 years||93-157 beats per minute||185 beats per minute|
|40 years||90-153 beats per minute||180 beats per minute|
|45 years||88-149 beats per minute||175 beats per minute|
|50 years||85-145 beats per minute||170 beats per minute|
|55 years||83-140 beats per minute||165 beats per minute|
|60 years||80-136 beats per minute||160 beats per minute|
|65 years||78-132 beats per minute||155 beats per minute|
|70 years||75-128 beats per minute||150 beats per minute|
The American Cancer Society uses similar recommendations on target heart rates through exercise, and has a quick way of working them out based on age via an online calculator.
All of us are recommended to engage in a certain minimum level of physical activity, however. The AHA has produced a physical activity graphic representing the options, which include regular walking:13
|Exercise||Example||Minutes||Regularity days/week||Total minutes per week||Benefits|
|Moderate intensity aerobic activity||Walking, aerobics class||At least 30||5/7||At least 150||Overall cardiovascular health|
|Vigorous aerobic activity||Running, step-aerobics||At least 25||3/7||At least 75||Overall cardiovascular health|
|Moderate to high-intensity muscle strengthening activity||Weights, body pump||N/A||2/7||N/A||Overall cardiovascular health|
|Moderate to vigorous intensity aerobic activity||Ball sport, cycling||Average 40||3-4/7||N/A||Lowering blood pressure and cholesterol|
Abnormal heart rhythms
Your heart should beat steadily, with a regular gap between beats. It has an electrical system that tells it when to beat and push blood around the body. If there is a problem with this system, you may experience an abnormal heart rhythm.14
It is normal for your heart rate to vary throughout the day in response to exercise, anxiety, excitement and fear.
You should not normally be aware of your heartbeat at rest. If you feel that your heart is beating out of rhythm or too fast or too slow, then you should get it checked out by your doctor.
You might also feel that your heart has missed or “skipped” a beat, or there has been an extra beat. An extra beat is called an ectopic beat. Ectopic beats are very common and are usually harmless and do not need any treatment.
If you are concerned about palpitations or ectopic beats, you should speak to your doctor who will be able to do an ECG to assess your heart rate and the rhythm.
There are many different types of abnormal heart rhythm. What type you have depends on where in your heart the rhythm (electrical impulse) starts, and whether it causes your heart to beat too fast, or too slow. The most common abnormal rhythm is atrial fibrillation where the normal regular beating is replaced by an erratic pattern.
Fast heart rhythms such as supraventricular tachycardia (SVT), inappropriate sinus tachycardia, atrial flutter, atrial fibrillation (AF), ventricular tachycardia (VT) and ventricular fibrillation (VF) are known as tachycardias.
Slow heart rhythms such as AV heart block, bundle branch block and tachy-brady syndrome are called bradycardias.
High resting heart rates
Recent large epidemiological studies have confirmed that a higher than average resting heart rate can predict someone’s likelihood of dying. This is the case whether you have existing heart disease or not. People who take medications to lower their heart rate to a more favourable resting level have been shown to reduce their chances of dying, particularly if they also have existing heart disease.15
Despite this, it is thought that generally doctors do not use the heart rate enough when assessing cardiovascular health.
Exercise effects on heart rate
As mentioned above, the resting heart rate of athletes who are training regularly is lower than that of less active people.
The rate experienced under physical exertion also gets lower through regular exercise.
Regular athletic exercise lowers both the resting heart rate and the maximum rate during exertion.
The American Heart Association has given guidance about exercise and heart rates.
The AHA says that the maximum heart rate during exercise roughly equals 220 minus age.7
So a typical 40-year-old’s maximum heart rate during exercise is around 180 beats a minute.
The AHA also gives a target reduction that can be achieved in this exercising heart rate, through gradual increases in exertion.
It says the target zone is between 50% and 85% of the 220-minus-age figure, adding that while the rate is still getting high during exercise, the exertion can be eased off until fitness gradually improves.
These improvements in fitness apply to people who are keener about doing athletic exercise – and they can take six months, the AHA notes.
How does the heart keep beating?
Electricity keeps the heart beating. The heartbeat, and so the heart rate, is regulated by the natural pacemaker of the heart.
The heart rate and ECG reading are shown on the top line of this cardiac monitor.
The natural pacemaker is called the sinoatrial (SA) node – it is made up of special cells that create an electrical impulse, making the heart muscle contract and pump blood.8
The natural pacemaker is a part of the heart’s cardiac conduction system – the electrical system of the heart.
The electrocardiogram (ECG or EKG) gives readings of the electrical impulse as it spreads from the top to the bottom of the heart.9
It is a simple and convenient tool to check the rate and rhythm of the heart.
Perhaps the most symbolic and widely-familiar elements of medicine are the pulse, heartbeat, and the iconic shape of a normal ECG reading, which is often dramatically illustrated to the soundtrack of the heartbeat’s recognizable sound.