- Also called:
- pulse rate
- Key People:
- Wilhelm His
- Related Topics:
- systole
- myogenic contraction
- apex beat
- sinus rhythm
- neurogenic contraction
- On the Web:
- Harvard Health Publishing - All about your heart rate (Oct. 23, 2026)
heart rate
-
What is heart rate?
Heart rate refers to the number of times the heart's ventricles contract and relax per minute. A normal resting heart rate for adults ranges from 60 to 100 beats per minute (BPM), but it varies with age and is higher for children.
The body regulates heart rate using the sympathetic nervous system to speed it up and the parasympathetic nervous system to slow it down. Factors such as exercise, temperature, stress, and medications can cause temporary increases in heart rate, while relaxation and slowed breathing can decrease it. Consistently high (tachycardia) or low (bradycardia) heart rates may indicate underlying medical issues.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How is heart rate measured in the human body?
Heart rate can be measured in several ways. A person can use a heart rate monitor, a device that detects electrical activity, or track blood vessel expansion and contraction in the wrist or finger.
Alternatively, one can manually measure their heart rate by tracking their pulse at the neck, wrist, elbow, or foot using their fingers and a timepiece. To do so, count the number of beats in 60 seconds, or count the beats for 15 seconds and multiply by four.
The normal rhythm of the heart, or heart rate, can be altered by neural activity. The heart is innervated by sympathetic and parasympathetic nerves, which have a profound effect on the resting potential.
4 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What factors can influence a person's heart rate?
A person's heart rate, or the number of times the heart beats per minute, is influenced by various factors. The sympathetic nervous system accelerates heart rate through the release of epinephrine and norepinephrine, while the parasympathetic nervous system slows it down by releasing acetylcholine.
Several factors can temporarily increase heart rate, including exercise, high temperatures and humidity, smoking, changes in body position, certain foods and medications, stress, anxiety, and other strong emotions. Conversely, slowing breathing, relaxation, and other medications can temporarily decrease heart rate.
Consistently high (tachycardia) or low (bradycardia) heart rates may indicate underlying medical issues.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How does exercise affect your heart rate and why?
During exercise, your heart rate increases to pump more blood, and thus oxygen, to your cells. Regular aerobic exercise strengthens your heart, increasing the muscle mass of the left ventricle, the pumping chamber, allowing it to pump more blood per beat. A stronger heart is more efficient, so it can do more work with less effort.
To improve and maintain fitness, aim to exercise most days of the week. Exercising at 45 to 50 percent of your maximal capacity is adequate to improve physiological functioning and overall health.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What is the difference between resting heart rate and maximum heart rate?
Heart rate is how many times your heart beats per minute. A normal resting heart rate for adults is between 60 and 100 BPM. Children's resting heart rates are higher.
Maximum heart rate is the highest rate a person's heart can reach during exercise. It diminishes as people age. You can calculate your maximum safe heart rate by subtracting your age from 220.
Resting heart rate is lower because your cells don’t require as much oxygen when you are at rest. Adults with resting heart rates approaching 60 BPM usually have stronger hearts.
4 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Why is monitoring heart rate important for understanding heart health?
Monitoring heart rate is important for understanding heart health because it indicates how efficiently the heart is working. A normal resting heart rate for adults ranges from 60 to 100 beats per minute (BPM), but this varies with age for children.
Consistently high (tachycardia) or low (bradycardia) heart rates can signal underlying medical issues, with symptoms like dizziness, fatigue, and fainting. Regular monitoring helps assess heart strength and efficiency, as lower resting heart rates often indicate better cardiovascular fitness. Factors such as exercise, stress, and medication can affect heart rate, making monitoring essential for a comprehensive view of heart health.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
heart rate, the number of times the ventricles of the heart contract and relax (that is, beat) per minute or other unit of time. In human beings, the normal resting heart rate among adults ranges from 60 to 100 beats per minute (BPM), whereas the normal resting heart rate for children is higher and varies with age. The body moderates heart rate with the sympathetic nervous system, which releases epinephrine and norepinephrine to speed up the heart rate, and the parasympathetic nervous system, which releases acetylcholine to reduce it.
A person’s heart rate changes throughout the day as they engage in activities with varying levels of strenuousness. Exercise, exposure to higher air temperatures and humidity, smoking, changing one’s body position, ingesting certain foods and medications, along with stress, anxiety, and other strong emotions, can temporarily increase heart rate. In contrast, slowing one’s breathing rate, relaxation, and ingesting certain other medications can temporarily decrease heart rate.
A heart rate that is either consistently too high or too low may be an indication of a medical problem. A condition called tachycardia occurs in persons with a heart rate of more than 100 BPM, whereas a condition called bradycardia occurs in persons with a heart rate of less than 60 BPM. Symptoms of both conditions include dizziness, fatigue, and fainting.
" height="20" alt="HEW Logo">
Calculating heart rate
A person can measure their heart rate using a heart rate monitor (that is, a device that detects electrical activity in the chest or tracks the expansion and contraction of blood vessels in the wrist or finger). However, they can also measure their heart rate by tracking their pulse (the rhythmic dilation of an artery) at either the neck, wrist, elbow, or foot using their fingers and a timepiece. To check one’s pulse at the neck, one should lay their index and third fingers on the side of the neck, on either side of the trachea. The thumb should not be used, as a pulse can also be felt in that digit, and it may cause a miscount. Alternately, one can place their index and third fingers on the inside of the wrist, on the side closest to the thumb. A pulse can also be felt at the inside of the elbow and on the top of the foot. To calculate one’s heart rate, one should look at a watch or clock and count the number of beats that occur in 60 seconds; alternatively, one can count the number of beats that occur in 15 seconds and multiply that number by 4 (see also pulse).
Resting heart rate
Every time the heart beats, it pushes blood through the circulatory system; the blood picks up oxygen from the respiratory system and nutrients from the digestive system and carries them through the arteries to every cell in the body. While exercising or under stress, a person’s heart rate is higher and more variable than at rest. While resting, a person’s heart rate is lower, because the cells do not require as much oxygen. Adults whose resting heart rates that approach 60 BPM, such as those that occur in professional athletes and those who exercise regularly, have stronger hearts that work more efficiently. Those whose resting heart rates approach 100 BPM, in contrast, have hearts that are less efficient.
In general, a child’s resting heart rate slows as they age until, as a teenager, their heart rate approximates the rate occurring in that of an adult. According to the American Academy of Pediatrics, the normal resting heart rate (taking into account both sleeping and waking heart rates) among children ranges from 90 to 205 BPM in newborns, 90 to 180 BPM in infants, 80 to 140 BPM in children ages 1–2, 58 to 120 BPM in children ages 3–7, and 50 to 100 BPM in adolescents.
Target heart rate
Target heart rate is the range of heart rates that is healthy for a person to have while engaging in moderate-intensity exercise, which improves a person’s cardiovascular health while not putting too much of a strain on the heart. There is varying guidance on how to calculate target heart rate. Generally speaking, healthy adults can calculate their maximum safe heart rate by subtracting their age from 220; for example, the maximum heart rate for a 40-year-old is 180 BPM. The U.S. Centers for Disease Control and Prevention recommends that adults keep their heart rates within a range of 64–76 percent of their maximum heart rate for moderate-intensity exercise and 77–93 percent for vigorous-intensity exercise. In contrast, the American Heart Association recommends that adults keep their heart rates within a range of 50–70 percent of maximum for moderate-intensity exercise and 70–85 percent for vigorous-intensity exercise. Because children have higher resting heart rates, the recommended target heart rates for adults are generally too high for children.
The trusted destination for professionals, college students, and lifelong learners.
SUBSCRIBE
