Heart rate

Heart rate is the number of times the heart beats each minute, measured in beats per minute or bpm. It changes based on what the body needs, like taking in oxygen and getting rid of carbon dioxide. Many things can affect heart rate, such as genetics, how active a person is, stress, diet, medicines, hormones, the environment, and health conditions.

A medical monitoring device displaying a normal human heart rate

The American Heart Association says a normal resting heart rate for most adults is between 60 and 100 bpm. Some athletes with very good fitness might have a resting heart rate as low as 37 or 38 bpm.

Sometimes a heart rate can be too fast, which is called tachycardia, happening when it’s above 100 bpm while resting. The opposite, a very slow heart rate below 60 bpm at rest, is called bradycardia. During sleep, it’s normal for heart rates to drop to around 40–50 bpm. If the heart doesn’t beat in a regular way, it’s known as an arrhythmia. Changes in heart rate can sometimes show signs of heart disease.

Physiology

Main article: Cardiac physiology

The heart beats at a certain pace, called the heart rate, to keep our body working. This rate can change depending on what our body needs, like when we exercise or rest.

Our heart rate is mainly controlled by special parts of the brain and nerves that send messages to the heart. These messages can make the heart beat faster or slower. For example, when we are scared or excited, our heart beats faster. When we are relaxed, it beats slower.

Things like feelings, body temperature, and even what we eat can affect our heart rate. Staying healthy helps keep our heart rate just right.

In different circumstances

Heart rate changes based on what your body needs to keep everything working well. When you're resting, your heart beats slower, but when you're playing or running, it beats faster to give your body more energy.

Heart rate (HR) (top trace) and tidal volume (Vt) (lung volume, second trace) plotted on the same chart, showing how heart rate increases with inspiration and decreases with expiration.

Resting heart rate

When you're sitting quietly and not moving, your heart rate is called your resting heart rate. For kids and grown-ups, a normal resting heart rate is usually between 60 to 100 beats per minute. Some athletes, who exercise a lot, might have resting heart rates as low as 40 to 60 beats per minute because their hearts are strong and efficient.

Maximum heart rate

Your maximum heart rate is the fastest your heart can beat when you're exercising very hard. It usually goes down as you get older. A common way to guess your maximum heart rate is to subtract your age from 220. For example, if you're 10 years old, you might have a maximum heart rate of about 210 beats per minute (220 - 10 = 210). But this is just an estimate — your real maximum heart rate might be a little different.

Target heart rate

When you're exercising, it's helpful to know your target heart rate. This is the range where your heart works best while playing or exercising. One way to find it is to use a percentage of your maximum heart rate. For example, if your maximum heart rate is 180 beats per minute, exercising at 65% intensity would mean your heart beats around 117 times per minute.

Newborns (0–1 months old)	Infants (1–11 months)	Children (1–2 years old)	Children (3–4 years)	Children (5–6 years)	Children (7–9 years)	Children over 10 years and adults, including seniors	Well-trained adult athletes
70–190	80–160	80–130	80–120	75–115	70–110	60–100	40–60

Formulas for estimating HR_max
Name	Data	HR_max Formula	Error
Haskell & Fox (1971)	35 data points	220 − age	SD = 12–15 bpm
Inbar, et al. (1994)	1424 men	205.8 − (0.685 × age)	SD = 6.4 bpm
Tanaka, Monahan, & Seals (2001)	315 studies, 514 individuals	208 − (0.7 × age)	SD ~10 bpm
Wohlfart, B. and Farazdaghi, G.R.	81 men, 87 women	Men: 203.7 / ( 1 + exp( 0.033 × (age − 104.3) ) ) Women: 190.2 / ( 1 + exp( 0.0453 × (age − 107.5) ) )	SD = 6.5% men, 5.5% women
Oakland University (2007)	100 men, 32 women, 908 longitudinal observations	Linear: 207 − (0.7 × age) Nonlinear: 192 − (0.007 × age²)	1 SD confidence interval: ±5–8 bpm (linear), ±2–5 bpm (nonlinear)
Gulati (2010)	5437 women	Women: 206 − (0.88 × age)	SD = 11.8 bpm
Nes, et al. (2013)	1726 men, 1594 women	211 − (0.64 × age)	SEE = 10.8 bpm
Wingate (2015)	20,691 males, 7446 females	Men: 208.609–0.716 × age Women: 209.273–0.804 × age	SD = 10.81 (male), 12.15 (female)

Clinical significance

Wrist heart rate monitor (2009)

Heart rate is how many times your heart beats in one minute. You can check your heart rate by feeling your pulse. Common places to feel your pulse include your wrist, inside your elbow, your neck, and your chest.

Doctors can also use special machines to measure heart rate more precisely. Some machines use electricity to track the heart, while others use light. Heart rate can change based on many factors, including exercise, stress, and health conditions. Very fast or very slow heart rates can sometimes signal that a person needs medical attention.