How to Measure Your Heart Rate On Apple Watch 4
In this article, you’ll learn how the Apple Watch measures your heart rate and how to improve your accuracy.
Heart rate check
You can find out your heart rate at any time by running the Pulse program. Open this program and wait while the Apple Watch measures your heart rate. You can also track your heart rate while resting, walking, breathing, training, and recovering throughout the day. To simplify startup, add the Pulse extension to the watch face or the Pulse program to the Dock.
You can also enable heart rate notifications to let you know if your heart rate is getting higher or lower than your set rate, or to run a periodic check for heart rhythm disturbances.
Measuring heart rate at rest and while walking, as well as receiving appropriate notifications, are only possible for the Apple Watch Series 1 and later models. Notification of heart rhythm disturbance is only possible in watchOS 5.1.2 and in later versions. To enable heart rate alerts, they must be available in your country or region, and you must be in the country or region where you purchased the device. Find out where heart rate alerts are available.
Heart Rate with Apple Watch
If you use the Workout program, the Apple Watch continuously measures your heart rate during your workout and determines your recovery heart rate within 3 minutes after it ends. If the heart rate is not displayed, check the settings.
This information, along with other data collected, help the Apple Watch measure calories burned. In addition, the Apple Watch can measure your heart rate all day when you are not moving, and periodically while walking (Apple Watch Series 1 or later). Since the Apple Watch reads in the background only when you are not moving, the measurement intervals may be uneven. Apple Watch also calculates the daily heart rate at rest and the average heart rate when walking, comparing the background heart rate with the data of the accelerometer, if there is a sufficient number of background indicators. You can control the access of third-party programs to medical data in the Sources section of the Health program.
Certain errors are allowed, which sometimes leads to the display of excessively high or low heart rates.
Heart Rate Measurement Using Apple Watch
The Apple Watch optical heart rate monitor is based on photoplethysmography. The technology with an unpronounceable name is based on one simple fact: the red color of the blood is due to the fact that it reflects red light and absorbs green. Thanks to green LEDs paired with photosensitive photodiodes, the Apple Watch can measure the amount of blood passing through the wrist at any given time. With a heart beat, the volume of blood flow in the wrist (and with it the amount of absorbed green light) increases, and decreases between strokes. Apple Watch LEDs. flash at a frequency of several hundred times per second, so the watch can measure the number of heartbeats per minute, that is, your heart rate. An optical heart rate monitor can measure your heart rate from 30 to 210 beats per minute. In addition, it is able to compensate for a weak signal by increasing the brightness of the LEDs and the sampling frequency.
An optical heart rate monitor can also use infrared radiation. This is how the Apple Watch measures your heart rate in the background and when sending heart rate alerts. Green Apple Watch LEDs provide heart rate measurement during training and breathing sessions, as well as the calculation of the average number of steps and heart rate variability (HRV).
Apple Watch Series 4 and later also has electrodes integrated in the Digital Crown and rear panel. They can measure the electrical signals of the heart when the Pulse or ECG program is used. If you touch the Digital Crown with your finger, a closed circuit is formed between the heart and both hands, which picks up electrical impulses in the chest.
To measure your heart rate with an electric heart rate monitor, open the Heart Rate program and touch the Digital Crown with your finger. The result will be faster and more accurate, given that measurements are taken every second, and not every 5 seconds. Looking through the recorded pulse data in the Health program, you will see the ECG item. Using an electric heart rate monitor, you can also get an electrocardiogram in the ECG program.
Heart rate variability is not available in mainland China, Malaysia, Turkey, and South Africa. The ECG program is not available in all countries and regions. Find out where the ECG program is supported.
How to get the best result
Start by properly securing the watch to your hand. Even under ideal conditions, the Apple Watch may occasionally measure your heart rate inaccurately. And in rare cases, various factors make reading impossible. However, there are ways to improve the accuracy of heart rate measurements using the Apple Watch. Find out about other factors that may affect your measurements.