Apple Watch can measure heart rate variability, providing insights into general fitness and stress levels. Heart rate variability, or HRV, measures the change in time between heartbeats. HRV is affected by factors like stress, sleep quality, exercise, caffeine/alcohol, health conditions, and age/gender.
You probably already know that your Apple Watch can measure your heart rate, but did you know that it can also measure your heart rate variability, too? Your heart rate variability can be used to give you insights into your general fitness, as well as your stress levels.
A poor heart rate variability score may also indicate that you need to make some improvements to your health and fitness, such as getting more sleep or drinking less caffeine. Here’s what you need to know about heart rate variability, and how to measure it on your Apple Watch.
What is heart rate variability?
Heart rate variability, or HRV, is a measure of the change in duration between one heartbeat and the next. If your heart were to beat at the exact same speed over and over, your HRV would be zero, but this isn’t how your heart works. The time between heartbeats is constantly changing; some gaps may be shorter, whilst others are longer. HRV measures how much your heart rate is varying over time; low HRV means the gaps between beats are fairly consistent, whereas a high score means the gaps are changing quite a lot.
What affects heart rate variability?
Your heart rate variability is affected by a number of factors. When you’re under stress, your stress hormones will increase cardiac output so that you’re prepared for fight or flight. This causes your HRV to decrease. When you’re relaxed, your heart rate slows and your HRV will increase. HRV can therefore be used to indicate when you’re under stress. Indeed, there are several third-party Apple Watch apps that aim to monitor your stress levels by measuring your HRV.
However, there are other factors that can impact your HRV, including sleep quality, exercise, caffeine or alcohol, health conditions, medications, and even your diet. Your HRV will also tend to decrease as you age and is usually a little lower in women than in men.
For this reason, there’s no specific target HRV you should be aiming for; a ‘good’ HRV score will vary from person to person. However, if your HRV is significantly outside the typical range for your age and gender, then you may need to make some lifestyle changes to improve it.
How to measure your HRV on Apple Watch
Your Apple Watch can measure your HRV, although without using a third-party app, there’s no way to see your HRV directly on your Apple Watch itself. Instead, you’ll need to access the data that gets stored in the Health app on your iPhone.
Open the Health app on your iPhone. Tap the Browse tab at the bottom of the screen. Under Health Categories select Heart. Your current Heart Rate Variability will be shown beneath your Heart Rate and Resting Heart Rate. Tap Heart Rate Variability to see more detail. You can see a chart of your HRV over a day, week, month, six months, or year.
What other devices can measure HRV?
If you don’t have an Apple Watch, there are plenty of other devices that can measure your heart rate variability. Other smartwatches, such as the Garmin Fenix 7 or Google Pixel Watch are also capable of measuring your heart rate variability. HRV can also be measured using wearable chest straps and wristbands, such as the WHOOP 4.0. You can even measure your HRV with other types of wearables, such as an Oura Ring.