Our goal at SleepWatch is to help you sleep better. One way we aim to achieve this is by providing you with easy access to personalized insights that we believe can help reveal something important about your sleep and overall health. With more data at your disposal, you may be able to make better choices to help you achieve your best sleep. Our newest feature introduces the ability to track your Sleeping Heart Rate Variability (HRV). This new sleep metric—which is not the same measure as heart rate—may reveal unique attributes about your sleep quality and well-being.
What is Heart Rate Variability?
Heart Rate Variability (HRV) is a measurement of the variation in time between successive heartbeats measured in milliseconds (ms). The time between successive heartbeats is also called inter-beat intervals. HRV is controlled by a part of the nervous system called the autonomic nervous system (ANS.) The ANS reacts to environmental stimulus—both positive and negative—such as having a bad day, lack of sleep, getting good news, etc. and is responsible for our “fight-or-flight” and “relaxation” responses.
Observing HRV is an easy way to potentially identify ANS imbalances that can impact your health. For nights that you wear your Apple Watch to bed, SleepWatch will provide you an Average Sleeping Heart Rate Variability result based on data measured by your Apple Watch’s heart sensor.
Why track Sleeping Heart Rate Variability?
Heart rate variability (HRV) is NOT the same as heart rate. HRV is a relatively new and growing area of health research. HRV may reveal information about your sleep and well-being that your heart rate can’t. For example, studies show that Sleeping HRV is decreased in poorer sleepers. Moreover, other studies show that Sleeping HRV decreases with age. If your Average Sleeping HRV is lower than expected for your age, this may be indicative of premature physiological aging. Unlike heart rate, which counts the number of heartbeats per minute, HRV assesses the precise changes in time between heartbeats.
Where Can I Find This New Feature?
If you use an Apple Watch Series 1 or later model to track your sleep with SleepWatch, SleepWatch will automatically track your Average Sleeping Heart Rate Variability (HRV) result if enough HRV samples were collected during your sleep. Avg. Sleeping HRV tracking is not available for the original, first model of Apple Watch. Your result will appear as a new widget on the “today”’ view of SleepWatch iOS and Apple Watch apps, as well as in your daily Apple Watch Sleep Report notifications. This widget displays your numerical result in milliseconds (ms).
Sleeping HRV tracking is available to all users. If you do not see this new feature when you open the SleepWatch app you can go to the Apple App Store and download the most recent version of SleepWatch to access this feature. Sleeping HRV is available in SleepWatch version 5.9 and higher.
Go Premium For More Powerful Insight
Studies [1, 2, 3] show that Sleeping HRV decreases with age. If your Average Sleeping HRV is lower than expected for your age, this may be indicative of premature physiological aging. A SleepWatch Premium Membership lets you see how much higher or lower your nightly Avg. Sleeping HRV result is compared to other SleepWatch users in your age group with enhanced color-coded presentation of your results.
As a Premium Member you’ll also be able to see how your 30-day average Sleeping HRV compares to others like you and to the broader SleepWatch community. These 30-day average comparisons can serve as a more stable indicator of where you stand relative to your peers.
Looking to become a Premium Member?
We hope you enjoy this new feature. Sleeping HRV is a relatively new and growing area of health research. We expect to learn more about this new metric over time and we look forward to being able to provide you additional information about it. While HRV may be a new concept for some users, we believe it has promise to help paint a better picture of one’s sleep quality and well-being.