preview image showing Heart rate jump

If you’ve been using an Apple Watch to track your resting heart rate, you might have noticed it jump up a couple of beats in late 2020. Here’s what’s possibly going on.

Warning: The writer is not a doctor. If you’re concerned about a rise in your resting heart rate, ignore everything that follows and contact your primary care physician. However, if you’re wondering why the measurements are a bit different, read on!

How the Apple Watch’s Heart Rate Measurement Changed

Your resting heart rate is generally a measure of your physical fitness (and relatedly, your overall health). The fitter you are, the lower your resting heart rate is likely to be compared with other people your age and biological sex. If you have an Apple Watch, it measures your resting heart rate when you stop moving for a bit and calculates an average throughout the day.

graph showing heart rate jump
In July, August, and September, my resting heart rate was between 47 and 51 bpm. In October, it jumped to 55 bpm and has averaged between 53 and 54 bpm since.

So, I was pretty shocked when, back in October, my Apple Watch told me my resting heart rate had jumped about six beats per minute. I hadn’t stopped working out, I wasn’t on medication, and nothing else about my lifestyle had changed.

But what had changed? My Apple Watch’s operating system.

With watchOS 7, released in September 2020, Apple officially introduced sleep tracking. Before that, I was still wearing my watch to bed—but using a third-party app to track things. This meant that my watch was measuring my resting heart rate while I was asleep.

image showing resting heart rate not tracked while asleep

Unfortunately for my ego, you’re meant to be awake when you measure your resting heart rate. With watchOS 7 and official sleep tracking, my watch was no longer taking the extra-low overnight measurements into account, so the overall daily average jumped up.

graph showing overnight heart rate

In the graph above, you can see my heart rate still dropped to 46 beats-per-minute last night.

If you also wear your watch to bed and have seen a similar stable jump in resting heart rate, there’s a good chance this is what’s going on for you, too.

RELATED: How to Set Up Sleep Tracking on Apple Watch

What Else Can Raise Your Resting Heart Rate?

Of course, software updates aren’t the only thing that can raise your resting heart rate. It’s also affected by:

  • Stress (and sometimes even the stress of software updates)
  • Caffeine
  • Your age
  • The time of day it’s measured at
  • Activity levels

There are plenty of other factors, too. If you’re at all concerned about a recent change in your resting heart rate, contact your doctor.

How to Lower Your Resting Heart Rate

A lower resting heart rate correlates with better physical fitness, which correlates with better general overall health. It’s just one of many measures of your overall wellness and not a magic number in and of itself.

With that said, you likely can lower your resting heart rate by increasing your cardio fitness, which is linked to some pretty great health outcomes, like a lower risk of heart disease, stroke, type 2 diabetes, high blood pressure, dementia, Alzheimer’s, and some cancers.

Unfortunately, the main way to do this is with exercise. If you’re new to it, a couch to 5k program is the best place to start. Over a six-week period, it takes you from sitting on your couch to being able to walk or run five kilometers (or three miles). Otherwise, talk to a personal trainer or up the intensity of your existing program.

And, of course, talk to a doctor before engaging in any strenuous activities you haven’t done before.

Profile Photo for Harry Guinness Harry Guinness
Harry Guinness is a photography expert and writer with nearly a decade of experience. His work has been published in newspapers like The New York Times and on a variety of other websites, from Lifehacker to Popular Science and Medium's OneZero.
Read Full Bio »