Many users noticed that after the latest iOS update, their Apple Watch was having several issues with the heart rate feature. From Apple Watch not reading heart rate to heart rate not recording, there have been many issues.
Is this due to a bug in the Apple Watch’s programming? Or is there an issue with the device itself? Keep reading to see what applies to your situation.
Don’t have a lot of time? Then, check out our quick tips.
- Turn on heart rate monitoring on your watch via the Settings app > Privacy & Security > Health. Tap Heart Rate and turn it on.
- Ensure you toggle on Heart Rate in your watch’s background app refresh settings.
- Turn off low power mode (watchOS 9+) or the Workout app’s power savings mode (watchOS 8 and below.)
- Turn on Wrist Detection and check the paired iPhone’s and watch’s privacy settings.
- Try wearing your watch tighter, higher up your arm, or even on the inside of your wrist instead of the outside.
Contents
Suggested reading:
- Complete Guide to Apple Watch Heart Rate Zones
- How to check Recovery heart rate on your Apple Watch and why it needs your attention
- Apple Watch guide to understanding and using Heart Rate Variability (HRV)
- Apple Watch ECG isn’t working? Here’s how to fix it
Is your heart rate not showing up on your Apple Watch face?
If your heart rate is not showing up on your Apple Watch face complication, you first need to check to see if Background App Refresh is on for Heart Rate.
Check the background refresh settings on your watch
- On your watch, open the Settings app > General > Background App Refresh.
- Make sure that you toggled Background App Refresh on.
- Scroll down the list of apps and verify that you toggle on Heart Rate.
Check your watch’s background refresh settings via your iPhone
- Open the Watch app on your iPhone.
- Select General and tap Background App Refresh.
- Verify that you turned on Background App Refresh.
- Then, scroll down the list of apps to ensure that the Heart Rate option is on.
Here you can see Background App Refresh is on for Heart Rate.
Make sure that Low Power mode is off on your watch
If Background App Refresh is on, then the next thing you need to check is to see if you turned on Low Power Mode. You’ll find this option on Apple Watches using watchOS 9 and above.
People use low-power mode to save their watch’s battery life, so the watch needs less frequent charging or, at times, stretches the watch battery.
Unfortunately, low power mode also turns off background heart rate measurements, along with blood oxygen measurements and any heart rate notifications for irregular rhythm, high heart rate, and low heart rate.
When low power mode is on, you see a yellow dot at the top center of your watch face. 
If you see that dot, let’s turn off low-power mode.
- Swipe up Control Center and tap the battery percentage icon.
- Toggle off Low Power Mode.
You can also turn off Low Power Mode in the Settings app on your Apple Watch. Go to Settings > Battery. Scroll down and toggle off Low Power Mode.
Check Power Savings mode during workouts (watchOS 8 and below)
WatchOS 8 and below do not include a low-power mode feature; however, the Workout app has a power savings mode that helps stretch the watch’s battery life when using the Workouts app.
For older watchOS versions, check if you have Power Saving Mode during workouts enabled.
When on, power saving mode turns off the built-in heart rate sensor during walking and running workouts using the Workouts app. It also turns off the Always-On display and cellular service for models that support cellular connections.
- To check this, open the Settings app on your Apple Watch.
- Then, you must scroll down to Workout, tap it, and ensure that Power Saving Mode is off.
You also find this setting in the iPhone’s Watch app, under the options for the Workouts app.
Restart or force restart your watch
If you have checked all of the above settings and they are correct, the next step you need to do is restart or, if necessary, force a reboot of your Apple Watch.
Restart your watch by powering it off, waiting a few moments, and then powering it back on.
- Press the side button on your watch.
- Tap the power button at the top, then slide to power off. For older watchOS, just slide to power the watch off.
- Once off, wait about 10 seconds before you press the side button again to power the watch back on.
If a regular restart doesn’t work or your watch won’t do it, try a forced restart.
- To force restart your Apple Watch, press and hold down both the crown and side buttons until the Apple logo appears on the screen.
- Let your watch reboot for a minute. Once it is up and running, check to see if your heart rate complication is working.
Unpair and repair your watch
If none of the above tips help, the next step we recommend is to unpair and re-pair your watch again, restoring from the backup the Watch app just created.
When you unpair your watch and restore it from a backup during re-pairing, you should not experience any data loss.
Unpairing and re-pairing delete all temporary and corrupted files and re-indexes your watch’s file system during re-pairing.
- With your Apple Watch and iPhone near each other and preferably connected to their chargers, open the Watch app and tap All Watches.
- Choose your watch and tap the “i” icon next to it.
- Select Unpair Apple Watch.
- If you have a cellular model, choose to keep your plan.
- Enter your Apple ID password to disable its iCloud Activation Lock, then tap Unpair.
- Apple automatically creates a backup of your watch and then starts the unpairing process. Once completed, start the pairing process again and choose to restore from that most recent backup.
Heart Rate not recording data during workout
If your Apple Watch is not recording your heart rate during a workout, there’s a simple fix for this.
First, check to see how your watch band fits.
Is it too loose? Too tight? For your Apple Watch to check your heart rate, the sensor must have good contact with your skin.
So make sure your watch band fits just right. If it is too loose, the sensor won’t be able to record your heart rate.
Another strategy is to wear the watch on the inside of your wrist or arm. This is especially useful if you have tattoos or have a lot of arm hair. (You could also shave your hair, but wearing it on the inside is a lot easier!) 
But if your watch fits perfectly, then go ahead and restart your Apple Watch.
After your watch restarts, go check to see if it records your heart rate during a workout.
Verify your privacy settings
If your Apple Watch still isn’t recording your heart rate during a workout, then let’s check your iPhone’s privacy settings.
- Open the Settings app on your iPhone and scroll down to Privacy & Security.
- Scroll down to Motion & Fitness and make sure that both Fitness Tracking and Health are on.
- If you use any third-party apps (for example, Strava or MyFitnessPal), make sure you also toggle those on.
Once you ensure those settings are on, open the Watch app on your iPhone.
- First, check if your watch has low power mode ion. If so, turn it off.
- For older watchOS versions that don’t support low power mode, you want to check to see if Workout Power Saving Mode is on. If it is, you need to turn it off.
- Next, you want to check if Heart Rate is on. Go to your watch’s Settings > Privacy & Security > Health and confirm. If it says off, tap it and toggle it on.
- Lastly, make sure Wrist Detection is on. Go to Passcode and make sure that it is on.
If any of those settings were incorrect, that is most likely the reason why your Apple Watch was not recording your heart rate.
But if those settings are correct and you still have issues with the heart rate feature, the problem might be with your sensor.
Is the issue with your Apple Watch’s sensor?
If you have tried all of our previous suggestions on fixing your Apple Watch’s heart rate, then the issue may be with your watch’s sensor.
The sensor is on the back of the watch itself. In the past, you may have noticed a green or red light there from time to time. That’s the sensor! 
To check whether the sensor works, you should check your heart rate in the Heart Rate app.
If everything looks normal, the issue might be due to the delay from the Workout app.
But if the Heart Rate chart is inconsistent, the issue is definitely due to the sensor.
Try cleaning the watch’s sensors
Before you do anything drastic, try cleaning your watch and its sensor.
The best way to clean your Apple Watch is to wipe it with a nonabrasive, lint-free cloth. You can lightly dampen the cloth with water, a 70 percent isopropyl alcohol wipe, or a Clorox disinfecting wipe.
All you need is a little bit of water to clean your watch. You should not use soap or other cleaning products to clean your Apple Watch. While at it, also clean your watch band!
If it’s cold outside
Something to keep in mind is that, according to Apple, cold weather can make your heart rate readings unreliable.
So, if you have issues during the colder days, that could be why. If this happens, try wearing something warmer when you do your workout.
If you still have issues after that, unpairing and re-pairing also seem to help.
Tips to improve your Apple Watch’s heart rate accuracy during exercise 
Surprisingly, a recent clinical study indicated that consumer-grade wearables like the Apple Watch were more accurate than research-grade wearables when a person is at rest. However, those same consumer wearables showed a higher error occurrence during activity, particularly when responding to changes in a person’s movement.
Update your watchOS to its latest version
Each time Apple releases a software update, it includes changes that improve your watch’s performance, including how it receives and interprets data from its sensors.
So, if you haven’t updated your watch in a while, now is a good time! 
Get excellent and consistent skin contact
Your watch’s sensors need direct skin contact to work. Verify that the watch contacts the skin and place the watch above the wrist bone. It should be snug AND comfortable–you don’t want it too loose or too tight.
If you have tattoos or large birthmarks, try keeping your watch away from these areas.
Wearing your watch on the inside of your wrist helps some people get better measurements.
Watch out in cold temperatures
Colder temperatures decrease your body’s blood flow and can impact your watch’s heart rate sensor accuracy. If you exercise in the cold, the blood flow in your wrist might be too low for your watch’s heart rate sensor to get a reading.
You get more accurate readings when exercising in mild to warm temperatures.
If you exercise in cold environments, try wearing your watch higher up your arm and not exposed directly to the cold (worn beneath your clothing, jacket, or gloves.)
Keep your wrist and arm movements steady
Moving your arm, wrist, or hand irregularly can affect how the sensor reads your heart rate. The less you move your wrist, the more accurate the sensor is.
Several studies indicated that a smartwatch’s heart rate measurement is often less accurate during cyclic wrist motions. That’s why rhythmic workouts, like running or cycling, often are more accurate in recording your heart rate than workouts with irregular movements, like tennis or boxing.
If your workout type uses a lot of arm, wrist, or hand movements, tighten your watch’s band and place it above, not on, the wrist bone.
Update your watch to a newer model
It may be time to upgrade if you use a model that came out a few years ago (or more).
With Apple’s continued research and development, newer Series watches (more recent release date) include updated sensors and technology that yield higher accuracy.
Recent studies demonstrate this, too! The study “Investigating sources of inaccuracy in wearable optical heart rate sensors” determined:
We found that devices with higher cost, a more recent release date, and a larger market had higher accuracy.
Because of the limited scope of the devices used, we cannot tease apart the effects of each of these three factors.
While device release year is noted here, all devices used in this study had software updates as of the beginning of the study.
Thus, while hardware differences may exist, software is updated frequently on these devices to help prevent obsolescence in the older technologies.
Use a chest or arm strap instead 
If you tried everything and still can’t get consistent heart rate readings, consider connecting your Apple Watch wirelessly (via Bluetooth) to an external heart rate monitoring chest or arm strap.
See this article for some of our top recommendations!
Final thoughts
I hope your watch is now tracking your heart rate!
It’s always best to run a few tests to ensure, so wear your watch for a few days and nights and look at the Health app to see if the data is there.
If everything looks good, don’t forget to turn on notifications for things like high heart rates! You can even set notifications for low heart rates or get irregular rhythm notifications (depending on local support for these features.)
If your watch continues to have problems getting your heart rate or the data it outputs don’t look right, contact Apple Support or visit a nearby Apple Store for further assistance.
And if you have a tip we didn’t cover; please let us know in the comments so we can pay it forward and share it with our readers.
It seems like on my watch the apps that track fitness interfere with each other. Heart rate works sometimes, but not consistently, I use Apple Fitness, Strava, and Peloton. I’ve had best luck with running Strava from my watch instead of from the phone, but this doesn’t always work. When I am having issues, the Strava, and Apple Fitness apps will spin and never start a workout, and won’t track heart rate. The Peloton app will show that I have started a workout, but it won’t pick up heart rate. Occasionally on the Peloton bike, I will place my watch next to the peloton logo, where it is supposed to start the Apple Fitness indoor cycle app and read heart rate, which is shown on the bike’s readout. Lately, and this has been happening more often, the heart rate won’t read or display. I have tried multiple times to close all apps and restart the watch, sometimes it works, but often it does not. Really feels like apps are competing for the heart rate and kicking each other out of the sensor.
I had the exact same issue as others with the watch not recording 15 minutes of a 30 minute run consistently. When it did record my heart rate it was super delayed. I replaced the watch several times and tried every suggestion I could find. Worked with Apple support for over a month. Nothing worked so I just accepted that is the way it is. Today my husband suggested something so dumb I had to prove him wrong… and it worked!!!
I wear my watch on my right wrist with the button on the left (where it should be). I turned the watch upside down so the button was on the right. My display was upside down for my run but it tracked my heart rate from start to end with amazing accuracy! After my run I switched the orientation so it wasn’t upside down.
Fixed… I just have a button on the wrong side.
Known fault not acknowledged but giving the equivalent of 1980’s ‘turn it off then turn it on’ or ‘go to settings’. Its a fault and my new Ultra has the same problem.
Tried all this, I think the lights burned out or got disconnected inside the watch. For a long time, the first five minutes or so of my runs didn’t record heart rate. Now I think the sensors are kaput. It’s a Series 2.
Hi Raquel,
Oh, we’re sorry to hear that your Series 2 sensors aren’t working anymore. If you haven’t already, try the following:
1. Close all open apps on your Apple Watch. To close apps, press the side button once, then swipe on each app from right to left and tap the large red X to close it.
2. Once you close all apps, force restart your watch by pressing both the side button and Digital Crown button at the same time. Keeping pressing both buttons until you see the Apple Logo on your watch’s screen.
3. After restarting, open the Watch app on your iPhone and unpair your watch–unpairing automatically creates a backup of your watch’s content.
4. After unpairing, re-pair your watch and set it up as new (don’t restore from the backup just yet.)
5. Once set up as new, check these settings:
On your iPhone, in the Watch app, go to: My Watch > Privacy > turn on Heart Rate and Fitness Tracking.
Also check My Watch > Workout > turn off Low Power Mode (might also be called Power Savings Mode)
Staying in the watch app, go to My Watch > Passcode and turn on Wrist Detection
Then go to your iPhone’s Settings app > Privacy & Security > Motion & Fitness and verify that both Fitness Tracking and the Health app are enabled.
6. Finally, restart both your watch and phone and run some tests to see if your watch’s HR works.
If it does work, you can either keep the watch as is or unpair it again and restore from that recent backup from the first unpairing.
My watch stopped recording my heart rate. Did all the check out but still not working. It will work if I put finger on crown. I have a series 6 watch.
the same as you and i just update to os9.1
Me too, heart rate and activity suddenly stopped working on my apple watch series 5, 2 weeks ago. I Tried all workarounds on the internet. Even the update to watchOS 9.2 didn’t help. Heart rate works only if I put my finger on crown.
My Apple Watch is not recording my heart rate from 6pm to 6am: and/ therefore my sleep app doesn’t record my sleep?
What is suddenly causing this??
Hi Stephanie,
Sorry to hear that. I assume that your watch is tracking your heart rate during the daytime, up till 6 p.m. With that assumption, have you set a sleep schedule on your Apple Watch and turned on sleep tracking? Open your watch’s Settings app, select the Sleep app, and then scroll down and turn on Sleep Tracking. Once on, open the Sleep app on your watch and set up a sleep schedule.
If you prefer, you can adjust these settings in your iPhone’s Watch app > Sleep app and toggle on Track Sleep with Apple Watch. Then, open your iPhone’s Health app, choose Sleep from the Browse tab, and adjust your schedule and other sleep features there.
We also suggest wearing your Apple Watch higher on the arm, above the wrist bone, when sleeping to get more consistent data.
Hope that helps! Frankly, the way Apple designed sleep tracking is messy since there are different data options in the Watch, Watch app, and the Health app.
We have a few articles that may be helpful for tracking sleep:
How to turn on Sleep Mode on your Apple Watch using watchOS8
Apple Watch screen not dimming during sleep? It’s an easy fix
How to track your sleep using Apple Watch or iPhone using third-party apps
Which fitness app are you using? I have been experiencing exactly the same behavior. I use Map My Run. It seems like starting the Heart Rate app on my watch during a Map My Run workout can “wake up” heart rate refreshing. I will experiment with the Apple Workout app and see if the behavior is app-dependent.
For the past 10 months, my apple watch is very inconsistent in recording my heart rate during 5-mile runs.
When I got the watch it would not read the first 15 minutes of my 45-minute run.
The Apple store was not much help. After my second trip to the apple store, they gave me a new watch.
I have covered most if not all the tips provided in the blog. Placing the watch tight high up on the wrist seems to be the most important tip.
Over the last 10 months, the watch would stop tracking my heart rate for 5-15 minutes at various points during the run for 75% of my runs.
Once in a while, it would track the whole run. At various points in many of the runs, the watch would show a spike in my heart rate from 130 to 160 BPM.
I did a stress test yesterday. The watch did not perform well during the stress test.
It tracked well in the beginning of the test at 80-90 bpm. Then stop tracking the heart rate. When I got up to 121 bpm the watch stared tracking again jumped to 145 bpm, then 152 bpm, and then stop tracking during the rest of the stress test which lasted 11 minutes.
The highest heart rate recorded by the 12 lead chest monitor was 128 bpm.
The stress test confirmed that the Apple watch is not always accurate and at times very inaccurate.
Even more frustrating is how it stops recording the heart rate for 10-minute stretches during a 45-minute run.
I have had issues with rapid heart rate and was concerned that the periods the watch stopped recording the heart rate were actually rapid heat beats.
The stress test showed that the apple watch is very unreliable. At times it gives the impression that it is tracking the heart rate accurately but it is not to be trusted. The watch is frustrating and often inaccurate.
It’s the watch, Tom. I’ve had almost exactly the same problems (arbitrary measurements for the first few minutes, flatlining during a run, etc.) with both a Series 6 AND Series 7.
I’ve tried everything. Apple support was of no use whatsoever. They just kept elevating the issue with no resolution, and insultingly, at every stage, they suggested the same fixes, none of which worked.
Finally (after 8 months and multiple visits!), I happened on an assistant at the Apple Store who was a runner. He looked at my Strava records, saw the watch had not been working properly, and immediately exchanged it without question.
The new watch (series 7) is a little better, but still has problems (eg not recording for the first few minutes). What I have found is that using the shorter strap allows me to make it much tighter on my wrist (it leaves quite a dent!). Also, I have Reynaud’s, and if I don’t wear gloves on colder days the watch frequently flatlines.