How to fix Apple Watch heart rate monitor not working

fix Apple Watch heart rate monitor
Figure 1 — no measurements at start and middle!

Fix Apple Watch heart rate monitor!

About six months ago I noticed that my Apple Watch wasn’t consistently reading my heart rate during running workouts. The watch started displaying “measuring” my heart beat for minutes (see Figure 1), especially at the beginning of a run. Sometimes the heart rate monitor stopped working to such an extent that I couldn’t even get a few readings during a 25-minute run (see Figure 2). I love my Apple Watch but it was time to fix my Apple Watch heart rate monitor.

Figure 2 – no heart rate chart!

After doing some research, here’s what I’ve curated from various internet sources, summarized in one convenient place.

The first thing to determine is whether your watch’s heart rate monitor is working at all!

If your Watch completely stops reading heart rate during workouts

Check the following settings on your watch.

—On your iPhone, go to Settings > Privacy > Motion & Fitness and check that both Fitness Tracking and Health are On.

—Open your iPhone’s Watch app and:

  • Go to General and make sure that Workout Power Saving Mode is Off.
  • Next, go to Privacy and check that both Heart Rate and Fitness Tracking are both On.
  • Finally, go to Passcode and check that Wrist Detection is On.

If any of these settings are incorrect, they will prevent your watch from reading your heart rate during a workout. Set them correctly, and test your watch again.

If your Watch is flaky reading heart rate during workouts

—Clean the sensors on the back. The two that read your heart rate during exercise are the white LEDs at 3 and 9 o’clock that you may have noticed flashing green from time to time.

—Make sure that the watch is snug on your wrist.

—Apple says that cold weather conditions can make reading your heart rate less reliable. If the flakiness of your heart rate monitor seems to be worse on cold days, try wearing warmer clothing on the arm where it’s fastened.

—If your heart rate monitor is still flaky, try the approved Apple resetting options listed here.

One workaround to try

[Updated on April 16, 2020] While running today I thought of a workaround that I believe is worth trying.

When you’re not running the Activity app, an Apple Watch only reads your heartbeat every ten minutes. One possibility is that — due to unknown circumstances —  during the first few minutes of your exercise, your heart rate is changing too fast for the watch to accurately measure it. Since the watch’s Heart Rate app turns on the constant heart rate monitor, try the following:

Before you start your exercise routine, select the Heart Rate app and wait until it shows you your heart rate before starting the Activity app and your exercise.

Since my watch is now OK I can’t test this, but perhaps it will work for you. Please share your experience in the comments.

What to do when none of the above helps

I tried all of the suggestions above. However, I was skeptical that any of them would work, because I’d seen a slow degeneration in the reliability of my watch to read my heartbeat while using my watch for the same workout over the same route for months.

I concluded that my watch heart rate sensor was defective. Luckily my Apple Watch Series 3 was still covered by AppleCare. I took it in to our local Apple Premium Service Provider. As I expected, defective Apple Watches are returned to Apple for repair or replacement. Before sending it back, I unpaired the Watch from my iPhone (important!), which backs up the Watch contents to the phone.

After a week turnaround, Apple sent back a new replacement watch. It was a little strange not wearing a watch for a week, and it was interesting to see the limited workout data provided by my iPhone compared to what I was used to from my watch.

I’m happy to report that the replacement watch now works perfectly during my workout. Figure 3 shows the continuous heart rate chart shown by the new watch. And Figure 4 compares typical charts from the old and new watch.

Figure 3 – the replacement watch
fix Apple Watch heart rate monitor
Figure 4 – comparing typical old and new Apple Watch heart rate charts

Conclusion

Many people have reported that the heart rate sensors on an Apple Watch have become unreliable. Unfortunately it seems that the watch heart rate sensors can degrade over time, and the various “fixes” suggested online might not always be successful. I was lucky that AppleCare still covered my watch. I don’t know what Apple would charge for an out-of-warranty fix or replacement. If you don’t have warranty coverage, I suggest politely pointing out that this defect seems to be widespread, and asking whether Apple will replace your watch anyway. Good luck!

Please feel free to share any other fixes, suggestions, or experiences with this problem you’d like to add in the comments below!

60 thoughts on “How to fix Apple Watch heart rate monitor not working

  1. Thanks for sharing your experience. My watch is getting close to a year old and the heart rate tracking seems to be degrading too. I’ll go in before my apple care expires and get it replaced.

    1. My heart rate is 50 at rest so when I go walking my pulse doesn’t really get high so my watch doesn’t always detect that I’ve done a walk or any exercise is there anything I can do??

      1. Hi Amanda,
        This is a commonly reported issue. According to Apple, “the Activity app aims to identify activity that equals or exceeds the intensity of a brisk walk. This requirement applies both during general daily wear and when recording workouts via the Workout app”.

        So you may not be walking “briskly” enough for the watch to count your walk as exercise.

        It’s also possible that you need to edit your personal health information.

        For more information on both these issues, check https://discussions.apple.com/thread/8226802.

  2. Please see the new section I’ve just added “One workaround to try” (April 16, 2020) for a procedure that may help. If you get the chance to try it out, please share your experience!

  3. I’m a Biomed (I repair medical equipment) and I would be very surprised to learn the sensors degrade over time. The Apple Watch uses light sensors and an algorithm to measure your HR, in 20 years, I have never seen any of these types of sensors with a limited lifespan. Typical causes of failure are physical damage to the sensor or wiring. Either Apple has an unusual issue with their hardware degrading over time or something else is causing this issue.

    Thanks for posting this though, my fiance is having the same issue and I was looking for some btdt from people. Going to try some of the other things you suggested.

    1. Yes, the issue surprised me too, and I wish I had a definite answer. But the replacement Apple Watch fixed the problem (at least until now) for me, which is evidence that some kind of hardware problem may be involved.

  4. I had this same problem. My heart rate was routinely displayed on my watch in all situations except while running. I finally determined that my link type band was too loose when running. Apparently it did not make consistent enough contact with my wrist as it flopped around a bit while running. I did not want to take another link out because then it would be too tight. I wedged a piece of foam under latching part of the watch band which snugged up the back of the watch to my wrist. This solved the problem. I only use that while running.

  5. Thanks for posting. Wish I came across this sooner. And also should have taken my watch to Apple before my Apple care expired. My watch does this and also pulls random readings that can’t be correct: goes from 88 to 160 to 53 to 88 within minutes. There’s no way I’d be functioning normally with that kind of HR variation.

  6. Why would my heart rate reflect in yoga but not in outdoor walk / run ? It’s very frustrating – Watch is not even six weeks old – I’ve done all the upgrades de link re link as directed by the Apple store but it still does not work

    1. That’s the same thing that is happening to me… I’ve unpaired my watch, recalibrated it.. records fine on yoga, cycling and weight lifting… it gives me the “chart unavailable “… I bought my SEwatch on the 11th of February 2021… upgrading from 3…. I’m so frustrated..

      1. My watch only stops measuring when my phone (paired) is in an area with no cell or WiFi connection. That why outdoor walking or running g is where it mostly happens.

        1. Samantha, I wish that your answer explained this problem for me, but at home I run the same (rural) route every day, and the times that my Series 3 stops measuring my heartbeat are inconsistent from one day to the next. Pre-pandemic, when I traveled, I’d see the same erratic measurements when I was running routes in a city with strong cell signal.

  7. A superbly documented summary ! My series 4 running workout record looks just like your OLD watch image. The workout chart is much better during stationary bike workouts, in which I note there is little arm movement.

  8. Hi,

    this is important!
    I thought my watch heart rate monitor was not working well, but then I decided to use a nylon band which you can adjust precisely on your hand.
    in addition make sure the watch is about one inch from your wrist.
    now it’s working fine fo me!

  9. So this issue ONLY occurs while running for me. If I do crossfit (which supposedly is a hard exercise to capture HR on) or cycling, the watch is flawless and never loses monitoring! Running, it SUCKS! It can barely keep a measurement even when I start the HR App first. It has something to do with the swinging of the arms, that throws it off and yes, the watch is snug and does not move around. Its very frustrating.

    1. Mike, I agree it probably has something to do with arm movement, since I, like you, never see the issue during other exercise routines where my arms don’t move as much. I am still seeing the problem while running, even with my new watch, but it’s so inconsistent from day to day. I suspect, as other commenters has mentioned, it’s related to the precise positioning of the watch on the wrist and the tightness of the strap. But, despite fiddling around, I haven’t found a way to reliably avoid the issue.

    2. So I have the latest Apple Watch series 6 barely few months old and experiencing the exact same problems. Sometimes no HR reading at the beginning of the run. Sometimes crazy spikes. Mid run, the HR detection will stop with large gaps. If it comes back it will have inflated HR readings that I are impossible for me. I also do CrossFit and do not experience these issues. One way I have found to force the watch to get back on track is to open the HR app and force it to detect a reading. Usually need to stay still for it to work, which also means disrupting one’s run. I do have a case open with apple and provided some diagnostics for research.

      1. Amar, thanks for sharing your experience. It’s interesting to hear that your Series 6 is having the same problem, as I have been wondering if this was a defect with the Series 3 I own. Currently, I think this is a hardware defect on these watches because of my experience, documented on this page, where my replacement watch was free from the problem for many months but eventually started displaying the same symptoms again.

        Please let us know here if you get any useful response from Apple.

      2. I’m having exactly the same problem starting a month ago with a Series 2 that has been perfectly reliable for the past 4 years. I think there must be a recent software change that’s at least partially responsible for the problem, as it seems to affect both older and newer models.

        1. ZM, appreciate you adding your experience. I don’t think it’s a software update issue myself, given that when my troubled Series 3 was replaced with a new watch from Apple, the problem disappeared for quite a while before reappearing. Maybe there are multiple reasons why the device can fail to reliably display heart rate while running?

          1. I’m having the exact same issue on my series 6. It always records the first minute or 2 of my run then skips around 6 minutes then continues to record the rest of the run. The result is that my HR looks like it jumps from 60 to 160 after the first KM. I’ve just had a replacement sent and the exact same thing is happening so I’m leaning towards something software related.

    3. This is very interesting, and also correlates with arm movement for me. I have had a series 5 for a little over a year. I first saw the problem while walking on a treadmill and now see it a lot while doing apple fitness + rowing workouts. Scrolling back through my workouts, I do not see the problem with cycling, yoga, core, etc workouts.

      I have tried reversing the watch so the sensors are on the inside of my wrist, cleaned the sensors, and sometimes have the watch band so tight it’s painful. I have contacted apple support. I hope this can be resolved, it’s frustrating.

  10. Thanks for all the comments about not reading heart rates during work outs. I have all the setting turned on described above in the this chat. I am on my 2nd series 5 watch in 4 weeks. Sometimes I do get a reading. I run with both a fit bit charge and the apple watch. The fit bit always gives me a reading. The fitbit routinely shows 160 BPM during my runs. A year ago I ran with a 12 lead holder heat monitor and it agreed with the fit bit. Today I ran 1 mile 9 minutes and the watch stop reading 30 second in the run at 79 BPM. The times I did get it to read was a slow increase in my pace. slowing down when it stoped recording then speeding up. Finally got it to read 140 bpm for 30 minutes. I am doing a 10 mile run tomorrow and hope a tighter wrist band will help. However it sounds like fast changes in heart rate cause the watch to stop recording. All the apple store say is that is strange and gave me a new watch. It is nice to know that many people are having the problem.

    1. Tom, you mention another possibility: that the Apple Watch simply doesn’t handle rapid changes in heartbeat well. That may be what’s happening to me too. Hearing that other heartbeat monitors don’t have this problem implies that Apple’s tech is, perhaps, inferior.

  11. Adrian,
    I Got the watch to track heart rate for this morning’s 10 mile run by tightening the wrist band one notch and positioned a little closer to my elbow but still on my wrist. Heart rate was mostly 140 bpm with one spike to 177 bpm. It drifted up to 160 bpm at the end of the run. The Fitbit was 140 bpm for first 2 miles then jumped up to 165 bpm for the rest of the run.

    The GPS pace from the apple watch seemed to vary faster and slower than my actual pace on hills. 8-12 minutes per mile for apple watch and 8 min 30 sec to 9min and 40 sec for the Fitbit.

    I could not cut and past any of the graphs from iPhone or Fitbit app into this comment. How do you do that?
    regards. Tom

    1. Hi Tom,

      Thanks for your detailed comparisons of your Fitbit and Apple Watch. It sounds like the Watch updates heartbeat more often that the Fitbit and also shows more pace variation. That could be a good thing in both cases, as long as, of course, the reports are accurate. Do you think your actual pace changes are tracked better by the Watch than the Fitbit?

      Until recently, I used Disqus for comments here. But a recent upgrade made the plugin seriously increase site load time, so I’ve gone back to the standard WordPress comment system which doesn’t support inline graphics. If your graphs are hosted somewhere, you could supply a link to them in a comment.

  12. Nice write up. I have another issue as this didn’t fix my watch issue. My watch seems to have Bluetooth issues. It keeps connecting and disconnecting to my phone as I work out. When it is connected it reads heart rate. It says move closer to your iPhone but I’m 5 feet away.

  13. Brilliant help thank you. I’ve switched off Workout power saving mode in the hope that my Apple Watch will record my heart rate whilst running. It is fine when I play tennis. It seems the Nike Run Club app stops it from working somehow. Shame because I’ve accepted a challenge from my family so I need to use NRC to record my distances.

  14. Thanks to Adrian and all who have commented on the apple watch heart monitor while running.

    Since my Sept 30, 2020 comment to this blog the performance of the watch is inconsistent. Of 20 runs since then only 2 have provided heart rate for the entire run. A very tight fit on the wrist is required. 90% of the time it does not record the heart rate for the first 10 minutes of a 50 minute run. It does a pretty good job of recording the heart rate for the next 40 minutes but even that is not consistent. the positive is that it It usually gives me the expected heart rate of 130 bpm for a 68 year compared to the fitbit which records 160′ bpm The inconsistency does make me wonder if the heart rate is accurate.

    I am disappointed in Apple’s failure to recognize and address the issue. It seems to be happening to a few people but apparently not enough. Are most runners resorting to a sports watch or a chest strap monitor? Unfortunately I could not figure out how to paste snap shots of the heart rate in the the comment section and I don’t have an online host for them either. Does only one comment since October mean other people are not experiencing the problem or just willing to living with it?

    1. Tom, thank you for providing your update. As I reported in the post, my replacement Series 3 from Apple that I received in October 2019 did not initially have the problems you and I and many others have experienced. Sadly, its ability to measure my heart rate throughout a run has deteriorated again, back to the same intermittent readings I’ve documented.

      To me this implies there’s a hardware degradation of some kind over time on these watches. Why it only seems to affect heart rate readings during running is a mystery. Like others have reported, I don’t see it during other activities, such as Mixed Cardio. As my Watch is now out of warranty, I’m just going to have to live with it.

      Frustrating!

  15. I stumbled upon this on the web, since I have had a heck of a time with getting my Apple Watch to consistently read my heartrate during my runs and walks. This has been frustrating, since the sole purpose of this watch for me is for fitness.

    First, I should note that I was experiencing problems with my Apple Watch Series 3 over the course of the last few months (?). (I hadn’t been paying close attention to heartrate, since I had to quit running for a year due to a hamstring injury). But I think things seemed to get worse after the software update to watchOS 7 a few months ago.

    Recently I got a Series 6 watch, assuming that it would resolve the issue. Unfortunately, nothing changed, as reported by another person here. I have tried EVERYTHING and have an ongoing open case with Apple.

    Here is what I’m wondering after a gotcha moment today. Is the Sport Band a big problem for me? It seems like the holes are not sized appropriately for me, since it is either too tight or too loose.

    Today I did some testing. I tested my blood oxygen and noticed that I was getting weird numbers or an error. I have a new Nike Sport loop band, so I switched it out. Guess what? I received an instant accurate reading.

    I went for a run, and I noticed this… I couldn’t get a consistent or accurate heartrate recorded with the Nike Run Club app. I switched to the Apple Fitness app and started recording my run there. The heart rate was too low and not updating. I paused the workout and opened the heartrate app and then resumed my run. The rest of my run had a consistent and accurate read.

    This is an expensive watch! I have noticed some other funkiness with the V02, so I’m wondering if some software updates have been a source of problems. I also think that it has been colder, and I tend to have cold hands, so maybe this will be an ongoing issue for me.

  16. I am having the same issue with a brand new series 6, heart rate recording is fine until I start exercising, it then stops recording until I stop exercising. Feels to me like its a deliberate ‘by design’ software issue. Apple help desk have been no help at all with this….

  17. Hi All

    I have the same issue on my Series 6 watch purchased in Oct 2020. It seems pretty much like I have had problems with heart rate readings all the way through. Typically I get a gap at the start and once the reading starts it records consistently.
    My Son – less than half my age has the same issue with the watch. I use a Nike sport band and he uses a braided loop

    I have lost count of the number of tickets with Apple and I have provided diagnostics. After 3 months of raising tickets I was told that that was ‘expected functionality’ and maybe I should try connecting a chest HRM to the watch!!

    What is frustrating is that there is no one in Apple you can talk to to get a refund so I can start living my life with a chest strap

    Expensive and ineffective paperweight

    1. Well, that’s interesting! Inconvenient, but interesting. I will try this myself. Does anyone else want to see if this makes a difference?

      1. I also have switched to wearing on front of wrist last month. After months of bad readings it is finally working worn there. As you said “inconvenient” but if it works I will take it as a win.

    2. I am glad that works for you, though it’s somewhat inconvenient to switch it before running. However, I have now tried wearing my watch this way on several runs, and it has not solved the problem for me.

  18. Hello Adrian! Thank you for writing this article. I am having the same problems as you. Lately workouts have become an absolute pain in the back because I’m not getting heart rate for the first ~15 minutes. It can be more, it can be less. Putting the watch on another arm doesn’t seem to make it better, so this is probably not to do with the skin being compressed for long periods of time (I wear my watch 22 hours a day). One thing that seems to work for me is restarting the watch, but it doesn’t seem to start measuring correctly straight away, which is strange. Tomorrow I will try to restart my watch BEFORE I do a workout and see if that affects things. Interestingly enough, once the watch manages to measure my heart rate when it’s above ~130 bpm, it starts to get consistent measurements, even if I then reposition the watch.

    So it probably doesn’t have anything to do with skin perfusion/positioning of the watch, but some kind of hardware/software issue.

    Another thing to note is my problems seemed to have started in October, which coincides with the release of watchOS 7. I still have 2 months of warranty left, so maybe I can get my watch replaced? I will report back here if I find any solutions for this problem, as so many seem to be having it.

    1. Alexey, thank you for some interesting information. The restarting observation is a new idea to me, and I’ll be interested to see if it makes a difference.

      I also have the same experience as you: once the heart rate registers, the watch is usually able to keep measuring it for the remainder of a run. Though not always, in my case.

      As I wrote in the post, I requested a replacement for my watch while it was still under warranty. The new watch worked perfectly for a while, but eventually started showing the same symptoms again. I’d ask Apple for a replacement. If they’re not going to investigate and fix the problem, you might as well get a temporary improvement (if your experience is like mine).

      Yes, please let us know what you find out with your experiments—and good luck!

      1. Hello! Thanks for your good article, I faced with the same issue with my 5! I vot it last september, but from February I check the HR during my running. I tried everything: tight and loose the band, clean the senzor during the running. Sometimes at the beginning, sometimes during it losts the HR. I tried my boyfriend watch (same as mine), till 26 minutes, everything was OK, but after it losts HR, minutes later it showed a higher one, after it losts again and so on. During his bicycle, the measuring is OK. We tried to reconnect and recalibration as well, and I checked everything what you wrote. But Hungarian Apple service said: this issue is brand new for them, they have to test it. What can be the result? I would not like to wear a chest strap, so it is a very expensive game for running 🙁
        I would like to try what happens if I turn the watch to my lower wrist?

  19. I just replaced my series 6 for this reason (they replaced it, was under Apple Care) and guess what?

    It still is spotty. I’m unsure what it going on. I’m basically in the same boat with all of you. I used to swim a lot with it (before pandemics closed the damn pools!) and it rarely ever had an issue with heart rates. I only say this because my watch seems fine for the first few minutes, then basically doesn’t measure most of my runs. I run for 1.5 hours usually–so that’s a lot of missed data.

    Anyway, I like a lot about the watch, but in the end my conclusion is that it’s really just not very good at a heart rate monitor. Best of luck, and thanks for this article.

  20. I had the same problem. I’ve unpaired and paired back the watch and right now the problem looks fixed. I will try in the next days with a real workout session.
    Thank you

  21. I’m having the same issue. Lately, when I’m running at my slower pace, my heart rate should be in the 140/150 range. I’m getting spikes at 168, 172, and even 183. This usually happens when my watch is “looking” for my heart rate and then comes back. Then, it drops back down to 150s or so. I’m freaking out that there’s a cardiology issue happening. It sounds like it’s likely the watch, but better safe than sorry!

  22. I’m having this problem too, and have tried some of the fixes here none of which have worked. I’d say the obvious verdict is that as a running watch, the Apple is pretty terrible.

  23. I had to Download the Beta Version to get mine to work not sure why but its working now I noticed it

  24. After reading this blog I switched my Series 4 watch from the left wrist to the right wrist for workouts only. This worked 3 times flawlessly so far (2 runs and 1 hike).

    I am right handed and it appears the wrist circumference is larger then the left (probably a normal occurrence). I tried all kinds of things for a few years before this with no great success. My band is a Velcro like one from Apple. I don’t think tightness is the answer. It may be that the right wrist is more readable to the sensors because of physical factors and this could vary by individuals.

    BTW, the free Cardiogram app on the iPhone shows some very nice charts now. I’m just using the free part of the app.

  25. Hello from Spain.
    Same here with my five series.
    Sent back to apple to repair and they say there is no problem with the watch.
    Very dissapointes since it is only four months ago. my old Garmin Forerunner never had this kind of issues.
    Maybe it is time to sell it and return to a real fitness watch.

  26. Same problem with my Apple Watch 6. Its now @ apple and they told me I’ll get a new one.. hopefully that one is better

  27. This may be a premature announcement, but since updating to watchOS 7.5, I have not had a problem with my Series 3 Watch recording heart rate reliably for the last ten days I’ve been running. Please share if this OS upgrade did or didn’t solve the problem for you!

  28. I have an Apple watch 6 with same issue for 8 months. Today was the first time it read correctly my heart rate for a whole run. What I did was:
    1. shaved my wrist where the sensor touches my skin. (I’m part wookie)
    2. wore long sleeves over the watch. run temp was 48 F
    3. Wore the watch as close to my hand as possible….NOT back towards my elbow
    4. less arm movement when running.
    5. I disabled the auto-pause.
    Not sure if it was one or a combination, but it worked. Thanks for all above

  29. I also have this issue I started my walk app but even before I started walking it said it was 150bpm which is was not I would have felt that just standing around … also it only lasted there for 5 seconds then dropped to 85 bmp obviously not right I have also called Apple have had tickets with no resolution when I wore my Fitbit I had less problems but the Apple Watch is expensive so I would think they would want to help seems like a lot of ppl have the same problem

  30. Bought my Apple Watch 6 in April 2021 and have just discovered that the heart beat monitor skips periods of 5 minutes during cycling workouts. Always when I have upped my work rate significantly. (Eg when attacking a hill).
    Very annoying, as it is just these sections of the workout I need to analyse!

    1. Hi Roger,

      Your experience mirrors mine. It’s so frustrating.

      In June I posted a comment about my experience that my watch began to record my heart rate reliably right after I upgraded it to watchOS 7.5. However, this did not last long. But the same temporary improvement occurred when I updated it to watchOS 7.6.

      For both these upgrades I had to do the entire backup -> reinstall OS -> restore from backup process, since my Series 3 watch didn’t have enough memory to do the upgrade “in place”.

      So my current theory is that there’s some kind of memory management issue on these watches that is temporarily cleared when the watch is reset with a fresh copy of the OS.

      However, I don’t want to reinstall watchOS every couple of weeks, so the problem remains.

  31. Excellent article, Adrian.. and I’m reading this exactly 2 years from the date of publishing. (Happy Birthday?)
    I have a series 3 and was beginning to give up on it since I faced the same issues in the last 3-4 months. This was both on treadmill and outdoor runs. Since this is an older model, I don’t have enough memory and refrain from upgrades. But let me try that first and then revisit the post. Surely, something will work!

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