Heart Rate inaccurately low during almost all exercise

I notice that at rest and throughout the day and night my Instinct 2 Solar accurately and frequently monitors my HR, and I love the resolution and function of this. However, during all activities (the reason I bought the watch), my HR is consistently low, either half of what it really is or a solid 30-50 bpm down from my actual HR. 

My primary activities are backcountry skiing, stairclimber, trail hiking / running, and in general activities that involve sustained HR near or at my aerobic max. I will be traversing a steep up slope on skis and feel my heart hammering, take a timer measurement on my wrist and count 180 bpm, only to see my watch clocking in at 130 realtime. I have done this in multiple conditions, including while maintaining full cardio load, and coming to brief rest to measure. This dramatically alters my calculated loads for these activities on Connect and Strava, which defeats the purpose of monitoring vitals for technology informed training. 

I have gone through all of the garmin support articles and suggested fixes, I have even shaved my entire wrist to get a better fix on the sensor. I have experimented with every position, orientation, and tightness, and switched wrists.

The only thing that has worked inconsistently is letting my HR come all the way down to rest, and then ramping it back up again. From a signal processing standpoint, It's almost as if the HR sensor signal is aliasing until the HR frequency jumps under Nyquist. But this fix does not work consistently, maybe 30% of the time, and man does it kill a good workout. 

I have had an instinct 2 for several months now and this is becoming a deal breaker, and I may see myself go back to Apple as a result (watch ultra). I love almost everything about this watch, but I feel like, how can they not get this one core thing right? 

Has anyone else run in to this consistently? Does anyone from Garmin have any further suggestions other than the boilerplate support links? 

  • Or call up the HR widget.

    Just did 20+ squats with Crossover Solar and LEDs continued flickering. It was not until I opened HR widget that LEDs went solid and HR instantly jumped 20 or so beats. Move IQ on. Shrug

  • Or call up the HR widget.

    The HR widget times out after 2 minutes, and returns back to the watchface, so not that much useful for anything longer.

  • Bought an Instinct 2 and I have the same problem.

  • I have noticed that my Crossover does these kind of abrupt changes in the measurements. Nothing really changed in the actual run, but the measurements bumped up 30-40 bpm, and this is not a unique case.

  • Have same problems from time when upgraded to firmware 16.10, and problem not fixed in 16.11. 

    Today my crossover (FW 16.11) registered averege heart rate 96 BPM during all exsersize. it is wrong measurement.  It must be 140-145 BPM

  • This is still a problem on the Instinct 2. Cheap devices like Pinetime and $25 knock-offs don't seem to need "activity selection" input to deliver HR consistent with chestband monitors for all activities and transitions in between, and actually selecting an activity doesn't seem to fix it, so I guess I will be wearing two watches like a dufus unless and until the Instinct 2 software gets fixed, since every other feature on the Garmin is working great. It kind of makes me wish I'd just replaced my 21-year-old solar G-Shock with a newer model when it finally died instead of a Garmin, though. I guess I'll give it a few more months for possible fixes before deciding whether to just resell it and brand switch. I really want to love this watch. Plz, Garmin.

  • Same issue here as well. I tried removing and rebooting the watch and still did not solve the issue. Then I started a new run, and after 8 minutes my HR magically jumped from ~140 to ~ 170. 
    In most of the other activity, I think it is accurate, but in high intensity workouts I almost always have those problem, and it is a major deal breaker!

  • Likely a software problem from a Garmin update.  I have had an Instinct for over 4 years.  About a year after buying it, it suddenly developed a problem keeping track of my swimming laps.  After months of conversations and two updates, Garmin finally fixed the problem which was caused by a flaw in one of its software updates.  I now have the same problem with the heart rate measurement that everyone is reporting here, but for the first years of ownership my Instinct did not have this issues. Ergo, I suspect the cause is likely a flaw in one of Garmin's updates.  

  • Hmm, I see I'm having similar issues with heart rate accuracy

    I noticed that during a run it'll suddenly jump to like 180bpm. Yesterday the watch claimed I spent 40 minutes of my run in zone 5 which is highly unlikely. This isn't the first time this happened. Now I see that some people say it could be related to a software update. I'm on 16.11

  • Same behavior here, last run activity:

    Medium running pace in the screenshot was 5:30, but after 1:08 of running time heart rate started decreasing while running pace remain the same, or faster. It's impossible that with constant effort after 1h of run heart rate decrease that way...

    16.11 firmware here