Heart Rate Way Wrong

This is my second post about this device and I'm starting to scratch my head about why I spent the money.

I worked out this a few mornings ago-- hard rowing workout. My HR was recording a BPM of around 90 -- way, way lower that it actually was. My actual HR was around 150-160.

Last night I took a really brisk walk, including up a long hill. 5X+ showed a heart rate of between 59 and 65. Actual HR was around 110.

So what's gives?


Any ideas about why this would be so far off? I selected the "row indoor" activity, obviously. I tried both wrists.

Between this giant inaccuracy and the useless (and very misleading) sleep tracking, I'm starting to think this device is no good.

? Things can't be this off.

  • here is also something I posted in the past:



    I had the problem sometimes, that the HF sensor seems not to be able to read the HF anymore. The HF drops to 60, while the real HF was actualy above 100. A restart of the watch did help and the HF sensor was working again. So I actually wanted to have an alert, if the HF drops unusual low for that activity just to be alarmed, that there is something wrong with the HF sensor.

    I know all the discussions about the wrist HF accuracy and I even use am external garmin strap for strength training and indoor workout. This dropout of the wrist hf appeared till now only during hiking and only sometimes. I was on a 12h hike, without any dropout, but had some drop outs during some shorter hikes, so it is a bit difficult to tell from where it might come from. Especially as I do not change the position of the watch on the hand and a restart gets the hf sensor going again.....so therefor I thought it would be helpful to have such an alert for testing.....
  • I have a suspicion that the sensor/software sometimes get a false «lock» on half or double the actual HR, i.e. showing 120 when it’s actually 60 or vice versa.
  • I played around a bit during the 45km hike today and it seems, that the 5x plus is far more sensitive regarding the position, where you wear it and the tightness of the strap than it was my old Fenix 5. I got the best results via wearing it more high on my arm towards the elbow, about 1cm above my wristbone (yeah, I know, as described in the user manual) and using the right strap tightness, which us pretty tricky. If it is too loose, it will not work, but also if it is too tight it does not work.

    I tend to wear my watches more on the comfortable side during the day, not really loose, but also not too tight, hard to explain. So during hiking, that hands are hanging down and they are swinging, so they are starting to swell, which us pretty normal, especially if it is hot climate. So if the strap was snug first, it is getting uncomfortable and if I wear watches to tight, my arms start to hurt, so at the end of the day, I found a position and tightness, which brought a reliable HR reading, I'm just think, that next time I will simply using my chest strap as I do not want do spend so much time in finding a position where this sensor does work properly.

    I can understand that the sensor does mess up the readings, when the watch position is not ideal, but why the hell does it work again for some time, after restarting the watch without changing the position. It seems the sensor readings get stuck, if it is unable to read properly.....
    And the other question, if I wear much looser during a normal workday, why do the readings over the whole do actually look pretty ok. When I'm moving HR goes up, when I'm not moving it goes down again. It can be checked pretty good in the all day stats.......or does it have todo with the way the arms are moving during long walks.....

    I'm just annoyed a bit, enough to rather use a chest strap, I want to have working and reliable technology, which does support me and not filtering out how I need to wear it exactly that it works during an activity....and again, I know the technical limitations of optical HR, I'm just surprised about the much higher sensivity of the Fenix 5x plus compared to older models.....
  • I've had tons of problems with the Fenix 5X (Plus and not-Plus) in regards to heart rate accuracy. Garmin has replaced several of my previous Fenix's due to absolutely terrible HR accuracy. In fact, I just had my Fenix 5X Plus replaced this past week. I ride frequently on an indoor bike trainer, and wear two heart rate monitors (the Fenix, and either a chest or optical arm band). The Fenix is ALWAYS the loser. And keep in mind, an indoor trainer is the absolute easiest and best chance for the Fenix to shine... indoors with very very little arm movement and no vibration from running/walking/swimming/outdoor cycling.

    That said, here's a typical graphic of the Fenix 5X Plus (in green), compared to a far more accurate HRM (in this case, the Scosche Rhythm24, shown in red). The Scosche perfectly aligns with my intervals, while the Fenix stays artificially high through my rests, and inexplicably as soon as my actual HR starts to go up again, the Fenix plummets and catches up again. This strikes me as a software issue, but who knows. Oddly enough, the first ~13 minutes of the workout have the Fenix performing rather well! Even the slow uptake on the first main interval around minute 16 is somewhat forgiveable, considering the latency of reading the HR at the wrist versus upper arm. The remainder of the workout is completely unacceptable though. I ended the workout with a cool down and a final HR of around 110bpm; the Fenix was still reading above 165bpm during the entire cool down.ciq.forums.garmin.com/.../1472276.jpg
  • jmv_colorado not surprising really that the wrist based device is always the loser that's exactly what you'd expect. Do you grip the handlebars or just rest your hands on them?

    I'm sure software plays a big role and the various tweaks done give improvements for some people/activities and make things worse for others. If you are training by HR the surely a chest strap is the way to go recording based on electrical impulse as near the source as possible unless you have an overriding reason not to wear one.
  • JSRUNNER_ "That's exactly what you'd expect" ... when we as consumers have finally adjusted our expectations WAY down the totem pole. "You bought a top-of-the-line fitness device and expected all of the features to work? Hahahahaha!"

    The prices and marketing around these high-end devices is not inline with the real world results. The $2500 MARQ series with a WHRM that performs worse than the Fenix 5 Plus-series?! C'mon! The optical wrist heart rate monitor (either via software/firmware/hardware/physical body position) is little more than a novelty feature on an $800 device. We all know it, and we all complain about it, BECAUSE IT SHOULDN'T BE LIKE THAT! It works okay sometimes, it's completely awful other times. So what exactly is the point of it? How about we remove it entirely, everyone agree that WHRMs suck, and drop the price >$100 minimum?

    And no, it doesn't matter how I hold the bars. In this last example I posted, I varied my position a bunch during the rest periods, just to see if it was a physical body thing on why the Fenix HR measurement wouldn't go down. I moved my hands on the bars, I flexed my fingers, I even sat completely upright, and rested my arm horizontally across my body, and at one point rotated the watch around to the under-side of my wrist.... no change. It just happily plugged along at 170bpm the entire time.

    And yes, for any training or rides I do, I wear a secondary HRM. Obviously I do, as you can see I compared data to one. My point is that we shouldn't have to. One HRM should be enough.
  • And yes, for any training or rides I do, I wear a secondary HRM. Obviously I do, as you can see I compared data to one. My point is that we shouldn't have to. One HRM should be enough.


    I think the problem here is that you compared one Optical HRM with another Optical HRM - your Scosche Rhythm24.

    If you want to see which one is closer to correct, you should compare to a chest strap which measures electrical signals, not optical.

    I'm pretty sure Garmin uses software to modify the raw input to the OHRM which could induce unwanted results under certain circumstances. I'm also pretty sure your Scosche Rhythm24 also uses software to "profile" the output - witness the four "modes" that are user selectable.

    A chest strap avoids the interpretation/modification and just reports direct heart rate (and heart rate variability) data.

    Without a chest strap for comparison, I suggest that both your results are suspect.

    HTH
  • Former Member
    0 Former Member over 5 years ago
    jmv_colorado . Did garmin send you brand new or refurbished 5x+ replacements? Did garmin pay for the shipping?
    I previously had a 5x that created a hr graph like the one you posted or maybe a little better. I switched to the 5x plus and it is at least 50% worse. The only time i would trust the hr reading is if I am sitting doing nothing.
    If garmin did pay shipping and send new not refurb watch any suggestions on how to go about it. I do not want a refurb.

    thanks