Related

Reduced heart rate readings during activities

eeyou
over 1 year ago

Hi.

I've seen quite a few threads here regarding inaccurate hear rate readings, however, they don't seem to be describing exactly the weirdness that I'm observing.

General description: the watch (Venu 3, primary wearable) is reading way lower heart rate values during activities, when there is no activity being recorded on the watch.

What's happening: I do indoor cycling on Zwift using a smart trainer, I have Garmin HRM-DUAL heart rate chest strap paired with the trainer (this is where Zwift gets heart rate readings from), activity is recorded in Zwift and when finished riding Zwift exports the activity to Garmin Connect. Venu 3 is not used at all for the activity recording, it's just idling (in smartwatch mode). During the ride, the watch will consistently read far lower values than the values I see on Zwift from the chest strap.

For example, here's heart rate chart from an activity, that got imported from Zwift (i.e. readings from the chest strap):

And this is heart rate chart from day summary page on the day of the activity (i.e. readings from the watch):

Starts at ~88bpm, peaks at 111bpm and ends at 97bpm - way-way off from what the strap recorded. With sudden heart rate surge right after the activity...

Now, I can understand, that the watch probably has reduced sampling rate in "resting" mode (i.e. no activity being actively recorded) to save on the battery, so as an experiment I tried few times forcing the watch into "active" mode by recording simple "Cardio" workout at the same time as Zwift is recording the ride, and this results into matching data:

Heart rate from an activity from Zwift:

And from day summary page (obviously, some data aggregation happening here, but it's in the same ballpark):

I'm trying to understand whether there is any issue here with this heart rate discrepancy, could it lead to incorrect calculations of other metrics that rely on heart rate data...

I believe it does? For example, on the weeks when I do not use this "Cardio" workout "hack", I struggle to reach "intensity minutes" target. But doing the "hack" at least once easily fills the circle., and "vigorous minutes" are used in "fitness age" calculations...in fact, ever since I caved in and started Zwifting my fitness age value has returned to my real age (used to be 3-4 years lower). Wouldn't be surprised if VO2 Max estimations are also inadequate because of erroneous heart rate data...

I'm hesitant doing this "hack" all the time (even if immediately discarded when stopped recording), because now it could lead to sort of doubled amount of activity and throw calculations off again but to the other extremum?

Is there some setting I could tweak on the watch to have the watch realize I'm actually doing a workout so it needs to read heart rate more frequently without actually starting a workout on the watch?

  • 0 6 months ago in reply to attackuntiltheycrack

    I agree with everything you said here (and no, it doesn´t seem like any of the health metrics are affected by workouts not actually recorded on the watch, so uploaded from zwift and or from strava doesn´t affect body battery, stress and so on). Now if only there was a way to convince Garmin that this is actually a complete *** show as a general fitness and health device... Sadly, they seem to think this is not an issue at all. And the frustrating thing is this could easily be fixed by them in software and is not really a problem with the hardware at all...

  • 0 6 months ago in reply to 2679107

    The False Heart Rate Detection advisory is just ludicrous. Why is it that if I start an activity on the Venu, the HR is correct, but if I don't, it's just some BS? Throughout the day, it also is capable of showing the HR. This is a major issue because this means the whole metrics like Body Battery and so on are just BS. That said, the whole reason of wearing the device becomes useless because the data is wrong

  • 0 6 months ago in reply to attackuntiltheycrack

    Indeed it is ludicrous, and yes as a general fitness device that passively monitors your body metrics the venu3 is basically useless. 

  • 0 6 months ago in reply to 2679107

    The Venu 3 has some serious bugs because I have found the following issue. I went for a quick walk, and no, I did not start an activity because i just walked around the corner to the store. It seemed to be showing accurate HR data. I returned to my desk, sat down, and the watch was locked into a heart rate of 93. I thought, "This cannot be right," so I used another device to check, and it was 61. The Venu 3 just froze at 93 and actually recorded that for 2-3 minutes. It did not drop until I opened the HR app on the Venu, then it went back to normal.

    This just shows me that the device cannot be trusted. 

  • 0 5 months ago in reply to 2679107

    I came here to see if the Venu models have the same HR sensor problem as the Epix Gen2 that I have. With the Epix, in an activity the HR is way off (ie. 76 vs actual 145). It's not all the time. In fact, more than half the time it works well, and sometimes it self-corrects after about 10-15 minutes. Sometimes never. Sometimes doing a hard reset corrects it immediately. Sometimes not. None of Garmin's suggestions work.

    The issue, of course, is that when it malfunctions, and it does so often, it throws off all metrics downstream of heart rate -- VO2max, Training Load, Training Readiness, Intensity Minutes, Training Status, Acute Load, Calories, Load Focus, Exercise Load, Stress, Body Battery. In short, everything you pay $1,000 to get in the way of sports metrics.

    I'm not sure if the problem you describe is the same one that many Epix owners have, as you say the HR sensor works well during an activity, as that is precisely when it fails on the Epix.

    At this point, I'm trying to decide whether I should abandon Garmin entirely and find a sports watch that works.

  • 0 5 months ago in reply to 7017726

    FR(265s) user here and I have the issue you describe; the HR being innacccurate tracking an activity. I worked around it by just using either a chest hrm or by doing the activity and just not tracking it, so at least my HR is accurate & just add in a manual activity. So, really annoying.

    My garmin just updated (20.29) last night and I did a tracked run this morning without a chest hrm and it seems fixed?! 

  • 0 5 months ago in reply to 7017726

    Personally I´ve never experienced any issues while actually having manually started an activity, the HR readings for me have been pretty much spot on. Unfortunately it is garbage the times you forget to (or by accident fail to) start an activity so the metrics you mentioned are quite often completely bogus anyways.