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Sudden drop of HR when switching HRM Chest strap -> OHR Sensor

DPSK
over 4 years ago

I have the HRM Tri chest strap.

I notice after saving an activity, the HR drops all of a sudden when switching sensors from HRM chest strap to watch OHR.

For example,

Current HR is 110 after warm down

Save and exit the run activity on the watch

Current HR becomes 70 all of a sudden

Takes some time for HR to rise again

Anyone notices this bug ?

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  • 0 over 4 years ago in reply to jmto
    jmto said:
    I don't follow.. Main screen? So you have a watch face that shows HR? And you look at your recovery HR from there? Well, your recovery hr process is that is to blame here.

    Agh ok sorry maybe I wasn't clear on the 1st post.

    My concern is the sudden drop in HR on the HR Details of the Garmin connect app.

    The chart where it shows the HR graph for the whole day.

    Also, your watch is showing a sudden drop of HR to 70 or 60 after saving the activity.

    I guess not critical enough to consider as a bug?

  • 0 over 4 years ago in reply to DPSK
    DPSK said:
    I guess not critical enough to consider as a bug?

    If you think it's a bug, report to Garmin. This forum is not for reporting bugs.

    I don't still understand what your issue is... You mean graphs like these?


    I don't much see a problem with these.. Could you show example? And if that graph have some error like you are saying, it won't affect your Resting (bpm) or High (bpm), I'm still puzzled what does go wrong because of that.

    So it sounds like maybe some small "beauty" error, which doesn't affect anything else than that graph itself.

  • 0 over 4 years ago in reply to DPSK
    DPSK said:
    Agh ok sorry maybe I wasn't clear on the 1st post.

    I follow what you're saying. The strap is measuring electrical signals where the WHR is using light measuring blood flow. In a perfect world it would be nice if the WHR started where the strap left off but because they measure diffently this is not the case.  I believe Only Two is correct when saying the "default" HR reading when the WHR is activated is 70.  I've noticed what you have also, but it only takes my watch 5-10 seconds to catch up to my correct HR.  This can be avoided if it's a concern for you to wait until your HR drops back down to roughly 70 before switching back to the WHR. 

  • 0 over 4 years ago in reply to DPSK

    weird - I wear my HR strap every day for run's or rides - I don't see any blip that would point to this on the graph.  It is smoothed and you can't zoom into the few seconds anyhow.  So not even a graph/data cleanliness issue ("beauty").  The App is a bit more jagged, but still shows a slow dip to 85ish...  eventually driving down after shower and sitting down.  

    The App graph is so gnarly up and down at times (whether by error or due to standing/stairs/sitting/couch/stairs...etc..(see jtmo's images). hard to worry about the 5-90sec dip right after a workout anyhow (IMHO).)   (not that I see it personally...?)

    Now during a workout... thats a different story!  I'm all about clean and 'beautiful' HR graphs...lol   especially during strong important workouts, whats better than a good warmup, then a strong 3x10' hill climb treadmill workout w/ 3min recoveries... good stuff!  lol - but I'm a data dork. Sweat smile

  • 0 over 4 years ago in reply to tess
    tess said:
    The strap is measuring electrical signals where the WHR is using light measuring blood flow.

    OK fair points.

    tess said:
    In a perfect world it would be nice if the WHR started where the strap left off but because they measure diffently this is not the case.

    Yup this is exactly what I thought could be improved from the watch algorithm or software. Upon switching from Chest strap to WHR, the watch can "learn" from the previous HR data.

    tess said:
    I've noticed what you have also, but it only takes my watch 5-10 seconds to catch up to my correct HR.

    Really that fast for you? It is like a couple of minutes for me.

  • 0 over 4 years ago in reply to jmto
    jmto said:
    If you think it's a bug, report to Garmin. This forum is not for reporting bugs.

    woah I didn't know this forum is not for reporting bugs.

    jmto said:
    I don't still understand what your issue is

    I bet you don't look at the HR of your watch after saving an activity. Yeah then it is a non issue.

  • 0 over 4 years ago in reply to tess

    The other solution would be to enable Garmin Pay, so that the OHR remains active throughout your workout, even though the chest strap is the source for HR data.

  • 0 over 4 years ago in reply to mcalista

    Whats the reason? Enable GP so that the watch is awake all the time?

    I did enable the GP. Does it work for you?

    I believe the algorithm is as such: if you have chest strap connected, the watch OHR sensor is off?

  • 0 over 4 years ago in reply to DPSK

    I thought that was the Algorithm as well... however I have noticed slow connection to my HRM-Dual on runs and sometimes I don't think it alerted me it was connected (but it was, missed it, due to 'do not distrub' in early morning) and I lift watch and notice Optical is on... but end of run data is great and looks like strap data (smooth and on point).  I googled optical and strap on 945...  there seemed to be a lot of posts regarding watch using both (verification maybe?)  But I swear it isn't always on... so I don't know!!!!  lol

  • 0 over 4 years ago

    I noticed the same at my 735 with HRM Run. After the disconnect of the strap the HR drops 120-130 to sometimes 50-60.