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Heart rate monitor on F235 is a disaster

Former Member
Former Member


Never buy a new model (experimental) product in its first year he keeps repeating in his head.....
The attached image is taken after running 10 times up n down the house staircase. You can see a comparison between the Forerunner 405 with chest strap and the Forerunner 235. My old trusted companion which i have had for 6 years forrunner 405 shows 143 bpm and the forerrunner 235 showing at the same time 112bpm. A whoping 30 bpm difference. Really feeling like i was sold an unfinished product Garmin

The HRM of the 235 is just unreliable and works only partially, hence useless
  • Former Member
    0 Former Member over 9 years ago
    How do you raise a ticket? I've been experiencing this cadence lock on most of my runs. Frustrating as I'd like to give training to HR a go but havent had one good session with this watch yet.
  • Former Member
    0 Former Member over 9 years ago
    Next was a cross country race - while it looks like it might be cadence lock, I would have expected HR and cadence to be in the same range for a lot of the race, although I can't be 100% sure - maybe it was for some of it and then it settled down.



    GC: https://connect.garmin.com/modern/activity/1010007916


    No offense but that is most definitely cadence lock. Your HR should and would never fluctuate 8 beats within such short periods of time at that intensity. Never! That HR track is garbage.

    As an example, here is a 10 mile race on Strava of mine : http://www.strava.com/activities/164629611/overview

    Mind you this was a 10 mile race so the time is much longer and the effort is even lower than your XC race yet my HR only fluctuated 3 beats during the entire race, that is how even the effort was. HR does not change as quickly and abruptly as your log indicates, that track does not represent anything of real value unfortunately.
  • Former Member
    0 Former Member over 9 years ago
    No offense but that is most definitely cadence lock. Your HR should and would never fluctuate 8 beats within such short periods of time at that intensity. Never! That HR track is garbage.

    As an example, here is a 10 mile race on Strava of mine : http://www.strava.com/activities/164629611/overview

    Mind you this was a 10 mile race so the time is much longer and the effort is even lower than your XC race yet my HR only fluctuated 3 beats during the entire race, that is how even the effort was. HR does not change as quickly and abruptly as your log indicates, that track does not represent anything of real value unfortunately.


    Here's the Strava link to the same activity http://www.strava.com/activities/467265623/overview

    No offense taken and I appreciate the feedback. I put those files and links up so others could see them and judge for themselves. You're just probably better at judging pace than me and definetely much faster!! Like I said I wasn't sure if it was or not, but there was quite a short, steep, muddy hill (about 10% gradient) that really knocked the wind out of me. 3 times. But if you look at the overlay picture you can see but the cadence and HR match exactly around where the x axis says 320. I was going at pretty much full effort for most of the race so HR and turnover was high which is why I was unsure whether it was cadence lock. (Top tip - don't run cross country without spikes - yikes!)
    Anyway, I think the cadence lock is much much clearer in the cooldown run - HR just jumps straight up to the 160s while I was just plodding around the roads during a cooldown and stays there even though I didn't break a sweat. Not good. Strava: http://www.strava.com/activities/467266525
  • Heart rate issues.......

    I'm a big fan of the 235...THERE I SAID IT hahah

    just thought i'd sahre this, run from the other night with some hill reps...

    Started the run using my garmin HRM strap, as i quite like it lol, however i think the battery has had it and its being playing up lately, see first 1mile 245 bpm! so i took it off and disconnected it, did the rest of the run with 235 on optical and quite pleased with the results,

    as you can see tracks my hill reps HR increase pretty well and does not appear to have any cadence lock issues, you can see one drop in HR prior to reps, one drop in the middle for a rest period and final a drop at the end for another rest period,

    would be curious to anyone thoughts on this run and the HR data!??

    FYI having used the hr strap with a FR15 and a FR 620 and now the FR235 i have a pretty good idea of my effort and HR and generally i'm pretty happy with how the optical heart matches that, like everything there is the odd anomaly but i have experiences anomaly's with the strap too!


    thanks!


    SCREENSHOT OF RUN

  • Former Member
    0 Former Member over 9 years ago
    I find for running and any other tracked activities the watch works great the majority of the time. I've said this all over the forum. I've probably only had cadence lock or dropped HR 2 times in about 30 workouts including weight training and bike.

    The key, as has been mentioned countless times before, is to wear it HIGHer and TIGHT. Before a workout, when you usually tighten the watch a notch or two, if you are having problems, tighten it by another notch. Make sure it's in that sweet spot past your wristbone but not so high up the arm that the forearm muscle can affect it.

    It's all about the watch and therefore the HR sensor not being able to move during your workout!

    On the other hand for activity tracking it's a piece of crap right now due to Garmin Connects bad server side software and the HRMs low sample rate / algorithm during non-timed general activity tracking.
  • How do you raise a ticket? I've been experiencing this cadence lock on most of my runs. Frustrating as I'd like to give training to HR a go but havent had one good session with this watch yet.


    See http://www.garmin.com/us/support/contact?#fragment-1
    Call or email them.
  • i think alot of people think they are having cadence lock when they arent!
  • i think alot of people think they are having cadence lock when they arent!


    I've been thinking the same thing lately.

    "Sometimes a cigar is just a cigar. -- S. Freud

    Yes, cadence lock is a real thing with optical HRMs, and it certainly does happen with the 235. It'd probably happen less if you move the oHRM off the wrist and further up the arm, and I imagine the Mio and Schoshe folks simply have more mature systems to sort out HR from all the other stuff. The optical HR trace is also pretty noisy (high variance), but that's an artifact of the technology and whatever smoothing Garmin is or is not doing to the signal.

    Let's not forget that we're measuring an effect (light reflectance changes) of an effect (skin blood volume changes) of an effect (pressure waves, after travelling down the arm) of the heart muscle contractions (heart beat). In contrast, a chest strap is literally reading the electrical impulses that cause the heart muscle contractions. Can't get much more direct without poking something inside. Is it any wonder that this physiological game of Broken Telephone isn't as accurate as an actual direct measurement?

    Just my opinion here, but if someone needs a low variance HR graph they need to stick to chest strap HRMs, or stick with a Mio or Scoshe worn well above the wrist, and preferably above the elbow. Same if you're doing short high intensity intervals, but be cautious in expectations due to cardiac lag; actual HR will lag effort a bit, and any HR measurement that smooths the reading (i.e. optical HRM) will add further lag to getting reading. In contrast, when you're looking for average HR and time-in-zone figures from your workouts, with in-workout guidance of effort (and can accept using your noggin to discern a real reading from a bit of noise), then the 235's oHRM does fine.

    The nice thing is the 235 lets you very easily use whichever you prefer for a given workout; if it sees an active paired ANT+ HRM it'll use that instead of the internal oHRM, otherwise it just uses the internal oHRM. So if you're going to do intervals, strap up and go. When going for steady endurance building runs just leave the (cold/wet) strap behind and the oHRM gets the job done.
  • I've been thinking the same thing lately.

    "Sometimes a cigar is just a cigar. -- S. Freud

    Yes, cadence lock is a real thing with optical HRMs, and it certainly does happen with the 235. It'd probably happen less if you move the oHRM off the wrist and further up the arm, and I imagine the Mio and Schoshe folks simply have more mature systems to sort out HR from all the other stuff. The optical HR trace is also pretty noisy (high variance), but that's an artifact of the technology and whatever smoothing Garmin is or is not doing to the signal.

    Let's not forget that we're measuring an effect (light reflectance changes) of an effect (skin blood volume changes) of an effect (pressure waves, after travelling down the arm) of the heart muscle contractions (heart beat). In contrast, a chest strap is literally reading the electrical impulses that cause the heart muscle contractions. Can't get much more direct without poking something inside. Is it any wonder that this physiological game of Broken Telephone isn't as accurate as an actual direct measurement?

    Just my opinion here, but if someone needs a low variance HR graph they need to stick to chest strap HRMs, or stick with a Mio or Scoshe worn well above the wrist, and preferably above the elbow. Same if you need super-quick reactivity to HR changes (short high intensity intervals). In contrast, when you're looking for average HR and time-in-zone figures from your workouts, with in-workout guidance of effort (and can accept using your noggin to discern a real reading from a bit of noise), then the 235's oHRM does fine.

    The nice thing is the 235 lets you very easily use whichever you prefer for a given workout; if it sees an active paired ANT+ HRM it'll use that instead of the internal oHRM, otherwise it just uses the internal oHRM. So if you're going to do intervals, strap up and go. When going for steady endurance building runs just leave the (cold/wet) strap behind and the oHRM gets the job done.


    Partly true, the only thing is that other devices have proven that oHRM CAN actually work pretty damn fine. (Again I come up with the TomTom cardio which does a pretty damn decent job). Unfortunately garmin had to go with their own sensor which doesn't work too well at all, for now at least.

    But I think that when you spend ~350 euros on a watch you are allowed to expect more then 'does decent on less demanding steady paced workouts most of the time...'. Let alone all the other issues people seem to be having. Just feels as if Garmin released a yet unfinished product (and unfortunately that is something more and more common nowadays).
  • I've been thinking the same thing lately.

    "Sometimes a cigar is just a cigar. -- S. Freud

    Yes, cadence lock is a real thing with optical HRMs, and it certainly does happen with the 235. It'd probably happen less if you move the oHRM off the wrist and further up the arm, and I imagine the Mio and Schoshe folks simply have more mature systems to sort out HR from all the other stuff. The optical HR trace is also pretty noisy (high variance), but that's an artifact of the technology and whatever smoothing Garmin is or is not doing to the signal.

    Let's not forget that we're measuring an effect (light reflectance changes) of an effect (skin blood volume changes) of an effect (pressure waves, after travelling down the arm) of the heart muscle contractions (heart beat). In contrast, a chest strap is literally reading the electrical impulses that cause the heart muscle contractions. Can't get much more direct without poking something inside. Is it any wonder that this physiological game of Broken Telephone isn't as accurate as an actual direct measurement?

    Just my opinion here, but if someone needs a low variance HR graph they need to stick to chest strap HRMs, or stick with a Mio or Scoshe worn well above the wrist, and preferably above the elbow. Same if you're doing short high intensity intervals, but be cautious in expectations due to cardiac lag; actual HR will lag effort a bit, and any HR measurement that smooths the reading (i.e. optical HRM) will add further lag to getting reading. In contrast, when you're looking for average HR and time-in-zone figures from your workouts, with in-workout guidance of effort (and can accept using your noggin to discern a real reading from a bit of noise), then the 235's oHRM does fine.

    The nice thing is the 235 lets you very easily use whichever you prefer for a given workout; if it sees an active paired ANT+ HRM it'll use that instead of the internal oHRM, otherwise it just uses the internal oHRM. So if you're going to do intervals, strap up and go. When going for steady endurance building runs just leave the (cold/wet) strap behind and the oHRM gets the job done.




    Very well said......that is exactly how i use mine, interested in 25/7 hrm and using it for some running particulaly a steady run but if i want to do intervals etc i just stick on the old strap, best of both!

    he comment that other companies do it better i think should be made more carefully.....TomTom for example have far less users can we be so sure their optical data is perfect?

    Just look at the mess fitbit is in currently over their optical sensors