TomTom Spark + cardio heart-rate too high

bimella4
bimella4 Registered Users Posts: 3
Apprentice Traveler
edited January 24 in TomTom Sports
Hi I just got a Tom Tom Spark + cardio but am finding the heartrate monitor innaccurate. When I go on a long run and can talk comfortably, I look at my results afterwards and it says I was working in the speed and sprinting zones. I never seem to be working in any other zones even during an easy run. This can't be right.

Comments

  • tfarabaugh
    tfarabaugh Posts: 16,943
     Superuser
    bimella4 wrote:
    Hi I just got a Tom Tom Spark + cardio but am finding the heartrate monitor innaccurate. When I go on a long run and can talk comfortably, I look at my results afterwards and it says I was working in the speed and sprinting zones. I never seem to be working in any other zones even during an easy run. This can't be right.

    Prolonged spikes in HR like that are generally from poor blood flow producing weak pulse strength, so the watch reads cadence instead. This is particularly apparent early in a workout or during a non-intense workout when you are not warmed up. You have to think of the optical heart rate as an algorithm that is attempting to track a signal in a set frequency range (30-230 or whatever it uses). If the pulse signal is weak it latches onto the next strongest rhythmic signal, which is your cadence in running and the vibrations of the bike in cycling. For most people who experience this while running it spikes to around 180-200 bpm which is also the average cadence people run at. Additionally, each person has a different HR signal ‘strength’, depending on a range of factors, so some are prone to get it more than others. But usually their signal strength is lower for the first 5-10 minutes until they warm up properly. So in that time, it is prone to latching onto cadence, which is a common fault with all optical HRs, unfortunately. If you notice it while it happening you can try moving the watch a bit or briefly pausing your run so it loses the cadence reading and latches back onto HR, which I find usually corrects it. I generally pause the watch, stand still for 20-30 seconds and will see it immediately start to drop. Once it gets into a more reasonable range and the pulse reading stops dithering (dithering is when it is not getting a good signal and it is a lighter grey in color) I start up again and it stays true for the rest of the run. You can also try switching wrists and the position on the wrist. I find I got getter readings on my right wrist over my left and some people find they get better readings if the watch is on the inside of the wrist rather than the outside. Play around with it and see if any of this helps you. The challenge for the manufacturers of optical HRs (and this is a common issue with all brands, my Scosche also does it) is to figure out how to factor out the other "noise" that is overriding the pulse signal without also factoring out other important data.

    I hope this helps, please let me know if this answered your question. If it did, please mark it as a solution so others can look for it if they have the same question.
  • bimella4
    bimella4 Registered Users Posts: 3
    Apprentice Traveler
    Thanks so much. That makes sense
  • tfarabaugh
    tfarabaugh Posts: 16,943
     Superuser
    bimella4 wrote:
    Thanks so much. That makes sense

    Glad I could help. Try moving the watch around (other wrist, inside of the wrist) and try warming up a bit before starting it up. All might help alleviate it a bit. When you get a chance please mark my response as a solution so others with the same question can look for it.
  • bimella4
    bimella4 Registered Users Posts: 3
    Apprentice Traveler
    Great! Thanks. I can't see where to mark it as solved
  • tfarabaugh
    tfarabaugh Posts: 16,943
     Superuser
    bimella4 wrote:
    Great! Thanks. I can't see where to mark it as solved

    You should be able to go to my first response and there is a "Mark as Solution" button. It may depend if you are on via PC or mobile. If you can't find it, don't worry about it, one of the mods will probably take care of it.
  • nivja
    nivja Registered Users Posts: 7
    Master Explorer
    Hello all,
    I started a similar discussion a year ago: https://en.discussions.tomtom.com/spark-and-spark-3-runner-2-and-runner-3-473/tomtom-spark-heart-rate-too-high-first-10-minutes-of-running-993205/index1.html#post1044818
    I marked an answer as solved, because I believed from the reply that Tomtom was working on it to get it solved. However, it is not solved. I might just as well still use my previous running watch without HR. It would have saved me a lot of money because the Tomtom's HR is completely worthless.
    So my advice: do not buy the product if you want to use HR while doing an activity because the first 10-15 minutes it is completely off, as in always way too high.
    Tomtom please fix this or stop selling the products.
  • Arvjan
    Arvjan Registered Users Posts: 8
    Apprentice Seeker
    nivja wrote:
    Hello all,
    I started a similar discussion a year ago: https://en.discussions.tomtom.com/spark-and-spark-3-runner-2-and-runner-3-473/tomtom-spark-heart-rate-too-high-first-10-minutes-of-running-993205/index1.html#post1044818
    I marked an answer as solved, because I believed from the reply that Tomtom was working on it to get it solved. However, it is not solved. I might just as well still use my previous running watch without HR. It would have saved me a lot of money because the Tomtom's HR is completely worthless.
    So my advice: do not buy the product if you want to use HR while doing an activity because the first 10-15 minutes it is completely off, as in always way too high.
    Tomtom please fix this or stop selling the products.
    I had the problem you describe too for about 2 years. It finally became clear to me that the high heart rates measured were a result of the way I had been wearing the watch.

    Somewhere on the forum I read something like 'don't wear the watch on your wrest bone'. I didn't know exactly what was meant by that. But I tried attaching the watch somewhat higher on my lower arm. Where the arm is a bit 'meatier' as to say. That worked alright for me. I now no longer have increased heart rate readings (which used to be sometimes well above 200).
    I think the heart rate readings can be less accurate in case the user's arm is skinny, like my arm is.

    I think the TomTom watch is a pretty good GPS watch, with very solid quality. But it seems rather hard to find out about how to use the watch to avoid false heart rates. Maybe because TomTom has not tested the watch on anyone with skinny arms? I don't know but attaching the watch slightly more in the direction of my elbow (just a 1-3 cm's) seems to do it. And the watch also has to be attached not too loose around the wrist. That is, in my case.