HR readings on multisports — TomTom Community

HR readings on multisports

Sierra26Sierra26 Posts: 4 [Neophyte Traveler]
edited January 2019 in Runner & Multi-Sport
The pulse shows just awful. What happens in a sitting position the pulse 200, but it happens in sprints 140. Have tried everything I can think of: 1) Tightened the strap 2) the bore in the other arm 3) to flip the watch 180 degrees 4) gave the watch to another person. It did not help. Please tell me they can (optical heart rate monitors) and should work. If possible could you share your results for comparison work. Forgot to say I have a Tomtom runner cardio white red. Thanks in advance.


  • tfarabaughtfarabaugh Posts: 16,851
    When worn properly the watch should be relatively accurate for most people but some physiologies will be less accurate - skin tone, arm hair, tattoos, etc. all play a factor. It is simply the nature of the technology, which is not perfect. The watch needs to be worn rather tight (but not to the point of uncomfortable) and needs to be worn much higher up the wrist than a regular watch (about 1" above the wrist bone). Any light seeping under the band will cause interference. You also need to let it settle down before using. When you first go to an activity screen you will notice the HR pop up, but it will be light gray. Once it has established a strong signal it will get bolder, which is an indication it is ready to go.

    Spikes in HR are generally from poor blood flow producing weak pulse strength or a loss of signal, 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. It sounds like you tried it but you can also try switching wrists and the position on the wrist. I find I got better 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. It also helps if you warm up a bit to get your blood moving and your HR up so it is producing a strong signal. 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.

    If all else fails, call Customer Support an d they can investigate if it is a hardware issue that needs replacing. To get the number for Customer Support, go to, choose Contact at the bottom, select the service required and the product name and click Contact Customer Care and then Phone Us. It will give you the phone number for the country your account is registered under (this can be changed by clicking the flag icon in the bottom right corner of the screen).

    I hope this helped answer your question. If so, please mark it as a solution so others can look for it if they have the same question.
  • Sierra26Sierra26 Posts: 4 [Neophyte Traveler]
    a little translation is not clear. But what you have described it is. When I stop at 20-30 C, the pulse becomes normal (measured by hand - same). But it is impossible to keep a pulse (for example 130 beats/min), he jumps. I noticed (as you say) that the clock is adjusted to the frequency step, under finger strikes. I bought a watch with an optical heart rate monitor to not wear a chest heart rate monitor, and it turns out now that will have to buy a chest heart rate monitor. Below I enclose a comparison with a chest heart rate monitor Suuanto.
  • Sierra26Sierra26 Posts: 4 [Neophyte Traveler]
    I took off the watch from your wrist, the watch will continue to measure the pulse.
  • Sierra26Sierra26 Posts: 4 [Neophyte Traveler]
    The figure shows that there were different intensity runs and stops, but the monitor was not able to catch my pulse.
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