Runner 3 Music: Heart Rate drops at Interval Training

Bernd-SIN
Bernd-SIN Registered Users Posts: 3
Apprentice Traveler
edited January 24 in TomTom Sports
Hi there,

I have my Tom Tom Runner 3 Music now for about 8 months.

What I like about the Runner 3 is that it measures heart rate, has an integrated GPS, is watertight and allows me to play music without having to carry my phone around. One major reason to buy the watch was that the heart rate measurement should allow me to reduce my exercising effort in case my pulse gets too high.

Unfortunately, this is where the Runner 3 deceives. Every week, I do one hour bootcamp training and almost every time - while the exercises are getting more and more intense - my heart rate suddenly drops from 150/160 to about 90 or even 50 bpm. While my heart is beating to the rhythm of "Beat It" or at least 140 bpm and I start panting for breath, my watch shows me a pathetic 85 or 90 rpm or even 50 bpm ?!

Also, I find the calculated fitness points quite an encouragement to work out harder. But the problem is at 50 bpm you are “technically” at rest, so any effort you put into the exercise will be “lost”, at least for the records. So you can imagine my motivation “to give it all” when my watch tells me that I am resting ...

I have tried a couple of things, mounting the watch further away from the wrist, changing from left wrist to the right and back, but to no avail. Also, recently, I had my watch changed, but the new one shows the same problems. Did anyone encounter the same issues and found a remedy? I really would like to use the watch in a meaningful way, but it seems that the only way to do so would be to use a separate heart rate monitor to get it to function properly.

Comments

  • tfarabaugh
    tfarabaugh Posts: 16,948
     Superuser
    There are two issues with heart rate using optical HR monitors, and these are on all devices, not just TT ones: low heart rate and HR spikes. Low HR is often seen in rowing, cycling and weight lifting or anything with a lot of arm movement. Any time you do an activity that squeezes or tenses the forearms (like the pull stroke in rowing, bearing down on your handlebars in cycling, or virtually any weight lifting move) you are squeezing the blood vessels the watch is reading, so it sees this as a reduced pulse. It is not that the watch is having a problem reading your pulse; it is that your pulse at the wrist has actually dropped because you are temporarily cutting off blood flow to the vessels it is reading. And when the arm is constantly moving, like with kickboxing, the movement keeps jarring the watch, causing it to lose signal and drop out. I have experienced this with every optical HR I have used, including a Mio and a Scosche unit. For these sorts of activities you are better off using a chest strap synced to the watch if getting a more exact reading is important to you.

    As to the points, unfortunately it thinks your HR is low so you do not hit the threshold for points, but it should not take a watch to give you motivation. I honestly don't feel you can make any judgments from what it is telling you in terms of fitness points or fitness age. It only uses runs or cycles to calculate points and while it does refine its readings over time but it seems to be a random, capricious measure that ties to very little. It is based on whatever algorithm TT came up with, which is different than what Garmin uses or Strava uses, or anyone else. Ultimately I don't expect a watch to be able to tell me how fit I am.

    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.
  • Bernd-SIN
    Bernd-SIN Registered Users Posts: 3
    Apprentice Traveler
    Hi tfarabaugh,

    I don't know why, but I was pretty sure I would hear from you rather sooner than later ;-)
    I agree that optical HR monitors have their limitations but on the other hand the announcement that one could measure heart rate and do away with chest straps seemed to be a very appealing promise. I had read quite a number of reviews on fitness watches but none mentioned about the shortcomings of this HR technology.

    I would tend to disagree with you regarding the fitness level. While there is no absolute measure by using any algorithm that it is out there, sticking with one tool would give you some indication of relative performance over time.

    Again, this stands or falls with the ability of the watch to accurately measure heart rate during a training session without falling back to resting heart beats when you are exercising.

    My wife has a fitbit Charge2 and I am pretty impressed what that device can do on sleep tracking (TomTom sucks in this discipline). I will try it out next week to check its HR accuracy against the TomTom. If it performs I will switch to fitbit, if not I will have to get a chest strap. Can you recommend a brand?

    Thank you for sharing your experience.

    Cheers
    Bernd
  • tfarabaugh
    tfarabaugh Posts: 16,948
     Superuser
    Pretty much any BT chest strap will work, but some work better than others. Price seems to not be a factor as the cheaper ones often seem to work better than the expensive ones. This is due to the fact that cheap models are more likely to use the base BT protocols and not customize them for advanced features or settings like more expensive models do (and there is no way of knowing if a manufacturer has tweaked the protocols to take them out of compliance). The BT standard is in such a way a 'standard' that it can be widely interpreted with different settings for buffer sizes, time outs, profiles, protocols, antenna configurations, etc.. TomTom cannot change their code every time a manufacturers tweaks the BT coding. This is a case where paying more will not increase the chances of connectivity, it may actually decrease it. Make sure wherever you get it from has a good return policy.

    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.
  • Bernd-SIN
    Bernd-SIN Registered Users Posts: 3
    Apprentice Traveler
    Hi tfarabaugh,

    Thanks a lot you for your advice :)
  • tfarabaugh
    tfarabaugh Posts: 16,948
     Superuser
    Bernd-SIN wrote:
    Hi tfarabaugh,

    Thanks a lot you for your advice :)
    Glad I could help. When you get a chance please mark my response as a solution so others with the same question can look for it.