why am I getting regular upticks in stroke rate during my rowing activities while using a fenix 7s and a garmin HR chest strap

I get regular upticks in stroke rate while using my watch during rowing activities.  It has started about 2 months ago and I cannot figure out why it is doing it.  the upticks are regular and the same magnitude.  They are not natural and not associated with my rowing during the activitiy - they are regular and significant jumps in stroke rate and i and my crewmates would notice if this was actually happening.  I recently upgraded to fenix 7s from forerunner 735 and it is still doing it.  What could be wrong?  I am not sure how to upload a picture of an activity graph here.

  • Hello,

    Do you wear your watch on your wrist or is it attached to the boat ?
    Is the watch strap tight on the wrist ?
    When rowing, is the boat stable ?
    Are there sometimes parasitic movements of the boat which could be misinterpreted by the accelerometer ?

  • Hi,

    I wear it snuggly on my wrist. The  boat is pretty stable.  I am not sure what you mean by parasitic movements of the boat, but because the upticks occur at regular intervals and also are the same magnitude, it makes me think they are some kind of artifact.


  • Indeed, you are right, the increases are too regular and are also of the same magnitude, so it cannot be because of jolts in the boat, due to different ways of rowing between crewmmates, for example. That's what you said in your message. ;-)

    If I understand correctly, you already had the problem with your forerunner 735 ?
    Do you see the same thing during an indoor rowing activity ?
    Have you updated your watch to the latest 10.43 firmware ?

  • Hi

    I haven't noticed it during an indoor rowing activity. Yes I have the latest firmware. I also tried changing the satellite system from GPS only to all systems and back. Not sure why this is happening and it is quite frustrating!  there is also an NK stroke coach in the boat which also acts as a GPS reciever - do they interfere?

  • I get the same thing, check the graph against time, mine are exactly 1m 30s apart. I guess it must be a feature of the app.