Polar M430 – Initial thoughts on Accuracy


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Last Updated on 16 January 2026 by the5krunner

Small things I always use

Watches and sensors

On the bike

Home and indoor training

  • NPE Runn: Makes my basic treadmill smart, sending more accurate speed and distance to my watch and Zwift. I use it.
  • Google Wifi: Keeps Zwift connected in my pain cave. I use it.
  • Apple TV 4K: Zwift on the big screen. I use two.
  • Google Nest Doorbell (wired, 2nd gen): My video doorbell, running in both Google Home and Apple Home. I use it.

Health, recovery and sleep



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6 thoughts on “Polar M430 – Initial thoughts on Accuracy”

  1. im pretty sure stryd support will show up soon on this watch. it´s a runners watch and i´m pretty sure upcoming competitors will have these features (FR 245 etc)

    1. I hope so for polar.
      but for garmin its not straightforward…think power zones, all the averages and power alerts. it’s not just that they already have ciq data fields showing. polar still haven’t got all the peripherals firmware bits fully working/integrted

  2. After years with S625X I bought M430 in January. I have a problem with optical HR accuracy. I have a conversation with Polar support, check many sites searching for the solution, but nothing helps. M430 simply isn’t accurate at the beginning of training.
    I wrote my (honest) review with the video which shows the problem and compares optical measuring HR and strap measuring HR.
    Here is my problem which should check every potential buyer:
    http://kacnje.blogspot.com/2018/02/polar-m430-unusable-optical-heart-rate.html

    1. optical HR varies from person to person.
      you may well have serious problems with one watch and someone else will find it works 100%…it’s the way it is from all vendors with all tech on the wrist
      arm worn sensors are much better but some people still have problems there too

  3. I have exactly the same problem as Iztok. For the 1st 7 to 30 minutes hr stays way low then suddenly jumps to correct level. Also at the end of a training session the hr often stays incorrectly high for 10 minutes and then suddenly drops to correct level. When used with a strap it works fine – but that kind of defeats the purpose of the watch!
    Others on the net report the same problem – Polar needs to fix this

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