Related
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Forerunner 245 Pulse Ox ridiculously inaccurate

Former Member
Former Member over 5 years ago

I bought a Forerunner 245 a few days ago and it nearly gave me heart failure when it shows my spO2 so low that I should be in hospital. It will show a reading of 82% while an oxymeter shows 98%. It it a faulty model or are the readings generally this bad? I have attached a reading that I have just taken compared to the oxymeter.

  • 0 over 3 years ago

    Yes I have the same issue. It can even differ by 10 % for 2 consecutive readings. I went to 100% too, and I didn't know it was possible. :o

  • 0 over 3 years ago

    There are no watches that have very accurate Sp02 readings yet, none of them are medical grade. Just google "sp02 watch inaccurate" and you'll find tons of articles for many different watches and how their spo2 readings are inaccurate.

  • 0 over 3 years ago in reply to ipowyourface

    The readings on my Fitbit Charge 4 are pretty much spot on, and if it doesn't registers Sp02, it doesn't show a made up value like my Vivoactive 4s did.

    I wanted to buy a Forerunner 245 after all because I want the sports profiles, but such mediocre functions turn me off instantly. I had hoped the issues had been resolved by now.

  • 0 over 3 years ago

    Just turn it off. It's not working at all...

  • 0 over 3 years ago in reply to 4845238

    I did the same...

  • 0 over 3 years ago

    I work in low oxygen environments with supplemental oxygen and regularly check my SpO2 with a pulse oximeter like the one pictured.  I was hoping the FR245 could be set to alarm at low oxygen, but of course a) it's entertainment value only, not an industrial device; b) it can only be set to automatically monitor O2 level during sleep; c) there's no alarm; d) it requires you to stay so still that it seems that the slight vibration of airflow and machinery means it won't complete a reading; and e) the reading may not be any good anyway.

    That said, accurate readings from a proper pulse oximeter can be wildly variable minute to minute, If a person receiving nasal supplemental oxygen talks a lot or mouth breathes, their reading may dive to the low 80s, and then after a few seconds of careful deep breathing through the nose it will be back up into the 90s. On doctor's advice, I can pass on that temporary low blood oxygen doesn't do lasting harm, so long as it's sufficient to maintain consciousness, and from experience that a seated person may not even feel affected by blood oxygen in the 60s. Their judgement and ability to perform physical work WILL be greatly affected, however.

    Garmin does say that cleaning the sensors may help improve SpO2 readings, so if you care, maybe that's a thing.

  • 0 over 3 years ago

    Hello,
    first of all, one should not be too precise about the information from important medical parameters on a running watch. The factors that can influence everything here are diverse.
    About your photo: The correct sensor sits on the finger like in a hospital. This is where you can measure most precisely. However, the Forerunner measures on the arm, there is hair and the watch is often not tight enough. These are two mistakes that can easily be multiplied. In addition, there may be a dirty sensor ...

    Only when everything has been checked optimally should the values be approximately usable.
    At least sufficient to identify trends and serious undersupply.
    Whether 98% or 95% is not important for me with such a "measuring device".