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Heart rate - chest strap - way out sometimes

cardiffdavid
over 4 years ago

I use a tickr chest hrm.

I notice when I start a run the hrm is often up at about 170, but this I am certain is totally wrong. It is like it even if I’m doing 11 minute miles for example.

It stays like that unless I walk, then it comes right down and I can run again and get reasonable results.

However, on my second session today it was mad. Went to 185 whilst doing an easy warm up - I then did a very tough fartlek session and the hrm continually dropped as you can see in the pic and afterwards I had an average hrm of 94. Totally messed up the data for me - about 280 calories when for 5.50 miles it would more likely be 700 even for an easy paced session, and the training effect was probably effected. The hrm has a new battery and the earlier session recorded fine.

I was so annoyed I got Amazon to agree to a refund and I’ve ordered the more recent version of the hrm.

I thought afterwards though - is it the watch or firmware? 

any thoughts very welcome. I’m hoping the new hrm solves it.

thanks.

  • 0 over 4 years ago

    Basically the chest strap picks up the electrical signals of the nerves that fire the heart muscle. As such, it depends on good electrical contact between the strap and the skin.

    In cool conditions, when the skin is dry, there can be poor electrical contact, and the strap can report stray static electricity signals (especially from the technical wicking fabrics of some running tops). Typically these will report a pretty high HR. It usually goes away after 5-10 minutes as you begin sweating, and there is better electrical contact. Which is what your posted graphic shows,

    The normal way to deal with this is to pre-moisten the sensor pads on the strap (and possibly your skin) before starting your workout, until natural sweating can kick in. Some people go further and use an electrode gel.

    Regular washing of the chest strap can also help prevent the accumulation of salts in the fabric of the strap, which can provide an alternative electrical pathway for static signals.

  • 0 over 4 years ago in reply to mcalista

    Creo que todo esto es más complejo. No todo se limita a la transmisión de los impulsos nerviosos sobre el sensor. El reloj debe de interpretar los resultados de la banda de pulso. ¿Software? 

    Tengo un problema similar con una banda de pulso Gpsport. Una vez analizo el entrenamiento en Garmin Connect, compruebo que no tengo informe de gráfica de respiraciones, ni condición de rendimiento. 

    Esto no me sucede cuando llevo un sensor de brazo (fotoeléctrico), con el cual los datos son completos y correctos. 

    Desde mi ignorancia, creo que podría ser debido a circunstancias análogas a otras vinculaciones inalámbricas como auriculares u otros sensores

  • 0 over 4 years ago in reply to mcalista

    Thank you. I should start doing that - I used to.

    However the later readings are still completely wrong and can’t be accurate, but of course could still be related to the contact issue. 

  • 0 over 4 years ago

    Consistent bad readings over the course of multiple runs... in my experience that points to a failing strap.  If it is just a one off problem here and there... usually a issue with tech fabric shirt static (especially in winter or biking), and/or not wetting skin/strap enough.  Not sure on the protocol for the Wahoo strap, but with Garmin I wet the front wetting strips as well as the back side that is on skin, plus a bit extra on chest.  For races I use a heart rate electrode gel from amazon (stays wet on chest while waiting around or on bus), aloe gel also works well i hear.

    I've had a couple fail in the past, sure is tough to determine what is wrong or if it is bad... since sometimes it will work?!  lol  I have started getting the super cheap 3yr warranty through amazon, have worked out well :-)  (most recent death, last year was... oops, put strap AND sensor in the laundry! lol)

    Kinda gross, but after long runs, sometimes I notice a light area where strap was of deadskin.  So before key workouts I make a point of scrubbing the strap area with an exfoliating soap that we happen to have in shower already.  Figure it will help with signal detection.  I was in a medical study one time where they had to do that until the skin measured a certain Resistance with their meter (in that case it was down by ankle with steel wool if i remember right!!!!?! wtf! lol) 

    One other consideration is that HRM strap is actually not connected (or disabled) and its using the optical sensor, again, very tough to tell if you aren't paying attention at the start of a run.  

  • 0 over 4 years ago in reply to NickMN

    Thank you.

    ive certainly not been setting it at all (which I used to do a few years back) so will again and I’ve ordered some gel too to use for key sessions. 

  • 0 over 4 years ago
    cardiffdavid said:
    I use a tickr chest hrm.

    Could it be that the HRM is faulty?

  • 0 over 4 years ago in reply to DPSK

    I’ve sent it back and have bought the latest version which arrived earlier Thumbsup

  • 0 over 4 years ago in reply to cardiffdavid

    Hi David,

    If you get a workout in this weekend let me know how it goes. @ me and I'll check in on Monday. 

  • 0 over 4 years ago

    Looks very similar to my issue - see the fr 935 section.

  • 0 over 4 years ago in reply to AlmaataKZ

    I did a couple of runs saturday and the new hrm seemed good. It had a few crazy spikes at the start which I'm used to, which went on a little longer than I hoped, then settled down nicely over a 20k run and a short 3k one later. I also used some connective gel I got off amazon.