Random HRM readings

Just been given a Timex Ironman HRM (ladies version - ie small watch). Previously had a Ciclosport HRM, which I gave up on because it kept giving me random HR readings.

The Timex one is better, but still not great. Am I wearing it wrong or is it faulty?

Yesterday on my half marathon, it seemed to be showing the correct heart rate about 75% of the time. The rest of the time it was either way too low, or way too high (eg 70 or 280!)

I wasn't running close enough to anyone else for it to pick up their HR reading, if they were wearing a monitor.

So, is it me?
Is the product likely to be faulty?
I wet the sensors before putting it on, but, ladies, where exactly do you wear the strap? Do you jam it right up under your boobs (sorry, lads!) or do you wear it a bit lower?

Any advice before I send it back?



  • Sometimes thsy just lose the signal - so you occassionally get random readings. Unless you feel unwell at the time, don't worry about it.

    And jam it right under your boobs.....

  • I can understand that they sometimes give weird readings, but is it normal for them to give them 25% of the time? Given that I was only looking at my watch every 3 or 4 minutes and it was right 3 times out of 4, presumably there could be a lot of weird readings when I'm not looking.

    I suppose I should turn on the alarm so that it beeps when it's out of zone and that would tell me when it's wrong.

    But it seems a bit much to me...
  • Mmmm yes, it shouldn't happen that often. Try contacting Timex, see what they say.
  • If I wear my HRM I jam it right under the bottom seam of my enell bra. If the belt is not held tightly in the correct position it will give faulty readings.

    I also believe certain other electrical equipment can interfer with the signal.
  • Very little should interfere with the Timex. Three major problem can occur - the strap not being in the right place, the strap electrodes not being in good enough contact with with skin and the battery dying.

    It should only be the second you need to worry about as you seem to have it positioned about right. make sure the strap is faily tight and is wet with saliva before you put it on. You may need to tighten the strap slightly more than you currently have it, as if it moves around at all this can really change the pickup of the electrical impulses from the body.
  • MuttleyMuttley ✭✭✭
    I've been plagued by this as well. Analogue, digital, no-name or brand-name, whatever. I've just ditched an hrm in a fit of rage because the bloody thing kept spiking or jamming on literally every run. That was the cheapie dhb one from Wiggle btw - avoid, if only because you can't reset the heart rate without resetting the stopwatch as well (!).

    I've been using hrms long enough to have an idea of how to help them work properly, as explained by David above.

    I have another one on order, one that's been recommended as good by many. I'll see how it performs, but in the meantime I have questions about the reliability of the technology.
  • Well, it sounds as if I'm not the only one!

    I actually called Timex up and they were really helpful. Basically told me to make sure that I didn't switch it on near anyone else wearing a transmitter (I was right next to my husband, who was wearing his Polar HRM when I switched mine on on Sunday, so it could have been that). And that I wasn't near any other transmitting source (eg PC etc).

    Also said to make sure it was on tight - which it was. There's a fine line between tight enough to pick up the reading and so tight it removes the skin on the underside of your boobs, though :)

    They then said there are some people (about 1 in 10,000) who just don't seem to be able to get a correct reading and need to put their chest strap on their backs or on their sides?!

    Alternatively, it could just be bu55gered (loose connection to sensors in strap), but I'll try it again tonight switching it on while no other HRM in the vicinity and see what happens.
  • I use the same Timex HRM and have also had the problem with random readings. This is actually my second strap- the first had to go back as after giving increasingly random readings it actually snapped - apparently due to a manufacturing fault at a plant in China

    I have a lot of trouble getting the strap tight enough. I have it on the smallest setting and then I also need safety pins to hold it in place. I've tried wedging under my bra (sports jock) but this makes it difficult to breathe. Any other ideas for keeping the monitor in place? Maybe manufacturers should be making a smaller chest strap for ladies, which would be more likely to stay where it should?

    I've also had problems when I've switched my HRM on away from other HRM users so not sure about that explanation. But I'm going to try putting the monitor on my back or side (if it'll stay up!) to see if this helps.
  • NessieNessie ✭✭✭
    Not much use to those with Timex's, but Polar's new(ish) Wearlink strap has the contact woven into fabric strips on the belt, rather than on the plastic transmitter unit. Not only do you get perfect contact, it is much comfier AND you wet it with water - no need to gag every time you go to dampen it........
  • Slow Scarlett

    That doesn't sound very encouraging. :(

    The guy from Timex told me that, apparently, only a quarter of one percent of all their products are actually faulty...

    I do think maybe my problem is that I can get it to sit right, although it doesn't feel loose. I also wear a sports jock bra, and I do shove the strap as far under my boobs as possible, so it's actually above the band on the bra. Not sure whether that's right, though. I'll try my super compressing bra tonight. There'll be NO movement from that one!

    If I'm still getting dodgy readings, it's going back and I'll see about that Polar one that Nessie mentions.
  • NessieNessie ✭✭✭
    You could try the conductive gel stuff rather than just water or saliva. Boots should sell it - those electronic muscle pulse stimulator machines (get fab abs without going to the gym!) use it - presumably because you will never sweat while using them.

    Maybe you aren't conductive enough.....
  • Hi guys

    I've got Polar M32 (i think) and having similar problems. Keeps insisting my HR is in double figures (rather than triple) when im running. Eg. first long run yesterday after lay off. For a mile was OK-telling my HR was higher than would be normally, as I expected coz unfit. Then readings dropped to 131 and dropped further to 91 etc.Can take me a while to get a reading on it too. Had it less than a year and it worked fine for quite a while. Any ideas? Cheers.
  • Beanington - you say your HRM is above the bra band....is the HRM then flat against your ribs? Or against your boobs?

    I wear Sports Jock bras and (for me) the HRM goes directly under the band....any higher and it would be trying to measure boob-density not HR! Guess it depends on exact size and shape....!

    You might also want to place the HRM slightly off centre (I have to put the centre of the transmitter slightly to the left) - no idea why but this gives me a more stable reading.
  • Cakes - dunno. Maybe try the advice given to me above, making sure contact with skin ok and strap seated correctly etc. Otherwise, if you haven't used it for a while, it couldn't be battery probs could it?

    Nessie - the run I did yesterday was in the HEAVING rain, so I think there was plenty of conductivity due to sodden kit and sodden me. However, I will probably try that gel stuff, although the Timex guy didn't seem to think it would make much difference.

    At least with all this worrying about HRM reading, it gives me something else to think about when I'm running. Ran a PB in my half marathon yesterday even though technically I should have been dead on a number of occasions due to HR in excess of 280!
  • KY Jelly is good for helping get a good contact. Apply it liberally to the electrodes. It works out cheaper than the proper conducting gel if you buy own brand rather than KY itself.

    Just don't get embarrassed asking for it ;o)
  • Back again to report on progress....

    I've now been for two runs with my HRM positioned slightly to the left, sensors liberally covered in KY Jelly (Boots own brand version- they don't sell the conductive gel at my nearest branch- I don't embarrass easily) and with the strap under the band of my sportsjock bra - and its worked! The HRM seems to be giving the sort of readings I'd expect- no sudden 39 or 240.

    Thanks to everyone for all the advice!!!

    Beanington- how are you getting on?

  • Slow Scarlett - haven't tried the gel (KY or other) yet, but it's been much better since I've stopped switching it on whilst standing next to my husband wearing his Polar HRM. Still the odd 120 or 170 while running at a steady pace (when I would be expecting something in the 150s) but it's liveable with now.

    I'll try some gel as well - when I can get to a Boots sometime.

    I've just gone and injured my ankle now which means marathon training schedule out the window :(((

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