Wednesday, September 7, 2011

Heart Rate Monitor blues

If you have been following my blog then you'll know that I was having a lot of problems with the so-called soft Heart Rate Monitor strap that comes as standard with the Garmin 310XT. Once I swapped it for the "classic" HRM that came with my now defunct Forerunner 305, the problems seemed to go away. It started playing up again last week so I decided to replace the batteries (although, to be honest, they shouldn't have worn out already). I couldn't find any shops stocking the little CR2023 battery that it was running on. It was only when one of the attendants gave me the sort of look that I expect she would have reserved for somebody looking for a Sega Megadrive that I thought I should do some further research on the internet. Well, I found out a couple of interesting things. First off, according to Garmin, you should wait for one minute after taking out the old battery and before putting in the new one, to give the HRM time to reset (in particularly its battery level). The other thing I learned is that the 2023 in the name of the battery actually means something: the 20 refers to a diameter of 2 centimeters while the 23 means that the thickness is 2.3 millimeters. In fact, there is no difference other than thickness (and corresponding battery life) between the CR2023, the CR2025 and the CR2032. What is more is that Garmin actually recommend the ubiquitous CR2032 as a replacement battery!

In the meantime I have been running quite a bit faster than I usually do. I suspect that it is because my heart rate was also correspondingly higher although I'm secretly hoping that having lost a few kilos since the Ironman is helping me run faster... We will see on the 18th, when I have a Half Marathon in Valladolid. I'm still recovering from the cold that knocked me out last week so I doubt that a PR is on the cards but I'm hoping to have a good solid race in preparation for the Marathon.


  1. Hey Rob, don't count yourself out on that PR for the Half Marathon. Sometimes having a random cold that sits our butts back on the couch for a few days is the best thing that can happen.
    Good Luck!

  2. Thanks for the encouragement Bertie. You are right that sometimes a forced break is just what we need - after all, the body usually knows best. On the other hand, if I'm totally honest, I want to have an excuse if I don't get a PR, so that I can still pins my hopes on the sub 3 hour Marathon. In any case, there's still time...

  3. Yep I have encountered the same twist of technical logic with garmin and batteries. But actually found out before I got to change mine ;-). I have an 305 edge for the bike. Are you sure your 305 is dead?

  4. Hello Warrior

    Well, actually I was referring to the Forerunner 305. And yes, it is dead, at least the battery is. That is to say it won't charge. Sure, I could probably get it fixed but it was a good excuse to upgrade to the 310XT.

    For what it's worth, I've ended up buying a new "classic" HRM strap for the Garmin. The old one seems to have detoriorated - it is over 3 yuears old, after all. HOPEFULLY, this will put an end to this nonsense. In the meantime I'm relying on my cheapo Suunto backup watch...

  5. PS: early indications are that my brand new classic HRM is working perfectly...