As yesterday’s least best-kept secret was re-released on a suspecting world (Garmin 630) I was plodding around Loughborough in circles. Both mentally and physically.
I was prompted to think again of optical Heart Rate Monitor (oHRM) accuracy.
Yesterday also saw the release of the Garmin 235 (or is it 225 or 325, I get the numbers confused) with oHRM and we’d seen the innovative TomTom Runner 2 with oHRM last week. The TomTom was pretty accurate on the oHRM front.
And then I remembered as I was writing THAT TomTom post I had made a mistake (corrected before publication) with the data in using the wrong HR fields for comparison. On one test I’d actually transposed one result onto the same result, thinking it was a chest strap vs the TomTom. Funnily enough I got a near perfect match as I was comparing a chest strap with itself.
Luckily I spotted it as I say. (Wasn’t too hard!)
So what got me mentally thinking in loops yesterday was that maybe I’d made that same mistake with my accuracy review of the Scosche Rhythm a few months ago. Here’s the graph again Garmin HRM-RUN vs Scosche RHYTHM and you can see why it’s been nagging in the back on my mind. It’s like comparing two chest straps against each other – or one chest strap against itself:
So I got my new Garmin HRM-TRI (ANT+ only) and established a heart rate with the Garmin watch. Fine. I put on the Polar M400 (Bluetooth only) and waited for a signal as I fired up the Scosche (ANT+ and BTLE/BLE/Bluetooth SMART v4. Bang there we go Bluetooth Heart Rate. Simultaneously pressed go on both devices and off I went plodding around a training Half Marathon.
This is what I got.
Why is it so bloomin accurate?
I remember delaying having a look at one after seeing the dcrainmaker review; I just couldn’t believe it. But nope. It’s true. dcrainmaker was right in his pronouncement of the most accurate oHRM there appears to be.
TomTom’s is good. But not as good (below)