Polar have recently overhauled their popular V650 GPS bike computer to include Strava Live Segments, GPS-based gradient, Advanced Power Metrics and improved Power Sensor compatibility.
As part of the update, you can now buy the V650 bundled with the Polar OH1 optical heart rate sensor which was launched towards the end of last year. Polar has kindly sent me the bundled package to review, but I am reviewing them as 2 separate devices.
I have recently covered my suggestions for heart rate monitors, which recommended the OH1, and I have reviewed the budget RunAR HRM which was OK for the price. So how does the OH1 do compared to wrist-based or the RunAR?
The OH1 is basically the same sensor you find in the Polar M430 which some people regard as one of the most accurate wrist-based options on the market. So, having the sensor moved to the upper arm or forearm should improve accuracy further.
The sensor itself is much smaller than the RunAR I have previously used, and it comes in 3 parts, the sensor, a strap you mount it in, and a USB dock you mound it in.
The device can run up to 12 hours of training time which should be enough for any endurance event apart from some niche cases.
It also has a built-in memory that can store up to 200 hours of training data. You can sync your data to Polar Flow with both the Polar Flow app and web service.
The major omission that will put some people off is the lack of Ant+ which potentially limits what devices it will work with, but in general, everything has Bluetooth nowadays.
The device will technically work on any area with blood flow, I have read reports of people using it on their forehead inside a swim cap when swimming – though this isn’t something you need to do as it has 30m water resistance.
In general, your upper arm or upper forearm are the best places, they are nice and meaty, so there is less chance of it moving around and losing connection. I opted for my upper arm as my forearms are quite hairy and I assumed less hair would be better for accuracy.
Set-up and Pairing
Once you have the Polar Flow software installed you just plug it in, and it will automatically sync, just the same as with Garmin devices. If it is the first time using it you will be given some set-up options, and from then it is all automatic. I have experienced no issues at all with syncing with my main Windows PC.
One of the clever things about this device is the ability to use it by itself. Once you power it up, if you double press the button again it will record your heart rate until you power down. My most recent test of the unit was during a 12+ mile walk where I was using my phone for GPS, I used the OH1 by itself, so I wasn’t wasting battery life unnecessarily. I have read reports of a lot of people using this during sleep and through general use throughout the day to identify heart rate patterns.
Most people will want to pair it with a device; I had 4 options at my disposal, the Garmin 520, Polar V650, Garmin 235 watch, and my phone. Everything but my Garmin 235 paired up fine. For some reason, I have struggled to pair it up with that, even though I have previously used a Bluetooth HRM on it before. I think it could be user error more than anything.
Overall, this did exactly what I wanted to with minimal errors. I wasn’t able to test it against a chest strap, but the most important thing to me was to have an HRM that didn’t randomly show 200bpm followed by 80bpm a few minutes later. These erratic results are something the Garmin Forerunner 235 is prone to doing, and in general something all wrist-based heart rate monitors will do.
My most recent walk was a perfect example of the inaccuracies you find with wrist-based devices, at one point the Garmin spiked from around 95bpm to 190bpm and back down to 95bpm in the space of 2 minutes. I think Garmin auto correct these issues in their Connect software, because that walk showed a 99bpm average in Garmin, while DC Rainmaker shows 107. The Polar shows 93 average, but that included a lunch break, and I paused the Garmin for that.
The day before had similar issues, I went for a long bike ride covering 65miles, in this test I used the OH1 with the V650 and the Garmin 520 with the RunAR. In this case, Garmin had a peak of 183bpm with an average of 126bpm while the OH1 paired with the V650 showed a peak of 163bpm with an average of 127 bpm. The RunAR suffered from some bad dropouts whereas the OH1 is much smoother. In Garmin’s defence, they do well at getting an accurate average with only 1bpm difference. The graph shows some weird results at around mile 16 as I ran over a big rock and blew my inner.
The previous weekend I went on a moderate length run for 9 miles and used the Garmin 235 with the RunAR and my phone using the Polar Beats app paired with the OH1. In this case, both devices perfo