For the past few weeks I have been part of the pre-release testing team for the new arm worn heart rate monitor from Coros which has now been released. This is just a very quick summary of my findings from having used it for a few weeks.
For full disclosure the monitor was sent to me by Coros and in return for testing it and providing feedback I get to keep the device.
I tested the HR monitor while using a Coros Vertix 2 running the Coros beta software which allowed the watch to use it's wrist based HR monitoring, a chest strap connected via bluetooth (in my case a Polar H10, reasonably new with new batteries) and the Coros HR monitor.
The HR monitor is rechargeable using the supplied magnetic charging cable, the magnet is very strong so very little prospect of it accidentally disconnecting while charging and it charges quickly.
Once charged it connected seamlessly to my Vertix 2 using the QR code from within the Coros app, following the initial connection the monitor automatically connected to the Vertix 2 when placed on my arm. The HR monitor detects when it is worn and turns on/off automatically meaning that it was ready to go before the Polar H10 on most occasions.
The only issue I experienced with this was if I stood still for too long waiting for the Vertix 2 to pick up GPS which would cause the Coros armband HR monitor to turn off. This was simply resolved by moving it around until it turned back on. The benefit of this system is that it helps preserve the battery of the monitor which after 3 weeks or so I have not had to recharge, in fact it is still on near 50%, the battery percentage is displayed within the Coros app.
It took me a little while to get used to putting the monitor onto my arm, not because of any design issue but because I have the coordination of MR Bean and kept snagging it on my watch or pinging my arm when it slipped out of my hand but soon got over that. It has an adjustable strap and velcro fastening which is strong and secure but I didn't really use the velcro fastening as it was easier to just slide up your arm already secured and once in place it stays securely in place and is very comfortable, in fact after a few minutes I forgot I was wearing it which I cannot say for any of the chest strap HR monitors I have had.
I have used the Coros HR armband for gentle plods, steady tempo sessions, intervals and short hill sprints, in all cases alongside both the Polar H10 and also the wrist based measurements of the Vertix 2. Runs took place in all weather from torrential rain to unusually hot weather but I have not had an opportunity to test it in cold weather. On all runs the armband readings, the Vertix 2 readings and the Polar H10 were within a few beats of each other, the only time they drifted was on the hill sprints or for 30s or so after intervals when the Polar H10 was way off. I am satisfied that it was the Polar H10 which was displaying inaccurate readings as it was showing very low heart rates immediately after hard efforts indicating that it had stopped increasing at some point during the effort, both the Vertix 2 and armband monitor both matched almost exactly. Repositioning the Polar H10 resulted in its readings jumping to match the other monitors. I had no issues at all with the Coros armband during use.
From my limited use so far I have found the Coros HR monitor to be accurate, reliable and easy to use and far more comfortable to wear than any other monitors that I have worn. I have not noticed any noticeable extra battery drain on my Vertix 2 over using just the wrist based monitor and as it stands I will be using the Coros armband HR monitor as my primary choice.
So that is the quick version, I will likely update this to a fuller review following more use of the device, particularly on longer runs.
Got any questions about the Coros HR monitor, ask them in the comments and I will consider those as testing is ongoing.