I was a part of a voluntary COROS HRM device testing program for two months ahead of the public release for this device, and was so impressed with the metrics it provided that I felt it valuable enough to buy as a gift for a fellow athlete. This quick review reflects my experience with the device during testing (and afterwards), and is not sponsored by COROS.

About me: I’ve been an avid runner since 2012, trending towards longer endurance-based events. I’ve run a number of ultramarathons and a handful of 100 mile races. I also do a bit of road and indoor (stationary trainer) cycling as cross-training.

Things I like: This HRM appeals to me because of its simplicity and versatility. I like that there are no buttons (it senses when it is being worn), and I like the fact that once you set the sizing, it stays put and is easy to slip on before an activity. For sizing: I’m 5’-9”, 160-ish, and I still have plenty of slack in the strap…but I don’t do a lot of lifting. It is SO much simpler and WAY less noticeable than a chest strap. I also love the magnetic charger–even though it is relatively short (and proprietary). Charging is quick, and the battery life is ample, so it won’t be charging for very long anyhow.

Data accuracy: During testing I compared this new HRM to my Wahoo TICKR HRM, as well as data from wrist-based optical HR sensors (COROS Pace 3 and Apex 2 Pro watches). The short summary is that the most consistent data came from this COROS armband. The KICKR chest strap–while plenty accurate–was slower getting an initial reading before beginning an activity, and had some data drop-outs during the activity as well. Chest straps occasionally require adjusting during activities as they loosen and slip. Wrist-based HRM sensors work fairly well, but are somewhat activity dependent. Cycling (especially if venturing off-road) can jostle these sensors from wrist contact and can result in some inconsistent data too. The armband stays securely in place, and is so comfortable and light I often don't notice I'm wearing it. During testing there were data anomalies from all devices, but the armband HRM produced FAR FEWER than any of the others.

Material thoughts: The armband material has held up well so far, but DOES tend to get stinky and discolored with wear. I’ve had mine since early July, and wash it with soap and water occasionally when I can’t stand the funk, and it cleans up nicely (see photos). Replacement armbands are also available, though I can't see needing one for a good while.

Something I wrote to the product testing group during evaluation: “The more I run with both an arm and chest strap the more I LOVE the arm band. I’ve now got a rash from the chest strap and it drops signal more than any of the three HR options. I’ll admit that I’m a sucker for simplicity, so would normally just use readout from the watch (decent)…but if I need an accurate and responsive HR readout, I’m picking the HR31.”

Summary: This armband doesn’t miss a beat (ha!) and makes a lot of sense for an athlete interested in reliable HRM data across multiple sports. I initially wasn’t too keen on adding another device to my quiver, but this HRM earned its place, and would be a worthy asset to those who value consistent accurate data across disciplines.

I bought this to replace a Polar H10 chest strap that was starting to fail after a few years.
I use it for cycling and have only used it twice so far but it has been flawless with no spikes or dropouts. It seems accurate and agrees with my Apple Watch which I know agrees with my chest strap. It is more comfortable to wear than the chest strap and also don’t have to keep replacing the CR2032 batteries. I was a little skeptical because I had a few arm bands in the past that were terrible but this one is solid. I bought this instead of the polar Verity because it was less expensive and I did not need all the bells and whistles. It works perfectly with my Garmin Edge cycling computer.

This is a nice heart rate monitor. I use it while riding a stationary bike. It is simple to use, comfortable, accurate, and reliable. The tricky part was finding a decent app to interface with it. The COROS app isn't all that useful during workouts. It will show your current heart rate and that's about it. In my opinion, the popular exercise apps like Strava and others ask for too much personal information upfront and are cluttered with too many functions that I don't need. Plus they tend to prod the user to sign up for a monthly subscription to "unlock premium features."

The best app I've found is ZonePoints (Android). It works well with this COROS HRM and it shows a real-time graph of heart rate, color-coded for 5 different zones. It also saves each workout to history and stats for comparison.

Just opened the box. Apparently the device doesn't come with everything you need to charge it. It does come with a specialized charging chord that magnetically connects to the device. So using this chord is mandatory. However, the chord is only 10 inches long, which is not long enough if you plan to plug into a wall receptacle. And on the other end of the chord is a male USB C connection. That means, I need to add or purchase my own female USB C block so I can plug the chord into a standard wall electrical receptacle. I guess CORUS just assumed I'd have a free one just laying around. But I don't. How much would it have cost them to make the charging chord a little longer or at least include a charging block? I will update my review after I purchase a method of being able to charge the heart monitor and can test it further. But for now, it's one star.

I’ve tried a few heart rate monitors over the years, and this one from COROS is easily my favorite. The biggest win for me is comfort — being able to wear it on either my forearm or upper arm makes a huge difference. No more dealing with a tight, restrictive chest strap that gets uncomfortable, especially on longer workouts or rides.

Accuracy has been spot on, and it connects quickly without any issues. I’ve used it for both cycling and gym sessions, and it’s been super consistent the whole time. It also stays in place really well, even when I’m sweating a lot or moving around.

If you’ve ever been annoyed with chest straps, this is a no-brainer upgrade. Way more comfortable, just as reliable, and honestly something I don’t even notice I’m wearing anymore. Highly recommend.

Fantastic, works great, comfortable, only issue I have is that the buckle/metal fastener on it tends to rub my lats and arm, might be because I’m a more muscular build but just a small issue, no big deal. Typically if it starts to rub/get uncomfortable I switch it to my forearm and it works perfectly. I love that I can sync it to Apple health and use with my Apple Watch as well as my Coros watch. Battery life is great and haven’t had an issue with band smelling as long as I rinse it. Great HR device, is very accurate and much more comfortable than a chest strap.