COROS Heart Rate Monitor, Comfort, Easy to wear, Auto-wear Detection, Advanced Sensor, Precise Data, Bluetooth, 38 Hours Battery Life, Connects up to 3 Devices at Once, for Run and Bike

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.

OMG. I didn't even know I needed this until I was told about it and tried it out! While I've used chest straps for years, I have put up with the chafing, itchiness, and general uncomfortableness of them (multiple brands). NO MORE! After using the Coros HR Monitor Arm Strap I will NEVER go back to chest straps again! When worn on the bicep it is hardly noticeable. Barely even know its there when worn! It linked up fast and easily to my Coros watch! Discovered I can even link it to my Strava account thru phone's bluetooth for heart rate monitoring! I use Android, but it paired to my daughter's iphone also when she asked to use it!Linked up to my bluetooth exercise bike at the gym too! When used for my runs and gym, the readings adjust instantaneously to my heart rate changes with no delay and more importantly accurately! This will be a game changer come this winter since the monitor will be closer to my heart and respond more quickly in the cold temps! Stated battery life is 38 hours, so perfect for thos LONG ultras! Gonna wear for my 50k in three weeks! One of the best things is it turns on and off automatically when worn or not, no more power buttons YAY! The strap is easily removed to wash and the unit itself is waterproof, so no issues with rain! As it is brand new item, there haven't been many updates yet, but Coros always improves and updates as needed from my experience. This has been probably the best $79 I've spent during my running years. Gonna suggest to all my friends to get one!

So much more comfortable than other HR monitors -- love it. Now if they would just make a good app (ugh)... Seems pretty accurate, know that chest straps are supposed to be better, but never liked the feel of them. Don't mind wearing this at all. A bit of a drawback is that the range across which the strap cinches down doesn't vary much, and I'd like it to go a little tighter. Been using for 6 months and still works well. Pair it with the Polar and Strava apps. Battery life is very good as well. Great HR monitor.

Bottom line up front: buy this heart rate monitor, you won't regret it.I've spent the last few months putting this COROS armband through its paces. As a triathlete with a CrossFit problem, here's what keeps me coming back:1. Accuracy. First and foremost, it consistently delivers results on par with my Polar H10 (which now sits in a drawer as a result) and, in some cases, was more accurate (especially activities that sometimes involve weird chest movements or jumping, like in CrossFit). It showcases an absolutely snappy response to abrupt changes in HR during interval training. And, because it's an optical HRM, zero issues with tracking correctly from the moment you hit start, no matter the environmental conditions (unlike the age-old problem with humidity on chest sensors).2. Comfort. It's so light you completely forget it's there! Importantly, it never rubs, chafes, or creates discomfort. On the upper bicep, it's never in the way, no matter the activity. The band itself easily adjusts to any arm and it can slide right off the sensor to throw in the washing machine and clean (when was the last time you washed your chest sensor??).3. Ease of use. Frankly, it just works. If you own a COROS watch, this will sync right up. Though, while it works seamlessly with the COROS ecosystem, it will work with any Bluetooth-connected device (I have paired it with indoor rowers, other exercise machines, and non-COROS watches without problem). Lastly, this thing has a long battery life and is rechargeable, so you never have to worry about not having a spare battery on hand (the app or watch will even tell you how much battery is left).Zero regrets on this purchase. I strongly recommend the COROS armband to anyone who asks.

You wear this heart rate monitor and completely forget about it no matter the activity. I find it very accurate and convenient.