Review on 🏃 XOSS Optical Armband Heart Rate Monitor: Bluetooth 4.0 & ANT+ Wireless Health Accessories for Fitness Tracking by Cristina Gonzalez

Edit after a few runs: This device suffers from intermittent "cadence lock" which means the heart rate readings are locked to your cadence and not heart rate. This has happened to me sporadically on my last two runs now, once on the treadmill and once outside. My running heart rate is usually an average of 130 bpm, but now it shows intermittently 180 bpm, which is not possible (my max heart rate is around 170) and matches my running cadence. This has been an issue with optical HRMs in the past, but most brands have fixed this issue with software updates. I still give it 3 stars because it doesn't have this problem when used for cycling. Original review below: I've only had it for two days, but so far it has exceeded my expectations. I decided to take a chance since it's half the price of the 'famous brands' options from Polar, Wahoo, and Scosche. Note that this XOSS device looks identical to the more expensive "Coospo" device sold here at Revain. To test the device, I first rode it on a regular outdoor track and the readings are almost identical to my chest strap. It's also quite responsive to tempo and level changes. Overall I'm very happy with the accuracy, especially when compared to wrist monitors which have never worked for me. Please note that I wear this device on my shoulder and the sensor is about halfway between the top of my bicep and the outside of my arm. To test the battery life, I wore the device continuously for 24 hours and I have to say that it still worked after a full day of work! So the initial battery life is even better than the advertised 20 hours. The only obvious downside to this watch right now is the strap, which feels very fragile and is likely to stretch and loosen with use. I will update the review after further use and testing over the next few weeks.