I'd been using the Polar H10 chest HRM since August 2022. It worked fine for the most part, other than a few instances of the battery compartment being wonky and giving inconsistent readings until I fiddled with the flexible contact inside. Well, it finally annoyed me for good recently when it started to freeze on a BPM for several seconds before dropping/rising immediately. It would do this every few seconds and my BPM readings were always wildly off. I tried everything I could think of to remedy this and figured, after reading tons of similar stories online, it was best to just move on finally and buy something new. I grabbed the COOSPO HW9 Optical HRM and have been using this with zero issues so far. Since it uses optical sensors (like a smart watch), there's no need to wet it first or apply electrode gel. You simply place it around your forearm or your upper arm (bicep). It has its own app but I prefer using the Polar Beat app so I can see the nice colorized graph in real time. That's what's cool about the COOSPO HW9, it connects to pretty much any HRM app (including PULSOID if you want to show your HR while streaming online). All I had to do was turn it on, go into Polar Beat, remove the Polar H10 from my paired devices list, and the COOSPO HW9 immediately showed up and I was able to pair it right away. In order to test the accuracy of it, I have used it in conjunction with the continuous HRM feature of my Galaxy Watch 4 as well as testing it by comparing my heart rate with my Galaxy S10+'s HR measuring feature and the COOSPO has been spot-on for me. A cool feature this thing has is that it has an indicator light on it that changes color based on which BPM range you're currently in. It's especially helpful once your heart reaches 180bpm because the light turns red and the armband vibrates a couple times. That's been helpful when I play because it reminds me to focus on breathing and calming down during whatever song I'm playing that has my heart rate getting so high. If you use the Heartool app, you can change the HR alert value to something other than 180bpm. Anyway, just wanted to give this thing a shoutout for anyone looking for their first HRM, a replacement, or an alternative to a chest HRM. This one is pretty comfy to wear, far better than the Polar H10 to me (which would bunch up on my sides and back). I also like that it has an internal battery that you charge with a magnetic charger (it's recommended to charge it by connecting it to a laptop/computer or DC 5V power adapter).

Update 8/14/24: The monitor recently developed a problem of suddenly sending readings much higher than my actual heart rate. I contacted the Coospo people about it. They responded quickly and sent me a new one. So, excellent warranty service from Coospo. Also, while I am here, I want to recommend the Heartool app for use with this monitor. If you need to see your HR in big numbers on your phone while you exercise (while using an armbike, for example, where looking at your watch is impractical) then this app will do the trick. My Matrix treadmill has metal inserts on the handles for heart rate but, of course, they don't work very well. They never do, on anything. But it also has Bluetooth that will link with HR monitors like this one. Works great. I wear this monitor on my forearm; the treadmill picks it right up and displays my HR on the treadmill screen. As best I can tell, the HR it provides is quite accurate. This monitor also greatly improves the HR detection on my Apple Watch. To do this, you start up the monitor, go to Settings>Bluetooth on your watch, find the link to the monitor in the list and click it. From then on, if you are using this monitor while wearing your watch, your watch will use the arm monitor output rather than its own. My wife, after seeing me use mine, bought one for herself to use with her Apple Watch for her outdoor runs. She really likes it. Her watch's HR reading had often paused while she was running but this monitor never does that.

As a fitness enthusiast, finding a reliable and accurate heart rate monitor is crucial to tracking progress and optimizing workouts. The COOSPO HW9 Bluetooth 5.0 ANT+ Heart Rate Monitor is a great investment I've made for my fitness journey. The Bluetooth 5.0 technology ensures a seamless and fast connection to my devices (especially during my DDP Yoga). The compatibility with popular fitness platforms adds a layer of versatility that caters to various workout preferences. The Optical HRM Sensor is a game-changer, providing precise heart rate data for cycling, running, and fitness training. What sets the COOSPO HW9 apart is its ability to break down heart rate zones and calories burned, offering valuable insights into the intensity and efficiency of my workouts. This feature has undoubtedly taken my training sessions to the next level. The armband design is comfortable and secure, allowing me to focus on my activities without worrying about the monitor slipping or causing discomfort. The device is also sweat-resistant, making it perfect for intense workouts. What I love most about the COOSPO HW9 is its reliability and accuracy. I can trust the data it provides, giving me the confidence to push my limits and achieve my fitness goals. The long battery life ensures that it's ready for action whenever I am. If you're serious about maximizing your workouts and achieving peak performance, the COOSPO HW9 is a must-have.

So, I've used it twice...once on the trail and once at the gym. So far...nice! It has the magnetic charger which is convenient and lites up when fully charged. The unit has a power button...a very positive feedback experience, compared to passive power ups like chest straps. I wore it on my upper forearm and it was able to track HR without issue. I paired it with polar beats and it tracked HR from start to end. Battery status shows in the app. At the gym,it had no problems even with arm movement. I Nordic walk a hiking trail and again, no comms issues. Once the device was in beats, it picked it right up. It comes with a second strap, so I can swap them out to clean them. It's small and I forget it's there after I'm into the workout. I especially dont miss having to set the strap like a chest strap. If it holds up, I'll keep coming back. Regardless, I'm sold on forearm strap formats over chest straps!

I bike and walk everyday. As I get older and wiser I needed to make sure I was properly zone training so that I don’t get injured. This HR monitor is simple and is accurate, I compared it to my Apple Watch and to a chest monitor and it is the same. Bluetooth works with my Apple Watch so I don’t need to pair to my phone, but you can pair it to your phone. I also pair this to my computer for Zwift and works amazing. I have had it for a month and it’s still holding its charge. I like the way it looks and it’s easier to put on with all my gear on, I don’t have to remove clothes to put on the monitor unlike my chest monitor which used watch batteries. The rechargeable battery is a huge advantage so that I don’t have to swap batteries ever.

This is exactly what I have been looking for - comfortable, accurate, and budget friendly. I have tried smart watches with heart rate monitors and found them to be inaccurate and uncomfortable. I can improve the accuracy by tightening them, but that really increases the discomfort. I have tried chest band heart right monitors that were extremely accurate, but I never enjoyed wearing them and couldn't wait to take them off. I forget that I am wearing this one on my upper arm. Easy to charge, easy to pair with my phone, works with my workout apps, matches what I measure my heart rate to be with a clock and a finger on a neck artery. Exactly what I was looking for. Highly recommended.

I use this for riding my bike. I do not like the ones around the waist. I have some earphones that track my heart rate, but they will not connect to my computer. For my indoor training I use a wahoo trainer and Rouvy. This connected with out any problems. I like that it can fit around my arm. I came with two straps of the same size M. I would like to have had two one large and one medium. The medium, at its largest size, just fits my arm. I am a normal-sized man for arms, I would say. I am very happy about the device. I would like it to have some extra features like blood oxygen level and blood pressure for the cost, but in its category, I feel it is a solid device and good equipment.

I have neglected to charge this thing since I bought it a month ago. It is still running strong from the initial charge. I do not connect it to a phone or smartwatch so I don't actually know how much of a charge it has left, but I do connect it to the treadmill at my gym for 20 min or so. I've used it for 2 mile runs and a while in the gym, total about 30-60 minutes, 5-7 times a week. After this I will charge it fully in hopes that I do not create some bad battery memory, not sure if it applies to this type of battery.

As an Ironman triathlete, mountain bike racer, and distance runner I've owned just about every chest and wrist heart rate monitor made. By far, this device is the simplest to use, super comfortable, and 100% reliable. I sync'd this HRM with all of my devices with no issues (Peloton, Wahoo! cycling computer). Especially w/ Peloton this is a huge difference, even the Peloton branded HRM has issues staying connected and especially reconnecting each workout. I'll never wear another chest strap HRM again.

I was looking for a heart rate monitor that could be used with simple applications or just to be aware of my heart rate, without having to use specific applications or track every aspect of my life. This heart rate monitor has worked wonderfully with a basic application and, obviously based on other reviews, it works just as well with more robust applications if that is what you're looking for. Coospo has been responsive when I've had questions and I would definitely recommend this product.