– Frontier X2 Smart Heart Rate Monitor Chest Strap, Wearable Heart Rate Monitor with Strain, Breathing Rate, Real Time Vibration Alerts and 20+ Fitness Activities with Continuous Heart Monitoring

Great device, functional, accurate, comfortable..

Frontier X2 Smart Heart Rate Monitor Love it. Fantastic bit of kit. Easy to use and set up. Connected to my phone easily. Connected to my Garmin watch and my Polar watch easily. Only slightly larger than a normal heart-rate monitor. Records heart rate and ECG. I can review the traces afterwards and compare with how I felt. I can press the button on the monitor to mark an event if I feel it. Gives a live read out of heart strain on my phone. I'm not sure what heart strain it, but seems useful.

Having had version 1 for a number of years, thought id try the latest version at the amazon prime deal. Apart from it uploading quicker and giving a kcals reading and more connectivity, I found there were spurious readings on the ecg trace which caused me to question its reliability and whether it was worth spending another £300 upgrading from V1. Decision was to return and now awaiting refund from Amazon despite them receiving it back 2 days ago.

Bought as a gift for my daughter to help monitor her heart rate during workout sessions. It has a strap which fits around her chest and it makes a noise if her heart rate exceeds the rate she sets, based on her cardiologist's advice. She is happy with it.

I purchased this because of a one-off episode of pericarditis at the start of this year, and i ended up in the A&E. I am a 58-year-old who is very fit and has been engaging in weightlifting and cardio exercises for many years, since my early 20s. Right after the pericarditis episode, my heart returned to completely normal, and I returned to intense exercises after 3 months. I purchased a six-lead ECG device that costs a fraction of the cost of the X2. I spent many hours learning to read ECGs and can read 6- or 12-lead cardiograms. Initially, I thought the X2 was a good idea just for the peace of mind when I do two HIIT (high intensity interval training) twice a week when I push my heart to zone 5. However, I am disappointed with the following: 1. The phone app has a minimal interface and does not show all the detailed metrics after the workout. To view the details, I need to access my online account. 2. The LED screen is gimmicky, useless and bulky. They can remove the LED screen to achieve a slimmer profile and also extend battery life. I would not like to wear it when sleeping, especially since I am a side sleeper. It would be very uncomfortable to wear it in bed. The heart rate variability (HRV) should be measured immediately after waking up in the morning. 3. They try to save on the cost without wireless charging. Most smartwatches now feature this capability. The micro USB port is a design weakness. They claim that it is waterproof. However, they make the USB port waterproof by having a rubber cap. In my case, the USB-C port was missing from the box, and I was forced to return it and ask for a full refund. 4. The subscription feature is overpriced. Really, anyone with pre-existing heart conditions should seek medical advice instead of relying on the monthly paid subscription. 5. If I have atrial fibrillation or heart disease, I would definitely keep the unit. If you have a healthy heart and you do not know how to read an ECG. It is an overkill and a waste of money. The X2 is overpriced in my opinion. In my case, I have an excellent and low-cost 6-lead ECG monitor recommended by the British Heart Foundation website. It is sufficient for me. A one-lead ECG is not as good as a 6-lead ECG unless you have episodes of AFIB during endurance sports or exercises.

Update: After working many months with their tech support, who tried hard to get the device working and even shipped a replacement. both Frontier X2s I tested were exactly the same, they work if I stay still but gave large and small periods of anomalies if used during exercise rendering them untrustworthy and useless for monitoring. So if exercise is your use case then avoid this device it simply does not work for that role and having tried multiple devices I have to conclude it is the design of the device not a single faulty one. First review: Only suitable for use while sedentary. If used while running it gives periods of noise meaning any anomalies when it appears to be working cannot be trusted as it could just be a short example of noise. I worked with support to try and get it to work reliably but it never has. I even purchased a smaller strap directly, which they dispatched without paying the postage so it was held up while I paid the postage and admin. It is a shame but as a fairly premium device for me and a couple of fellow runners it failed to perform the role that it was purchased for, monitoring during runs.

This heart monitor is easy to wear and has a great number of useful features. I really like the livestream ECG feature and the ability to be able to send information to a health professional. Customer services were really good in responding promptly to my queries about how to use the device. I also had an issue regarding the Apple Watch app, but this was helpfully resolved - it was apparent to me that the company really strives to achieve excellent customer service.

Good as fitness app and for ecg monitoring, long battery life. Pricey but worth it.

If you're returning to fitness after a health concern, this is the device to get. Real-time heart monitoring with adjustable limits, vibration warnings, and continuous ECG capture during workouts—it checks all the boxes for safe training. The weekly training load tracker is a nice bonus that keeps me motivated to hit my goals. Feeling stronger and more confident every week.

Fonctionne comme promis, mais fonctionnalités disponibles sans abonnement particulièrement réduite

I bought this device to monitor my cardiac stress level while exercising. To my knowledge, it is the only device on the market that essentially functions like a real-time cardiac exercise stress test. While it does not make that claim for obvious FDA reasons, it performs many of the same functions, albeit using the word "heart strain" as opposed to "cardiac ischemia detection using ST-segment changes", which is fair. Basically, ST-segment changes greater than a certain amount can indicate cardiac ischemia from coronary artery disease and risk of sudden cardiac death while exercising. Jim Fixx, the exercise guru who wrote the 1977 best-selling book The Complete Book of Running died of a heart attack while running at age 52. The purpose of a $700 cardiac exercise stress test is to detect this in a highly monitored setting with a nurse, etc. For daily exercise, I think a device like this one is quite useful. While not as accurate as a 12-lead cardiac exercise stress test, it does capture real-time EKG data, monitor real-time ST-segment changes, and you can configure it to vibrate if ST-segment changes reach a certain level, and then dial back your exercise accordingly to stay in a safe range. Some degree of cardiac stress is inevitable with exercise. The device has worked great--easy to use, comfortable, and it gives me tremendous peace of mind when I am exercising. It is not a guarantee and it is not fool-proof, of course, but it is better than nothing. I'm really glad I bought it and am thinking of buying it as a gift for some friends.

The ECG function is next-level—accurate, detailed, and reliable. I use it daily for both workouts and general health checks. The ability to see my real-time heart rhythm makes me much more aware of how my body reacts to different intensities. It’s helped me train more efficiently and even catch irregular patterns early. This feels less like a gadget and more like a performance partner

Initially, I had some issue authenticating for a day due to technical issues, so the device was essentially a paperweight during setup. That experience was frustrating and highlighted real gaps in their authentication flow and error handling. However, after providing detailed and constructive feedback, I was genuinely surprised by how quickly and thoughtfully the Fourth Frontier team responded. They acknowledged the issue, explained the root cause, and outlined concrete mitigation steps and roadmap improvements. Not many companies take technical feedback this seriously or move this fast, and that responsiveness was refreshing and earned my reconsideration. Now that everything is resolved, I use the Frontier X2 daily. From a technology standpoint, this device is in a completely different category than standard wearables. The level of insight it provides into cardiac performance during high intensity workouts is something I have not seen elsewhere. The ability to capture and export raw ECG data is especially valuable, as it allows me to perform my own deep analysis using custom tools and applications. For anyone serious about performance, physiology, or personal research, that capability alone is priceless. This is a powerful device built for serious users. While the initial onboarding experience needs continued improvement, the underlying technology is excellent, and the team’s willingness to listen and improve gives me confidence in the product’s future.