- 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

Works as designed. No major major design flaws. Little bit pricey I would say, but it is highly accurate startup company so they're not fully well known in the business. There's not that many people that wear chest straps to be honest. Accuracy of it is good. I bought it thinking I would exercise a lot more but that didn't happen but I used it for a good 3 weeks or so and then I just got lazy easy to set up. Works with a smartphone there was one weird issue with the battery meter on it but doesn't really matter. It'll say it's more charged than it actually probably is. That's the only issue. Other than that all around it's good

I purchased the Frontier X2 two weeks ago and have been putting it through its paces across all my activities. I love the chest strap so much that I even bought another one for a nurse friend who suffers from PVCs. This device is worth every penny. My only complaint is that I didn’t know this product existed years ago—but I’m glad I finally found it. I suffer from PACs, so being able to track my workouts on my Peloton, outdoor walks and runs, and especially record ECG activity while sleeping has been incredibly valuable. I wear it almost all the time. I honestly can’t believe the company doesn’t double down more on marketing. As a marketing professional, I see huge potential for this to become a household brand. While the price may be out of reach for some, increased volume could eventually allow for a more accessible price point for the masses. I’m also very impressed with both the app and the web dashboard. I was able to share my data with my cardiologist yesterday, and he was genuinely impressed—so much so that he took down the company information. I spoke very highly of the device, and I hope he’ll recommend it to some of his patients. Prior to this, I was using the Kardia 6L, but I strongly prefer this device.

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.

I'm updating my review for this product. I have had some interaction with customer service and used the device. First: I was extremely unhappy that the device did not come with a wall charger, considering the price tag. On top of that, they aren't clear that it doesn't come with the charger until you read the directions, and they state that you should use a charger that has an input of no more than 5V and output of no more than .5A. The directions caution that using a more powerful charger can damage the equipment. Well, finding a charger that lets out a trickle of power is extremely difficult (I found just one on Amazon). Customer Service: I contacted customer service during the Christmas holidays, and heard back pretty quickly after Christmas was over. They offered to reimburse my charger purchase. They also bumped my question about the charger up the line, and I was told that I could use a regular charger. I bought the low-power one and was reimbursed right away. Customer service was very attentive and polite. In all honesty, that's rare these days, so I was very pleased about that. On to the device. I'm fairly sure the device I received was simply a lemon, based on the many reviews I've read. The short version is this: I tried the device for some short time periods and it seemed to work fine. Anything longer, though, and it would show that it was working but not show that it had made an activity file. I scoured the documentation for answers, tried synching the device (it would not synch), tried forcing an upload, and nothing. Eventually I got a message stating that the device memory was full, while the activity log said it had recorded just 2 hours of activity. I also had trouble with the phone app showing low or 0% battery when the device had memory in the double digits, and I had to reboot the device to get it to reconnect properly. The documentation on this is scant. It tells you how to use it (for the most part) but the troubleshooting guide read like a sales pitch rather than real help. I looked for answers in the community but found questions like mine and no answers. Customer service, again: I contacted their chat support and they were unable to help me. Instead, they asked me to set up an appointment for a video chat for onboarding. The calendar dates/times they sent were almost all in the early morning hours (from 1 AM onward) and I couldn't find a time until the following week. They then sent me an link to a calendar for tech support, with the same kinds of times. I was able to set up a meeting for 11:30 AM on Saturday. That turned out to be 11:30 *PM*, so I was all alone in the morning and missed the evening meeting. I didn't make a mistake. I was shocked that their tech support hours started at 1 AM my time and assumed it was because it's an international company, so I scheduled the time best for me. I would never have scheduled an appointment for 11:30 pm. So I gave up and returned the monitor as defective. Customer service has continued to reach out to talk with me, but I'm just not interested anymore. I will say that the device does look pretty cool, and it was great fun to watch my ecg readings scroll by. The strap was surprisingly comfortable, even though I had to tuck it under my bra to have it in the right place. Do watch the videos, because I learned more about how to wear and use the device from them than from the written guides. I was looking for the device for medical purposes, and I will say that this is definitely geared toward athletes more than medical - most of the activity types were things like running and walking. But that's ok. I don't like that my information goes to the cloud instead of, say, to my computer, but I could live with that as well. I've I'd have been able to get it to work for me, I'd have used it to try to improve my heart health as well. But alas, I was not lucky.

I purchased this to replace a ant+ and Bluetooth heart rate monitor. I have enjoyed having on hand ecg monitoring and a battery life long enough to support a full day or nights sleep. The customer service team has been truly amazing and stood by the device to help support and troubleshoot throughout out my time with the device - roughly a year and a half now.

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.

Fonctionne comme promis, mais fonctionnalités disponibles sans abonnement particulièrement réduite

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

As a long-distance runner, the Frontier X2 has been a game-changer. Unlike regular fitness trackers, it provides real-time ECG, heart rate variability, strain score, and breathing rate — all during intense workouts. I use it to monitor cardiac strain and recovery, and the data has helped me optimize my training and avoid overtraining. The chest strap is super comfortable, even on 2+ hour runs, and the battery easily lasts a full day. Syncs perfectly with the app and gives me in-depth insights post-run. If you’re serious about performance and want lab-grade data on the go, this is the device to get.

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