Fourth Frontier Reviews 362

I bought this (Frontier X Plus) to monitor PVCs that I was having and try to determin the burden from them over period of rest and workout activity, walking etc. My physician ordered a 2 week patch monitor which did not come even after two weeks. I ordered this and had it up and running in a week and it works as advertised. They only classify PVCs as Inconclusive. Only AFIB is positively identified as well as Bradycardia and Tachycardia. For my use - Inconclusive is basically telling my I have irregular rhythm and its PVCs in my case. Works well, occasionaly with dry skin - it says unreadable - but a slight moving and resetting of the strap brings it back online. It works for 8-10 hour sleep monitoring or just an hour of interval training or yoga. All the things I cannot do with just my Apple watch or Whoop.

I’ve been using the Frontier X2 Smart Heart Rate Monitor chest strap for about six months, and it’s become a key part of my daily routine. I use it across a wide range of activities—Peloton Bike+, running, stretching, meditation, HIIT, yoga, indoor and outdoor cycling, and strength training. I also deal with heart rhythm issues, including arrhythmias, PACs, PVCs, possible AFib, and occasional pauses, so having consistent, reliable monitoring is important to me.

What stands out most is its ability to track heart activity during sleep. It captures every beat and provides detailed insights like heart strain, HRV, and sleep stages (awake, REM, light, and deep). The strap is very comfortable, even overnight, and the battery lasts several days with heavy use. The data has been incredibly useful in helping me evaluate whether my lifestyle changes are actually making a difference.

One of the biggest takeaways for me has been seeing how well my treatment is working. The device has helped confirm that my medication is effective—and more importantly, that my CPAP therapy has made a huge impact. I was diagnosed with obstructive sleep apnea (OSA), which likely contributed to my heart rhythm issues. Despite being fit and having what my doctors call an “athlete’s heart,” this had gone undetected for years. Since starting CPAP, my arrhythmia burden during sleep has dropped from around 70% to about 7%, and it continues to improve.

I also use a Kardia 6L, which is great, but it doesn’t provide the same continuous tracking or depth of data as the Frontier X2.

As a web applications developer, I really appreciate the software experience. Both the mobile app and the web dashboard are clean, intuitive, and recently updated. The interface makes it easy to understand the data, and I especially like how it clearly flags arrhythmias so you don’t have to manually scan through ECG recordings.

Yes, it’s a bit pricey—but in my opinion, it’s absolutely worth it. I was so impressed that I even bought one for a friend who’s a nurse and nationally certified ECG technician at Kaiser. I also pay for the yearly subscription, and I find it well worth the cost.

Overall, I’m genuinely glad a device like this exists. It’s given me real insight into my heart health and helped me track meaningful progress. If you’re considering it, I’d definitely recommend it—you’ll likely love it as much as I do.

This is an important device to monitor my progress. I use it almost every day to track individual workouts. In addition I have worn it overnight to track my heart rate during sleep (once a month). This is a high fidelity measurement device coupled with software to track trends both individual workouts and week/month trends.

Really good product! Up there with the best heart rate monitor on the market! Solid data with ECG recording capabilities! Customer service is top notch. The APP is user friendly!
Definitely worth trying out for yourself and highly recommended!

Prompt, courteous service

I have had my device, the Frontier X 2, for almost two years now. Over that time, I had an issue with the device rectified quickly following some email communication with their support team, who helped me reset the device. I have also had a couple of live Zoom/Teams calls with them to discuss the results I was getting with the device, which I was unclear about. They have always been quick to answer my support questions, and they even accommodated times for the live calls outside of their normal hours, which was great. I use the device at least 4 days of the week when training, and I am overall very happy with my purchase.

Product did not work for me. Kept getting noise in my data regardless of what I did spending time with Customer support. However the customer support team was extremely responsive, polite and accommodating. This would have been zero stars without their support and help. Resulted in full refund of my cost. Now receiving calls from customer support to change or remove my review. So dont trust the reviews you do see. There are other products out there try one of them.

The response to my inquiry was prompt and thorough

Very friendly, kind and customer focused support. My technical issue was picked up and solved very quickly.

Excellent product, I had Afib and it helped me to understand which activities brought it on, sleeping and exercising in my case. This also helped me make the decision between medication and ablation. Customer service is also top notch. Quick response times very knowledgeable.

I’ve been using the FrontierX HR monitor for nearly 6 months. Firstly to track a mild exercise induced atrial arrhythmia which I then shared with the cardiologist who was then able to diagnose together with stress ECG. Secondly to better define my training zones via breathing rate / metabolic analysis for VT1 and VT2 for triathlon. I used the online fourth frontier analysis tool together with my own ramp tests and FTP tests to nail my “easy”, “moderate” and “hard” intensity zones with power, heart rate and breathing. Very powerful- to the extent that pro-cycling teams are doing this now. Easy is now easy and hard is hard. No straying into grey moderate workouts. This helps to recover faster and maintain training load. I’ve had a few issues - mainly software and reboots - but customer service is really fast and very high quality in terms of troubleshooting and fixes. Given the accuracy and precision of the monitor I’m amazed at how small, durable (I’m a heavy sweater) and robust it is. Overall very good!

I bought the X plus with the goal of full-time AF monitoring. I run frequently and wanted to know if arrhythmias were related to exercise as well. I have been disappointed in both, but mostly for running. Almost every run, the X plus wil start out recording, then show “unrecordable” or will be unable to interpret the rhythm, “indeterminate”. I have abandoned the X plus and now wear my Apple Watch 24/7 and it gives me Afib burden. This is more useful than the X plus. X plus is a great idea gone awry: great hopes but poor delivery. Support suggestions were not of much use. My Apple Watch has been much more reliable, even though Apple Watch does not monitor full-time and could miss a brief AF episode.

This device probably saved my life. The doctors were dismissing my concerns until I gave them hard evidence. The support group is really helpful. I gave them 4 stars for two reasons. One, the android app is buggy. Sometimes it connects to the chest strap connects right away, sometimes it doesn't. Sometimes the app is responsive and sometimes it freezes up. The other reason for losing a star is the marketing. I was under the impression that more features were available without a premium subscription. I am tired of tech companies always telling you all the great things they do only for you to find out it costs more money.

Amazing product. With a ECG during workouts gives a lot of insights to the heart.

I was not seeing data i expected. The tech team quickly identified the issue and provided a recommendation.

I've been using my X2 for several years, and have encountered a few challenges (mostly software related). Every time, the service team is on it. They fully research and respond to every request - that's incredible! It's more than an HRM, and it allows me to continue pushing my physical limits while keeping an eye on my artificial heart valve. Thank you.

Fundamentally it should be and has been a great device, genuinely one of the best training tools I have used. I have owned both Gen 1 and Gen 2 and loved the previous interface. Had them for some time.

However, the recent website changes have significantly reduced its usability.

• Reviewing individual recordings is now much harder than it used to be
• The new interface feels like a major step backward
• It is far less intuitive to dig into specific results
• Previously I could use a drop in heart rate or an algorithm flagged event as a cue to scan the corresponding ECG above on the same screen dragging my mouse across until the lined up
• It was slightly clunky, but once you understood the workflow it worked well
• Now premium locked features sit between the heart rate graph and the ECG view
• You can no longer easily view both on screen together for interpretation

That was the core value of the platform. Without seamless alignment between the heart rate graph and the ECG trace, the tool becomes dramatically less useful.

In its current state, I cannot recommend it. The hardware remains excellent, but the software experience has undermined it. 2/2 stars for hardware, but in terms of outputs, its rendered very near useless in its current form, as its bit like pin the tail on the donkey to find the relevant 20 second strip. 1/3 for that for a total of 3, which is generous given the silly prices for this kit. Currently NOT good value at all. Best avoided unless this gets fixed.

Edit 9/2. The interface appears to have improved.And I can now drag the HR graph to right below the ECG, as it used to be. This is much better. The frustrating "drag and zoom" function appears to have improved too. IT was allowing you to zoom on both x and y axis meaning it was very easy to lost perspective of the graph. This too has been fixed. Score adjusted up 1.

Amazing product which i always wanted to buy. And got the delivery within 4 days after placing the order.

However the device wasn't recodring any activity to which I mailed the support system and they resilved the issues withing few hours.

Great experience and happy me 😊

I bought the Fourth Frontier X2 on the recommendation of my cardiologist. I’m a runner with a history of ventricular tachycardia, so the ability to take live ECGs during runs and send them to my doctor sounded incredibly valuable.

Unfortunately, the reliability has been extremely disappointing — especially given the price and the fact this is marketed as serious health tech.

In under a year, the problems started. The magnetic charging point became rusty from sweat (something you would expect to be tested against in a wearable designed for exercise). Customer service told me to use a USB charger instead.

Next came connectivity issues — the app couldn’t receive data from the device. I was offered a refurbished replacement, which worked for a while, but then more faults developed:

Finishing an activity and trying to stop recording would freeze the app, which continued recording indefinitely. The only way to stop it was to uninstall the app completely.

Activities would randomly stop recording mid-run.

Sometimes the device wouldn’t turn on at all.

It has been one issue after another. This is an expensive piece of kit that’s meant to provide dependable health monitoring, yet I’ve found it stressful and unreliable — the opposite of what you need when using a device for heart monitoring.

I really wanted this to work, but based on my experience, I would not recommend it.