Frontier X2 Heart Rate Monitor Review | Next Level Data and Tracking

We’ve entered a new age of wearable fitness tracking, from smart watches and wrist straps to rings and even ear buds. Fourth Frontier is leveling up the wearable playing field with the new Frontier X2, a heart rate monitor that does more than simply track your heart rate – it can run 24/7 continuous ECG. 

The Frontier X2 features smart vibrational alerts that gently buzz when you cross preset thresholds for heart rate, breathing rate, or strain.

This allows you to adjust your intensity in real time without constantly checking a screen, helping you stay in the right training zone and protect your heart during tough sessions.

We put it to the test to find out how well it tracks and also how well it works alongside their sports bra which makes it easier than ever to attach a HR monitor.

Spoiler: Incredibly accurate readings and we loved the info!

Frontier X2 Overview

Unlike other smart watches, smart rings and other HRMs, the Frontier X2 “provides continuous ECG with real time heart health feedback even during exercise, ensuring high signal quality with comprehensive heart health monitoring during any activity.” 

The monitor also, when paired with the Frontier X App, will track your heart rate, breathing rate, body shock, HRV, and heart strain. Each workout synced to the app will give you a training load and post-workout summary, which includes all of your metrics.

If you start and stop your workout within the app, you will receive a full ECG report after your workout. There is one small caveat – any workouts that you start and stop using your running watch or cycling head unit will not give you ECG readings. 

Each workout summary also gives the user the option to add Notes and you can view key basic metrics like Total kCal burned, Training Load and it assigns a Heart Rate Strain. All these metrics are informed by your backend profile where you input your max heart rate and resting heart rate. 

When the Frontier X2 is connected to your phone or Apple Watch app and the phone/watch is carried along, it records GPS data as part of your workouts. Since the device doesn’t have a GPS chip of its own, it uses the phone’s or watch’s GPS.

You can then download a .FIT file from your Frontier dashboard and upload it manually to apps like Strava, TrainingPeaks, or JeFit for further analysis.

Alternatively, you can connect the Frontier X2 to an external HRM like Garmin or Polar and pass the data on to those platforms — the uploaded workout will include the heart rate measured by the Frontier X2.

We tested the Frontier X2 for 3 weeks and it provides an incredibly accurate heart rate read. The ECG readings and heart rate zone insights are valuable for any user, not only athletes.

The true benefit of utilizing the monitor comes over time, when you can leverage the app to get detailed physiological insights and track your heart rhythm deviations. While the experience was mostly positive, we did have a few things on our wish list.

It was a bit difficult to get the HR monitor to pair with cycling head units or running watches and then to broadcast your HR data. Sometimes you would need to first connect the monitor to the app and then disconnect it and other times it would work seamlessly, yet you need to double-click the monitor to start a workout and double-click to end the workout. 

Quick Take

Route Maps

One of the reasons many of you won’t use a HR monitor is comfort. What can I say, I know that especially in the summer it’s a potential chafing issue.

But I will say this strap is much softer than others that I use (maybe because it’s new and not stiff from sweat ewwww).  I found it easy to adjust to get the right snug fit so that it’s sitting right at the sternum and not really moving around while I run.

And of course you need to slightly dampen the pads before starting the workout to get the sensor to pick up your HR before you start sweating.

While running, I never noticed any issues with HR dropping out or skipping recording. This generally comes down to maintaining good contact and sometimes little moisture on the strap. I sweat plenty to do that.

So far this chest strap is holding up well and we’re happy with the overall comfort and fit.

Frontier Sports Bra

We also got a chance to test the new Frontier HRM sports bra – and I loved it. Simple, yet innovative, the HRM sports bra allows the wearer to simply click your monitor into the bra for comfort and convenience.

If you dislike heart rate straps like me, or you simply want one less item around your chest, this is for you. While very similar to a regular high-quality sports bra, the HRM contains a band around the bottom with integrated electrodes for easy transmission of heart rate data.

The bra has held up well through multiple washes and long days outside. It is also quite comfortable and is moisture-wicking through hotter days. The size chart was also very accurate. 

Turns out, I was pretty stoked to have a HR monitor that went above and beyond the basics.

And honestly? It’s about time. I’m happy to say that gone are the days that a running heart rate monitor does only one task (and sometimes not so well). With the Frontier X2, you get much more for one device – and at a price point that is truly manageable. 

Buy Frontier X2
Buy Frontier Sports Bra

Frontier Discount Code: RUN for 30% off

Who Tried It?

Leslie is an elite off-road cyclist who dabbles in running. While a lover of all things fitness tech, brands usually have her test products simply because she’s really, really (REALLY) good at breaking them. You can find her in San Francisco, CA, where she rides and runs through rain, fog and sun for thousands of miles each year.

What to Read Next?

• How to Find Your Maximum HR for Training
• Understanding Running HR Zones
• How to Implement Low Heart Rate Training