Frontier X review: Advanced heart rate monitoring

Malefemalerun Frontierx
(Image: © Darshan Manakkal / Fourth Frontier)

iMore Verdict

Bottom line: Frontier X offers the latest and greatest in advanced heart rate monitoring. Features include live ECG, tons of heart-based metrics, vibration alerts, sharing capabilities, and records. On the downside, it's incredibly pricey, it doesn't count calories, and there's a steep learning curve to maximize your usage.


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    Advanced ECG

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    Heart-based training metrics

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    Vibration alerts

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    Share ECG and other metrics

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    App tracks, records, and emails all data


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    Very pricey

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    Lots of data to crunch

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    Frequent updates/updates take valuable time

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    Doesn't record calorie burn

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Heart rate monitoring is vital for a multitude of reasons. It's an indicator of the intensity of effort and your body's physiological response. It's an integral component of fitness assessments and training programs. Keeping tabs on your heart rate and personal heart rate zones equates to excellent heart health and reaching your health and fitness goals. Frontier X is an advanced heart rate monitor that offers ECG and all kinds of heart-based data to assist your training needs.

Frontier X: Price and availability

Frontier X

Frontier X (Image credit: Nicolette Roux / iMore)

Frontier X is currently available on the Fourth Frontier site for $499. It comes with the Frontier X heart rate monitor, two chest straps, one micro-USB charging cable, a quick start guide, and two silicone protectors for the USB port.

Frontier X: What's good

Frontier X

Frontier X (Image credit: Nicolette Roux / iMore)

As a master fitness instructor and someone who has worked in the health and fitness industry for over a decade, I firmly believe in heart-based training. It's the most effective way to track calorie burn and training loads to achieve your health and fitness goals. Maintaining good heart health is essential for everyone's longevity, so it's worth keeping tabs on.

Frontier X offers tons of heart-based metrics and up to 24 hours of continuous ECG.

Frontier X isn't your average heart rate monitor. It's one of the most advanced heart rate monitors I've come across. It offers continuous ECG monitoring and tons of heart-based metrics. There is a lot of data to crunch with this device and companion app. One might say a little too much, but Frontier X works in tandem with the Frontier X app to deliver valuable information if you're willing to put the time into understanding and utilizing it.

Advanced ECG monitoring enables the user to continuously record ECG for up to 24 hours during any activity (including sleep). You can also take a live ECG test anytime and are able to share these metrics immediately. Why monitor ECG? Well, monitoring your ECG identifies and alerts you to any rhythm irregularities and is a quick way to analyze your current cardiovascular health.

Frontier X works with the free Frontier X app to evaluate your heart-based metrics throughout the day. In the app, you'll find your training history, training load for the week, weekly goal, AI personal recommendations based on your profile, activity analysis, and community forums. Recordable activities include running, cycling, walking, indoor running, indoor cycling, strength, circuits, aerobics, boxing, hiking, rowing, skiing, sleeping, general sports, swimming, triathlon, yoga, etc. No matter the activity, X has got you covered.

Frontier X

Frontier X (Image credit: iMore)

For every recorded activity, you'll see your training load. The duration of your workout. Your heart rate, cardiac strain, body shock, breathing rate, HRV (heart rate variability), and your step cadence, if applicable. I told you — lots of data to crunch. It also offers connected GPS and will map your routes if your smartphone is on you. When you click on an activity in your history, you can view your physiological metrics timeline graph. This will open a detailed graph of your workout, where you can switch between tabs to see how the different parameters varied throughout your session or compare them in the comparison view.

You can add health event tags to any activity to help you understand how lifestyle choices and behavior affect your heart health. The health event categories include medication, beverage, food, supplement, body status, mental status, wellness activity, and environment. There are many sub-categories beneath those general health event categories. If you're interested in knowing how your lifestyle and behavioral choices affect your cardiovascular health, this is an opportunity to get a very detailed understanding.

For each recorded activity, you can set vibration alerts, compare parameters, and add event tags.

While monitoring an activity, Frontier X will send real-time, personalized vibration alerts to keep your training on the right track in the proper zones. You can edit your alert settings and choose parameters for when you would like to receive a single or double buzz. You can choose between heart rate, breathing rate, or cardiac strain. You can also set upper and lower limits. Selecting an upper limit will give you a buzz every 20 seconds if you are above the upper limit threshold. Choosing a lower limit will buzz you every 20 seconds you are below the lower limit threshold.

Frontier X claims to offer 24 continuous hours of battery life and 12-15 days under typical usage. My experience has been a bit less than that. I've gone from close to 100% out of the box to 15% in exactly one week. It takes 45 minutes to charge fully. The Frontier X app is compatible with iOS and Android phones and Apple Watch.

Frontier X: What's not good

Frontier X Data

Frontier X Data (Image credit: iMore)

Frontier X is very pricey. In its defense, it does track, record, and deliver more cardiovascular data than any other wearable I've come across. That being said, the amount of data presented is overwhelming, difficult to understand and utilize. At least, that was my experience. There's a steep learning curve, but if you're willing to dedicate the time and energy, I could see it as a valuable tool over time.

Frontier X is exceptionally pricey, updates frequently, and doesn't record calorie burn.

In the short time, I've used this device (one week), it's updated five times — almost every time I tried to record an activity. These updates had to happen before I could start, and they each took five to 10 minutes. Sometimes, I only have 20 minutes to squeeze a workout in when I'm busy. The constant updates were frustrating, as they ate up valuable time I could have spent sweating.

Something I find odd about this device is that it doesn't record calorie burn. Now, calorie burn isn't the most crucial performance metric, but it's by far the most driving for me. I like to see where, when, and how many I burn every workout. Frontier X tracks such an abundance of activity metrics, and I was shocked that it doesn't track this one.

Frontier X: Competition

Polar H9 Lifestyle

Polar H9 Lifestyle (Image credit: Nicolette Roux / iMore)

Polar H9

I've tried and reviewed the Polar H9 heart rate monitor. It boasts a similar design and gives accurate readings. When paired with the Polar Beat app, it grants users access to over 100 workout profiles, where you can track and store your workout routes, calories burned, and the duration of your training sessions. It's a lot less expensive than Frontier X but doesn't come close to offering all of the advanced heart-monitoring features the X does.

Scosche Rhythm Plus 2 Front

Scosche Rhythm Plus 2 Front (Image credit: Christine Romero-Chan / iMore)

Scosche Rhythm Plus Armband

The Scosche Rhythm Plus Heart Rate Monitor Armband sports a different design. Rather than wrapping around your chest, it's worn on the arm. Some might say an armband is more comfortable to wear, while others say chest straps give more accurate heart rate readings. Whatever your personal preference, this armband is much less expensive than Frontier X but doesn't offer nearly the number of features.

Frontier X: Should you buy it?

Frontier X

Frontier X (Image credit: Nicolette Roux / iMore)

You should buy this if ...

  • You want continuous ECG
  • You're a serious athlete or training for a major athletic event
  • You're into advanced heart-based metrics

You shouldn't buy this if...

  • You're looking for a basic heart rate monitor
  • You're on a budget
  • You want a calorie counter

You should buy this if you want continuous ECG monitoring. Frontier X offers up to 24 hours of continuous ECG and enables the user to take a live ECG reading whenever they choose. If you're a serious athlete or training for a major athletic event, you could greatly benefit from this advanced heart-based data. You shouldn't buy this if you're on a budget and just want a basic heart rate monitor. Many highly accurate heart rate monitors on the market are far less expensive than Frontier X. Please note that the X tracks and records many cardiovascular metrics, but calories are not one of them.

Frontier X is an advanced heart rate monitor that delivers valuable cardiovascular metrics to help you maintain excellent heart health and reach your health and fitness goals. I'd recommend this device to professional athletes, those training for major athletic events, and those interested in getting an in-depth look at how lifestyle and behavior choices affect their cardiovascular health. It's pricey, doesn't count calories, and there's a steep learning curve, but if you're serious about heart-based training, it's worth checking out.

Nicolette Roux

Nicolette is a freelance writer for iMore. She's been hooked on Apple products since she got the very first iPhone in 2007 and made the switch from PC to Mac in 2008 after inadvertently dousing her laptop with a hefty dose of water. A dedicated creative, Nicolette has had the pleasure of working with some of the top websites, studios, and brands in the industry throughout her career, and enjoys writing about all things: Apple, health, fitness, audio, and home. With over a decade of high-level experience as a health and fitness professional, Nicolette specializes in tech pertaining to the field. If she’s not working, you can find her sipping a glass of wine, enjoying a concert, or hanging with her family.