TechRadar review: Frontier X2 is accurate but expensive heart rate monitor

The chest strap uses electrodes to provide continuous ECG functionality and delivered readings comparable to top-end wrist-based wearables, TechRadar said. The screen and tactile button help users confirm the device is on and connected, a common pain point for some chest-strap heart rate monitor users, according to the review. The device is USB-rechargeable and provides haptic feedback when users cross heart rate zone thresholds. TechRadar said the screen cannot be viewed while the strap is worn on the chest, but it makes workout preparation and phone connection easier than with the Polar H10.

The review compared the Frontier X2 with the Polar H10, which TechRadar described as an accuracy benchmark for athletes but also a device with connectivity issues, no on-device interface or controls, and a cluttered, outdated app. TechRadar’s reviewer said the Frontier X2’s more modern app and physical controls made it easier to start a workout and check that heart rate data was streaming before exercise.

The Frontier X2 uses heart rate information to calculate metrics including a Strain score, Stress score, heart rate variability, breathing rate and estimated calories burned, TechRadar said. The review noted that Stanford University research found calorie estimates based on heart rate unreliable because they measure effort rather than energy expended. A premium subscription costing $119.99 or £109.99 per year adds a Readiness score, VO2 Max and sleep stage analysis. TechRadar said it would not recommend the subscription unless the Frontier X2 is a user’s primary fitness tracker and accuracy is especially important.

The continuous electrocardiogram can livestream an ECG scan to the Frontier app for the user or a medical professional, according to the review. TechRadar said this is useful for spotting irregular heart rate rhythms over time, and the reviewer often used it to confirm the monitor was streaming data correctly before starting a workout. The app flags insufficient data caused by poor connection, the review said.

In accuracy testing, TechRadar compared the Frontier X2 with the Apple Watch Ultra 4, which the review said offers a redesigned Health Sensing System described as “the most accurate ever on a wearable,” and the Garmin Fenix 9 Pro, which uses Garmin’s Elevate V5 sensor. The Frontier X2’s average heart rate readings were separated by just 2 bpm from the Apple and Garmin devices, a result TechRadar said indicated all three devices were likely accurate. After additional solo runs and workouts, the reviewer said the Frontier X2 could be recommended to users who do not mind paying the premium price.

The Frontier X2 costs $599 in the US, £449 in the UK and AU$775 in Australia, TechRadar said, and is sold through storefronts including Amazon and, in Australia, Selfridges’ AU storefront. The review described the price as very expensive for a heart rate monitor and said the optional subscription is difficult to accept at that price, especially compared with the Polar H10 at $89.95, £79.50 or AU$139. TechRadar also listed the lack of ANT+ support and features locked behind the subscription paywall among drawbacks.

Editor's Summary

TechRadar’s review positions the Frontier X2 as a high-accuracy chest-strap heart rate monitor with continuous ECG, on-device controls and useful app feedback. Its main drawbacks are the $599 price, lack of ANT+ and a subscription for advanced metrics, making it a niche option for users who prioritize accuracy and are willing to pay for it.