Frontier X3 is a chest-worn heart and fitness monitor designed for people who want deeper insights into their heart health, training, and recovery. It captures heart data directly from the chest and tracks metrics including Heart Rate, HRV, Breathing Rate, Strain, Training Load, Body Shock, and more.

Frontier X3 goes beyond simply measuring fitness and recovery metrics. Its chest-based technology captures detailed heart data and turns it into insights you can act on during training and over time.

It provides metrics such as Strain, Body Shock, VT1–VT2 Zones, HRV and VO₂ Max trends, Cardiac Age, and more. You can also set zone-based, and metric-based alerts, with real-time vibration feedback when you cross your chosen thresholds.

This combination of deeper heart insights, long-term trends and real-time feedback helps you better understand how your heart and body respond to effort, recovery and training.

Frontier X3 uses chest-based ECG technology to capture the heart's electrical signal for better accuracy. Unlike wrist-based optical sensors, which can be affected by movement, sweat and changes in skin contact, chest-based measurement provides a more reliable signal during high-intensity exercise.

Frontier X3 offers up to 4 months of battery life on a single charge, based on typical use of around 1 hour per day, or up to 14 days of continuous recording on a single charge. Spend less time charging and more time tracking your heart health and training performance.

We wanted to maintain a clear distinction between our medical and wellness products. Since ECG in our non-medical products cannot be used for diagnostic or other medical purposes, the raw ECG data is not available in the Frontier X3 device.

However, internally, the Frontier X3 is actually sampling the ECG data and calculating all metrics — HR, HRV, BR, Strain, etc. — from the ECG data recorded from the chest strap.

The raw ECG display feature is available in our FDA-cleared medical device, Frontier X Plus, and this data can be used for medical purposes.

Frontier X3 offers up to 4 months of battery life on a single charge, based on typical use of around 1 hour per day, or up to 14 days of continuous recording on a single charge. Spend less time charging and more time tracking your heart health and training performance.

Frontier X3 uses USB-C fast charging and takes approximately 1 hour for a full charge, making charging around 50% faster than Frontier X2.

Yes. Frontier X3 can record your activity without being continuously connected to your phone. Your data can be synced to the Frontier app after your session.

If GPS data is required for your activity, use Frontier X3 along with your smartphone or GPS-enabled smartwatch

Yes. Frontier X3 uses Bluetooth 6.0 and can connect to compatible Bluetooth-enabled fitness devices.

It supports up to 3 simultaneous connections: 1 phone and 2 external devices.

Frontier X3 does not support ANT+.

Frontier X3 supports 20+ activities, including running, cycling, rowing, hiking and other indoor and outdoor workouts.

Its chest-worn design allows it to capture heart and performance data even during high-movement activities.

Frontier X3 provides insights across heart health, performance, and recovery, including:

• Cardiac Age Trends, Heart Rate, Breathing Rate, Heart Rate Variability (HRV), Recovery, Training Load, Calories Tracking, Strain Monitoring, Zone 2 Training, Heart Rate Zones, Step Cadence, and Body Shock.
  
  
• Additional advanced insights such as VO₂ Max, Oxygen Uptake Zones, Ventilatory Threshold Zones, VT1–VT2 Training Zones, Readiness Score, and Sleep Stages Analysis are available through Frontier Premium.

Frontier X3 helps you understand how your body responds to exercise and recovers over time. It combines heart rate, HRV, breathing rate, strain, and training-load data to provide insights into your exercise and performance. 

The Readiness Score helps you understand when your body may be ready to push harder, when to reduce training intensity, and when to prioritize recovery. Sleep Stage Analysis provides insights into your sleep patterns to help you better understand your recovery and make more informed training decisions.

Yes. Frontier X3 can be worn for longer periods, including overnight. With supported Frontier Premium features, you can track Wake, Light, Deep, and REM sleep stages, alongside HRV and recovery insights. 

The Readiness Score helps you understand how prepared your body may be for physical activity, so you can make more informed decisions about training intensity and recovery.

Frontier X3 is IP67 rated, making it resistant to sweat, rain, and temporary water exposure. It can withstand immersion up to approximately 1 metre of fresh water for up to 30 minutes. 

However, it is not designed for prolonged underwater use and is not rated for saline water. For swimming, wear Frontier X3 under a tight-fitting suit to help keep it securely in place.

Frontier X3 weighs approximately 23 grams, making it around 10% lighter than Frontier X2. Its screen-free, low-profile design and breathable chest strap provide a comfortable, secure fit for workouts, daily activities, overnight wear, and longer recording sessions.

Frontier X3 builds on the heart health and performance tracking capabilities of Frontier X2, with upgraded hardware, improved charging, and a lighter, more streamlined design for greater convenience during everyday use and training.

Key upgrades in Frontier X3 include:

• Up to 4 months of battery life on a single charge (1 hour/day use)
• USB-C charging with 50% faster charging
• 10% lighter design
• Bluetooth 6.0 for enhanced connectivity
• Screen-free, low-profile design for distraction-free wear
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No. Frontier X3 is designed for fitness and general wellness purposes. It is not intended to diagnose, treat, cure or prevent any disease or medical condition.

Information provided by Frontier X3 should not be considered a substitute for professional medical advice, diagnosis or treatment.