24/7 Continuous heart tracking during 20+ activities
Advanced heart insights like Strain, Cardiac Age & more
Accurate VO₂ Max, HRV and recovery insights
Personalised zone alerts to keep you in your target zone
£549
OR
$38/month*
×
*14-day money-back guarantee
Use code LAUNCH30 to get 30% Off
Up to 4 months* battery on a single charge
50% faster charging with USB-C and IP67
24/7 Continuous heart tracking during 20+ activities
Advanced heart insights like Strain, Cardiac Age & more
Accurate VO₂ Max, HRV and recovery insights
Personalised zone alerts to keep you in your target zone
Frontier X3 v/s Smart Watches & Smart Rings
Smartwatches and smart rings rely on optical PPG, which can be affected by movement and lead to less reliable readings. Frontier X3 uses chest-based ECG technology for more precise heart-rate data, even during intense exercise.
Optional Add On
Frontier Premium Subscription: For the most accurate VO2 Max outside a lab, Zone 2 training with VT1, VT2 Zones, Readiness Score, Oxygen Uptake, and Sleep Stage Analysis, Learn More.
HRM Sports Bra: Features integrated electrodes for external heart rate monitors like Garmin, Polar H7, Frontier X3, and more. Moisture-wicking, high-performance fabric, and standard snap compatibility (45mm distance between snaps), Learn More.
Travel Case: A durable, travel-friendly hard case designed to protect your Frontier device with custom-fit compartments for the device, cable, and chest strap, Learn More.
Free Add On, Shipping and Warranty
With Frontier X3, you’ll receive:
1 Free consultation with our expert
Lifetime customer support
1-year warranty for added peace of mind
Free Express Delivery : 3-5 business Days
Real stories that inspire us
TRUSTED BY 30K+ USERS IN 50+ COUNTRIES
Paula Radcliffe
Former Women’s World Marathon Record Holder for 16 years
The first run I had with the device showed me how comfortable, simple, and easy to use it was, but more importantly, it gave me reassurance after years of pushing my body and my heart to its limit, that I hadn't caused any lasting damage."
Mark Dutton
Frontier device user
The Frontier Device has just given me an incredible level of clarity and detail about my heart during prolonged endurance events and you just can't get that kind of detail with other devices. It helps me dispel fear and uncertainty.
Filip
Frontier user, lawyer & athlete
Frontier Device Tracks your inherent abilities and keeps you safe. It's a must have and it's something that I just don't train without anymore.
Elizabeth
Frontier device user
I like that it has the vibrating alert when I'm going too hard, so I don't need to be looking at my device while I am pedalling and take my eyes off the road.
Darren Mott
Frontier user, Former FBI agent
The Frontier device which helps me monitor what I'm doing and gives better representation of the stress on my heart during various activities.
Scott Kaintz
Frontier device user
Frontier Device has been extremely powerful. Effectively I wear it for all exercise and while sleeping. It's nice to have a data collection tool that I can put on during those periods.
Mark Allen
6 x Ironman World Champion
The Frontier device is an amazing device that helps you tune into some of that stuff that may be hard to tune into. Your heart will never say ‘hey I’m getting a little tired here – you won’t know you’ve gone to the far end of danger until it’s too late. Your heart cannot give that kind of feedback, but the Frontier device can.
Tom Gaskell
Wind Surfer, Frontier device user
Without the Frontier device we never might have known that increasing your exercise burden beyond a point puts excessive strain on your heart. I would have probably increased my exercise: done more, for faster and longer, and this could have impacted my health negatively.
Howard Dyson
Cyclist, Frontier device user
The Frontier device helps me recognize what I am feeling, giving me opportunities, in certain instances, to push my boundaries, that are then reflected in me.
Jeremy Dirom
Frontier device user
I am super impressed with the Frontier device not only does it work well as a heart rate monitor, but it does a great job of collecting other data…
Daniel Chernoff
Frontier device user
I like to measure my heart rate during paced workouts so I know what zone I'm in and also the measurement of strain and training load are unique to the device.
Terry Gardiner
Frontier device user
I want to make my life better, my heart better, I really learned a lot from the data, I felt a lot more confident, and better kind of kept at it.
Helen Brown
Frontier device user
I like that it has the vibrating alert when I'm going too hard, so I don't need to be looking at my device.
Rod Groomes
Frontier device user
Frontier device allowed me to monitor my heart rhythm continuously and receive instant feedback, instead of waiting days or weeks for results.
Greg Bongen
Frontier device user
After using the device for over 2 years and cycling 8,000 miles annually, Greg shares how the Frontier device helped him monitor his heart health, detect anomalies, and take proactive steps with his healthcare professionals.
Joe DePinto
Frontier device user
A couple of years ago, I started seeing some online reviews about the frontier device, really checked all the boxes for me that were important. somebody who's an older runner hook for me to purchase was the strain measurement, I hadn't seen that in any other device.
Walther Ramos
Frontier device user
The Frontier has been amazing because it has helped the doctors at Northwestern , figure out a way to give my life back and be comfortable with me working out two hours a day.
Certifications
Features
VO₂ Max Trends
Follow changes in VO₂ Max over time to understand how your aerobic fitness is progressing with training.
Gold Standard Heart Rate
Chest-based ECG captures a more reliable signal during intervals, sweat, and high movement.
Cardiac Age Trends
Compare your heart’s functional age with your actual age and track changes over time.
Strain Monitoring
Gauge the cardiovascular demand of each workout and how hard your heart was working throughout the session.
Training Load
Track cumulative workload to balance training, recovery, and progression.
Body Shock
Track activity impact to understand stress on your joints and musculoskeletal system.
VT1–VT2 Based Zones
Train with zones based on ventilatory thresholds, not estimated heart-rate ranges
Zone-Based Alerts
Personalised vibration alerts help keep your heart rate within your selected training zone.
Track 20+ Activities
Track heart and performance metrics across running, cycling, rowing, hiking, and more.
Session Metrics
Review pace, distance, duration, and heart metrics in one session view.
Activity Tagging & Notes
Add notes and tags to capture workout context and conditions.
Advanced HRV Insight
Follow HRV trends to understand recovery, fatigue, and adaptation.
Readiness Score
Know how prepared your body is for training each day and match workout intensity to your current state.
Sleep Stage Analysis
Track Wake, Light, Deep, and REM sleep to understand recovery and sleep quality.
Stress Monitoring
Track stress levels through HRV and related signals to understand your recovery state.
Wrist-based data fails when you need it the most
Your resting heart rate sets the baseline for fitness and recovery. Chest-based ECG detects the electrical signal of each heartbeat directly, while wrist PPG estimates pulse from changes in blood flow, making ECG a more direct measure of heart rate.
Zone 2 training works best when your heart rate stays within a specific range. Chest-based ECG reads each heartbeat from the heart’s electrical signal, giving a steadier reading during movement, while wrist PPG can fluctuate with motion and sensor contact.
Near Max HR, accurate heart-rate data helps you judge how close you are to your upper limit. Chest-based ECG captures each heartbeat electrically, while wrist PPG can show greater variation as movement and intensity increase.
Chest-based ECG vs Wrist-based PPG
0.0bpm
Difference in Average HR Error
Chest-based electrical (ECG)
VS.
0bpm
Difference in Average HR Error
Wrist-based optical (PPG)
A Cleveland Clinic research found chest-worn monitors are more accurate than wrist-worn monitors. Frontier X3 uses chest-based ECG technology for precise heart-rate tracking during exercise.
Why Frontier X3
4 Months* battery on a single charge.
IP67 Rated
Faster sync, seamless transmission
10% lighter than previous generation
Go beyond heart rate monitors and smartwatches
Features
Other HRM
Smart Watch
HR and HRV
The number of heartbeats per minute (BPM), indicating the intensity of cardiovascular effort.
Training Load
Total physiological work based on time spent in various breathing rate zones.
VO2 Max
Measure how efficiently your body uses oxygen during exercise
Precise Zone 2 Training
Training at a defined aerobic intensity that maximizes endurance gains with minimal fatigue.
Body Shock
Measures stress on joints and musculoskeletal system
Strain Monitoring
Measures cardiovascular strain during any activity.
Zone based alerts
Get discreet real-time vibration alerts to keep you in the optimal zone.
Real time Vibration alerts
Get discreet real-time vibration alerts to keep you in the optimal zone.
VT zones
Measures when your body shifts from aerobic to anaerobic exercise
*Frontier Premium includes a 7-day risk-free trial with a money-back guarantee if you're not satisfied by the end of the trial period.
FAQs
What is Frontier X3?
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.
What makes Frontier X3 different from a regular heart rate monitor?
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.
Why does Frontier X3 measure from the chest instead of the wrist?
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.
How accurate is the heart rate measured by Frontier X3?
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.
Does Frontier X3 have a Live ECG feature?
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 at a rate of 500 Hz 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.
What is the battery life of Frontier X3?
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.
How long does Frontier X3 take to charge?
Frontier X3 uses USB-C fast charging and takes approximately 1 hour for a full charge, making charging around 50% faster than Frontier X2.
Can I use Frontier X3 without my phone?
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
Can Frontier X3 connect to other fitness devices?
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+.
What activities can I track with Frontier X3?
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.
What heart and performance metrics does Frontier X3 track?
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.
How can Frontier X3 help with training and recovery?
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.
Can Frontier X3 track sleep and recovery?
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.
Is Frontier X3 waterproof?
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.
Is Frontier X3 comfortable to wear for long periods?
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.
What is the difference between Frontier X2 and Frontier X3?
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 Explore more
Is Frontier X3 a medical device?
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.
Disclaimer :
The Frontier X3 is not a medical device and does not diagnose or treat medical conditions. It is intended for general wellness, fitness, and performance insights. Always consult a healthcare professional before making changes to your health or fitness routine.
