Bought what I consider to be a very expensive heart rate monitor, only to receive a clearly used item. It had signs of use (grime from prior owner) as well as a charging cable that was not OEM (magnetic connection type thay connects to multiple usb tip types. It acrually had the prior owner's USB tip still in the monitor itself. I did not get the protective plug for the charging port when not charging. After first use, the device basically bricked and will not take a charge. I can't speak to any follow up, but this is either a shady business practice or really terrible quality control, or possibly both. Be wary of purchasing as other users have reported receiving used items as well with no up front disclaimer. **Update** The company did resolve the situation to my satisfaction by offering a full refund of the purchase price. I am still disappointed in the situation, but pleased they were agreeable to a resolution.

I really want to give the X2 a 5* review as there's so much I like about it. It's my third heart rate monitor and, overall, it's by far the best. I love the ECG function and additional data it provides. Although it comes at a price, I think it's probably worth the extra as there's nothing else to really compare it to. It seems well made, it's nicely presented. It connects to my devices without a hitch (I've had others that should but don't) and the after sales support seems good. The only reason it drops a star is that it can be a bit glitchy. I've had intermittent problems getting it to charge. Sometimes it reports a 'noisy' rhythm (as much as 50% of the workout info can be unusable due to interference) and the app itself can be a bit hit and miss when it tries to sync. Generally it's okay and catches up with itself and I've only ever lost one workout completely. When it works well (which is most of the time to be fair), it's really, really great and I recommend it but be aware of the glitches.

I have had nothing but a bad experience with this company. I bought a monitor on Jan 9th. When received the box stated that it was used/like new. I contacted support and heard nothing from them for about 5 days and had to follow up. I agreed to keep the device if the warranty would cover it, which they said yes. On second charge of the unit, It took over 9 hours to fully charge (manual states 3 hours). Contacted support, had a video call which was basically me just plugging in the device a few times to which they told me the unit should now be fixed. After the third charge, the unit would no longer connect to 3rd party apps. I must to connect it to their app (which was stated on the device screen). when trying to close the app, it stated that I had to disconnect the device but it was disconnected. I contacted support yet again. I was asked to have a video conference, which I could not, due to my work schedule. I sent them videos of the issue and was told I would hear back in 24 to 48 hours. It's been 5 working days and still no response. Its now May 3. and I have a very expensive faulty device. I have been dealing with this for about 3 months now. I was excited to tey this HR monitor out but it has been nothing but frustrating

I had a charging issue, reported it to FF and within a day got a very helpful response. Reassuring to know that there is always somebody to help you.

I've been using the Fourth Frontier X2 HRM for a little over 18 months, following some concerning heart behaviour during exercise. Recently I was having problems getting reliable data from the strap on occasion, leaving doubts about whether the problem was me or the strap. Yesterday I took part in a video conference with the support team, including a cardiologist. I'm not sure how long the call lasted - it was a good while - and the team really bent over backwards to sort things out and review my data. I do have an appointment coming up for a heart health review and the cardiologist very kindly prepared an email with selected heart data to send to my own doctor. All in all it was an amazing support experience. If I run into further problems the team is keen to help out again. Brilliant!

Customer. Service and support are beyond excellent. I highly recommend the Fourth Froniter Chest strap monitor. The Fourth Frointer heart rate, heart strain, breaths per minute, and training load chest strap monitor are invaluable to a serious endurance athlete. I am a Certified Metabolic Breath Testing and Data Analysis. The metrics The Fourth Frontier monitor is the next best thing to Metabolic Breath Testing and Analysis in a lab. Below is a breakdown of all the metrics it provides. Here's a breakdown of how monitoring those metrics provides valuable guidance for exercise and endurance training: Heart Strain Zones What it measures: Heart strain goes beyond just your heart rate at a given moment. It incorporates how hard your heart works over time, considering the intensity and duration of your exercise. Benefits: Identifying overtraining risk: High heart strain can indicate when you're pushing too hard and need more recovery. More precise training: Understanding strain lets you tailor workouts to individual needs, as fitness levels impact how much strain a person can handle. Heart Rate Zones What it measures is your heart rate as a percentage of your maximum heart rate (HRmax), divided into zones 1-5 based on intensity. Benefits: Targeting specific goals: Each zone aligns with different physiological benefits (fat burning, endurance building, speed development, etc.). Pacing guidance helps you stay in the optimal range during different types of workouts (e.g., long easy runs vs. interval sessions). Breathing Zones What it measures is the rate and depth of your breathing, reflecting metabolic shifts during exercise. Lower intensity generally means calmer breathing, while higher intensity makes breathing labored. Benefits: Real-time intensity check: Helps reinforce heart rate zones. Difficulty speaking indicates a transition into higher zones. Aerobic training optimization: Staying in a moderate breathing zone helps target the ideal pace for endurance building. Training Load It measures the cumulative stress your body experiences from exercise sessions. It accounts for the intensity, duration, and frequency of your workouts. Benefits: Balancing work and rest: Helps you plan training cycles, progressively overload workouts, and ensure enough recovery time. Preventing injury: Tracking training load can alert you to potential overuse before serious issues occur. How They Work Together Monitoring all these metrics creates a comprehensive picture of how your body responds to exercise, enabling: Smart adjustments: Fine-tuning your training plan based on detailed data rather than just feeling. Understanding your limits: Accurately identifying your fitness levels and individual thresholds for optimal progression. Efficiency: Targeting the right zones for specific workouts maximizes the benefits for your endurance training goals. Sustainable training: Helps you balance intensity and recovery to achieve long-term progress without burning out or risking injuries

The customer support provided by Frontier X2 is truly exceptional. They were incredibly responsive to a technical issue I was experiencing and replaced the device .They handled it with professionalism and efficiency. Highest recommendation.

After my device totally froze, would not startup and would not charge, FF arranged a video chat during which they led me through a series of steps to reset the device. After that it is now charging. I thought it was dead!

Received my Frontier X2 last week, got a chance to test it in four different areas that are of interest to me: Running, rowing, sleeping and breathwork/meditation. Impressed with the wealth & depth of data it provides and the clean representation of it. Besides the app, appreciate having a web dashboard as well for greater visibility into the graphs. Certainly takes heart rate monitoring to the next level! Battery life seems good, wore it for 12+ hrs straight and it was more than 50% at the end. It does stick out a bit so not sure I'd use it for sports that involve chest contact.

I'm not a super serious athlete but have always been a very active person with minimal health issues. Was surprised and discouraged to hear back in January that I have mitral valve prolapse with regurgitation at age 41. Have had cardiac symptoms on and off for years but I suppose I underreacted a little to these. I purchased the Fourth Frontier monitor so I could keep tabs on my fitness and heart strain while I exercised because that has been a regular part of my day, especially since I was diagnosed. My cardiologist was very vague and unhelpful about parameters for safe exercise so I decided to take matters into my own hands a bit. I love so many aspects of the app. It even maps my walks for me without me having to do anything. The heart strain parameter is huge for me. If it starts to tick up, I just lessen the intensity a bit. The ECGs do seem very high quality but I can't recognize much other than PVCs reliably at this point. It felt like a big expense at first but I can say after owning it for a few months, it is a great ally in my health and fitness. I try to listen to my body first but I now feel even more confident as I am receiving real-time feedback from this monitor.