
At a Glance: Quick Ratings
Heart Rate Functions
Fitness / Sport Features
Ease of Use
Battery Life
Where To Get It
A Deep Dive Into Mio Alpha 2
Thank you for visiting our review of the Mio Alpha 2 sports watch featuring Mio’s patented strapless heart rate monitor sensor.
Accurate heart rate feedback taken directly from the wrist and 90-95% accurate speed & distance feedback from internal accelerometers (no GPS). Exceptional battery life > 3 months in watch mode, up to 20 hours in exercise mode. The Mio Alpha 2 has been reviewed by Tristan Haskins
In Feb 2021 Mio released the Mio Slice. The Slice is the world’s first activity tracker to include PAI, that’s Personal Activity Intelligence.
Rather than “just” count steps, the Mio Slice wants to see elevated heart rate at regular periods throughout the day. As with all Mio’s products is features WRIST BASED heart rate.
If you are looking for a motivational, innovative, stylish, water resistant fitness tracker then you may want to consider the world’s first PAI powered fitness band – the Mio Slice.

Who Is It For?
Video Review
The Mio Alpha2 is for the exerciser who predominantly runs. They want to train within a heart rate zone, or multiple HR zones. They also want feedback on performance, time, distance and pace. The Mio Alpha 2 is NOT a GPS sports watch it uses an internal 3 axis accelerometer to accurately provide feedback (live and post session) on how far, how fast (speed and pace), heart rate (with BPM and a coloured LED) and calories burnt.
Main Features and Functions
Like the Fuse we tested yesterday the Alpha 2 impressed us most with it’s strapless HR sensors and the accuracy of the internal accelerometers. They have proven to be VERY ACCURATE with close to GPS accuracy when walking and jogging. The Mio Fuse provides both SPEED (eg. MPH) and PACE (minutes per mile).
The Alpha 2 is supported by the Mio Go APP which we found to be very easy to use with excellent post session feedback and the ability to set the key features of the watch including SINGLE or 5-Zone heart rate training.
- STRAPLESS, off the wrist, EKG accurate heart rate monitoring
- Highly accurate internal accelerometer providing feedback on speed, distance and pace
- Easy to use straight from the box
- 1 or 5 heart rate zones (user configurable via Mio Go App)
- 20 hours of continuous heart rate monitoring… Not confirmed yet, but this probably equates to 2 or 3 weeks of daily use training for an hour per day.
Detailed Features
Speed & Distance with no GPS
I must speak about the accelerometer for a moment… as I was a little bit dubious about a NON-GPS speed and distance watch. I am aware that certain Garmin and TomTom watches have internal devices to track speed and distance when GPS is lost, but they units I have used in the past that rely solely on accelerometers have been OK at best.. inaccurate at worst. NOT SO HERE.
Accelerometer Accuracy
The Mio Alpha 2 was used by me for 3 x short runs. I did 1 mile on the treadmill and the Alpha2 said 0.98 miles. This impressed me considerably. Would it work as well outside? I then ran 1 mile on my local promenade with my Polar V800 for GPS comparison. 1 mile later on the v800 > > 0.97 miles recorded on the Alpha 2. Finally a 2 mile loop. Polar V800 stated 2.00 miles, the Mio 1.95 miles. For the recreational runner who wants a good indication of distance ran (possibly with a marginal error in accuracy) with the HUGE convenience of NOT having to wear a chest strap for heart rate monitoring, the Alpha 2 may be perfect.
The convenience of heart rate controlled running without a chest strap make the Alpha 2 perfect for the fitness enthusiast maybe someone who like to do the 5K Park Run or Race For Life. It’s a great watch for those wanted freedom from the HRM strap with calories, distance, and speed feedback.

PAI on the Alpha 2
The Mio Alpha 2 cannot display your PAI score, but it is available via the Mio PAI 1 app following upload of training sessions. PAI is a more effective way of measuring daily activity by analysing heart rate throughout the day, not JUST step counting. More details on PAI and how it works can be found here.

Top Alternatives
Next Model UP

There isn’t really a model up from the Alpha 2. This is the top of their range for Heart Rate Monitor sports watches.
If you are looking for ACTIVITY TRACKING and the ability to transmit your heart rate data to either an ANT+ device (like a Garmin Edge or Forerunner) or Bluetooth 4 smartphone APP like Strava or RunKeeper, then you may like to consider the FUSE.
Next Model DOWN

Similarly there isn’t really a model BELOW the Alpha 2. If you’re certain you want STRAPLESS heart rate monitoring and you want the unit to look like a regular time of day watch… then stick with the Alpha 2. If you want to save a few £££’s, then you may also consider the original Mio Alpha watch.
Mio Comparison Table
If you are undecided which Mio product is best for you, we hope this comparison table courtesy of the MioGlobal website might help.
>>Want a heart rate monitor watch? Check out the Mio Link HR Watch, read it here!<<


Review Summary
The synchronization between the Alpha2 and your smartphone could be quicker, but that’s certainly not the slowest we have ever tested. Just like the FUSE we’d like it to have a DAILY ALARM. This could be set in the APP the same as you can do with something like the Garmin Vivosmart. As the Alpha already has an internal accelerometer, I was disappointed to see that it wasn’t being utilized as an ACTIVITY TRACKER. I’d like to see the Alpha do EVERYTHING that the Mio Fuse does … if we had a combination of ALL features from the Fuse, in a case like the Alpha with a display like the Alpha we would have a 4.5/5 product…
If you want to keep your training within a heart rate zone, without the need for a chest strap and you’re also interested in speed, pace, distance and calorie feedback (without extremely good but not GPS level accuracy) then the Mio Alpha 2 could be just what you’re looking for.