MIO Alpha 2 Review – Optical Heart Rate Monitor with Watch Display

IMG_3791MIO first came to more widespread prominence with their MIO Link optical wrist band. The Link is a great product for what it is intended; some people, however, also ‘needed’ a watch-like display and increased functionality. So the RECENT incarnation of the MIO Alpha, the MIO Alpha 2, came into being.

Why am I reviewing an early 2015 watch in the middle of 2015? Well, partly I’ve been busy and I hadn’t got hold of one until recently, but also the market has moved on and the initial reviews that lurk out there have been outpaced by developments as MIO partner with Garmin and as optical HR take-up is kicking off with much more to come in the near future from other vendors.

What is it in a nutshell?

MIO Alpha 2 Review
MIO Alpha 2 Review

It’s an optical Heart Rate Monitor (HRM) for the wrist. It will also broadcast heart rate data as a Bluetooth SMART (Bluetooth Low Energy BLE or BTLE) signal to an iOS- or Android-based app. It has a rudimentary, ‘retro’ display where you can see heart rate, duration and other such data as well as performing laps. Distance data comes from an accelerometer NOT GPS. Configuration is accomplished though the smartphone app MIO GO and that APP can also sync stored exercise data from the watch.

App v2.4.1 was used with firmware v1.01.

For a function-by-function view look at the manual: Mio_ALPHA_User_Guide


IMG_3793Optical HRMs vary in their accuracy. In my opinion MIO/Phillips has one of the best implementations of that technology and, indeed, they now partner with Garmin to provide that technology to the world’s largest sport watch manufacturer (Garmin). The claims of EKG level accuracy are here (https://www.mioglobal.com/docs/sfsu_mio_ohr_accuracy_study.pdf and see also http://www.mioglobal.com/docs/mio_optical_heart_rate_study.pdf) however I was somewhat sceptical of the breadth, depth and quality of that first study.

But then in my even less scientific study with the MIO Link I found a pretty good level of accuracy. Certainly a level of accuracy that I would be generally happy with.

I also thought I’d go for a bike ride with one and this is what came back to the app.

MIO GO Cycling With GPS
MIO GO Cycling With GPS

You can see towards the end there was a dropout and I did spot this whilst I was cycling relatively quickly. the rest of the ups and down in Zone 2 and Zone 3 are there or thereabouts right. Here is what Mr Garmin had to say on the matter and don’t worry about the zones being different that’s just because they are not set the same by me on the MIO ALPHA 2:

1k intervals 03-07-2015, Heart rate

Aesthetics and Form

Aesthetics are a personal thing. I’m probably ambivalent about the Alpha 2. I’d wear it. If you like it, buy one and ignore my aesthetic whims!

However what I would say; it is VERY comfortable.

The buttons are a little hard to press sometimes and don’t give as much feedback as would like. Certainly not a show stopper and certainly better than some others. The screen is easy to read, understand and navigate through its functions.

The App, Setting Up and Configuring

I found setting up the Alpha 2 more difficult than it needs to be and more difficult than with the MIO Link. For example pairing was difficult with a MIO Fuse already paired and two other Bluetooth applications open in the background (STRAVA and BIOFORCEHRV). Pairing to the MIO APP just didn’t work – once I restarted the smartphone it was fine.

For any Bluetooth SMART heart rate monitor you need to ensure that it will work with your desired app and your desired smartphone/device. For example I tend to use an old Samsung S3/iPAD 3 and the WAHOO FITNESS App – which I have to say requires a somewhat tortuous process in order to get pairing fully working (for any HRM by any manufacturer). It USUALLY does work by hook or by crook and so if I can get this to work then it bodes well for the likely more modern combinations you will be using. Several apps I would class as ‘not robust’ or require premium versions to enable all half-decent functionality. (A ‘usually works’ alternative to the excellent WAHOO app is POLAR BEAT).

A further problem with the app was that I could not get any data out of it (export). Normally I would have liked to have compared more directly the two heart rate tracks (above). That was not possible or at least not obvious to me how to do it.

Using It

Again here is the manual, I try to avoid glorifying them by reproducing the same content in different words: Mio_ALPHA_User_Guide.

I will dwell on the unusually good points and ‘other’ points:

Unusually Good

  • Optical HR on the wrist. Saves wearing a chest strap.
  • Very accurate HR for this kind of device. FWIW: near enough best-in-class.
  • Flashing light changes colour based on your HR zone
  • Water resistant. You can use it for swimming. Apparently you can’t  press buttons underwater.Exercise data is cached and syncing seems to work fairly well back to iOS and Android.

Consider this too

  • This is a Bluetooth-SMART-only device NOT ANT+.
  • Can take over 10 seconds to pick up your HR
  • NO GPS; distance NOT PACE comes from an accelerometer. (Pace/Speed MUST come from your phone’s GPS into the app you use)
  • Distances are lower than those obtained from GPS, this may also lower the calories-used calculation.
  • Buttons are fiddly to press – but impossible to press by accident.
  • Supports caching for syncing later but this sometimes did work with the MIO GO app. It only works with the MIO GO app.
  • Pairing is a little confusing – you must pair with the APP not the phone. It will not pair with the phone’s Bluetooth section (Android).
  • Pairing is not great if other (MIO) paired devices are present, it will sometimes not pair.
  • Battery life whilst exercising is stated as 8-10 hours; over 20 hours with HR monitoring on, longer as just a watch.
  • HR will record up to 220 bpm but I experienced discrepancies above approx. 166bpm with my MIO Link tests. With the Alpha in this review, the accuracy was good compared to the Garmin at mid- to low-HR levels (<165bpm for me)
  • The MIO GO app will not transfer your sessions to an internet service. It doesn’t have one. You’ll need to use a different app for that functionality.
  • Didn’t pick up GPS speed for me on an Android device whilst cycling. GPS was definitely turned on (despite what the image above shows).


This is a comfy, nice-enough looking sports watch. If you’re going to be using it for walking or jogging then you’ll be fine in terms of accuracy, you’ll be fine too using it in most gym classes.

If you look at other reviews, people either love it or quite dislike it.

More serious runners may experience inaccuracies the higher the HRs get. But for your long runs, you’ll be fine. The on-device metrics are very limited and if you are a serious runner they are inadequate.

The MIO GO app is perfectly fine as a configuration utility. However as a sports app it lacks oomph – for example lacking an online interface to transfer sports history between devices within the MIO environment. For me the app lacked decent speed data. Of course there are many alternatives you can use this product with. The point is you WILL most likely HAVE to use those other products/APPS. But having said that, I think that was MIO’s intention all along – they aim to make good hardware and then you use someone else’s flavour of the month APP. You and I might not like that but it IS a sensible strategy for a smaller company and has served them well so far.

In the end it’s a screen-glorified optical HRM for the wrist. But that’s OK. Good, in fact if that is what you want.

Would I recommend it? Probably not. But if you see all the features you want then go for it. It is good for what it is.

July 2015: It’s priced at GBP117. This is tempting but I still think overpriced. For a similar price you can get a vastly superior Polar M400 (review here) with the vastly superior Polar application and internet ‘ecosystem’ – albeit the Polar M400 has a chest strap. So the clincher is the optical HR and the aesthetics/wearability which many will like. And for a smart band/activity tracker the Microsoft BAND is superb but a little more expensive at present (July 2015) than the MIO Alpha 2.

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