A brief look at the Mio Alpha2 optical heart rate watch


Mio was on-hand at CES showing off both their recently announced devices from this past fall (Mio Fuse and Mio Velo), as well as demoing their just announced device: The Mio Alpha2.

The Mio Alpha2 builds upon the features found within the Mio Alpha (1).   For those looking for a brief history lesson, the original Mio Alpha was arguably the optical heart rate watch that started the whole optical HR trend within sports.  The original Alpha was launched on Kickstarter now over 2.5 years ago (crazy how time has passed?!?).  At the time it was the first sport device to measure optically on the market, whereas prior to that the technology was really only for use in medical settings.  Now of course everyone is doing something in optical HR recognition.


Since then the company released the product and went onto release the Mio Link, as well as then license out their sensor (using technology from Philips) into other devices including the TomTom Cardio series, and the Adidas Smartrun GPS watch and Adidas Fit Smart unit.  When I look at optical HR watches, it’s both Mio and Valencell (whose technology is used in the Scosche Rhythm+  and others) that really lead the way in terms of actually being accurate for sport use.


Now with the original Mio Alpha it was basically just a heart rate sensor that had a display that could show essentially your HR, time, calories, and HR zone.  It would broadcast that heart rate signal over Bluetooth Smart, though they briefly offered an ANT+ variant on Kickstarter only.  With the Bluetooth Smart version other phone apps as well as devices (now only recently available) could connect to it to get your HR, just like any other Bluetooth Smart HR strap.


Now we fast forward to the Mio Alpha2.  That extends the Alpha1 with the following functionality:

– Adds workout storage mode
– Adds ability to sync completed workout to your phone
– Adds pace, speed, and distance using an internal accelerometer
– Adds backlight
– Adds timers including countdown, repeat and chrono

Essentially what you are seeing here is the workout functions found on the Mio Fuse arriving within the Mio Alpha2.  What you don’t however see is the dual-ANT+/Bluetooth Smart functionality found on both the Mio Fuse and Mio Link.  That’s still lacking, just as it was on the Mio Alpha1.  Nor do you see the 24×7 activity tracking (steps/distance) mode found on the Mio Fuse.

Speaking of other Mio products including the Mio Link, here’s how it compares to the Mio Link size-wise:


As you’ll notice it’s about double the width of the Mio Link, this is obviously to accommodate the display that the Mio Link lacks.  From a size perspective in many ways I’d say that if you already have a watch capable of receiving the Bluetooth Smart HR transmission, then it’s silly to go with the Mio Alpha2 over the Mio Link.  Since obviously your other watch can display that data just fine as well as record it.


If however you’re just looking to display the HR data and have that data be accurate (compared to less accurate products from others on the market), then the Mio Alpah2 makes more sense.

Now as noted up above you do get both the lap functionality as well as the distance/pace functionality within the Alpha2.

IMG_3825 IMG_3826

And of course this is all tied into the workout modes that now actually save the data (the Alpha1 didn’t make that data savable).  So afterwards you’ll just use the Mio Go app to download the data (iOS/Android).  You can see my Mio Fuse In-Depth review to look at how the workout data looks there, as it’s identical within the Mio Alpha2.


Once that data is saved to the Mio Go app, you’ll soon be able to sync it to their online cloud service as well as export it out using the common file formats including .FIT and .CSV – both of which are coming soon.  Additionally you’ll be able to sync it out to a few other 3rd party apps they’re working with.

This is notable because it’s something neither the Fitbit Charge or Fitbit Surge supports today.  Even with their Premium Fitbit service you can’t get that GPS/HR data to other services.  There is one semi-geek-intensive tool to get the data out, but it’s in a raw format that you need to tweak a bit to display.  Hardly ideal or usable for 95+% of people out there.

While Fitbit has talked about possible upcoming Strava support a little bit in some interviews, they were still holding the line last week that they felt their own service was good enough, when I talked with them at CES.

Still, at $50 cheaper than the Alpha2 at $199, the Fitbit Charge HR is definitely something many are considering – especially since it does day to day step and sleep tracking whereas the Alpha2 does not.  I’ll be working on a review shortly there, whereas my Fitbit Surge GPS In-Depth Review will be next up to release early next week.


I don’t suspect I’ll do a Mio Alpha2 In-Depth Review, instead I’ll be focusing on getting my next Mio product review out for the Mio Velo, which is the combination of Mio Link and ANT+ to Bluetooth Smart bridging.  Further, given that I’ve covered the accelerometer related features found in the Alpha2 within my Mio Fuse review, as well as covered the core capabilities display-wise in that review also.  Thus really only leaving the lap timer related functions that are unique to the Alpha2.

Still, for any folks that have questions on the Alpha2, feel free to drop them below and I’d be happy to try and track them down.  Thanks for reading!

Welcome to CES 2015 posts! Don’t forget to check out all my CES 2015 coverage, as well as a slew of updates that were only seen on Twitter.  It was a crazy busy week!


Hopefully, you found this post useful. The website is really a labor of love, so please consider becoming a DC RAINMAKER Supporter. This gets you an ad-free experience, and access to our (mostly) bi-monthly behind-the-scenes video series of “Shed Talkin’”.

Support DCRainMaker - Shop on Amazon

Otherwise, perhaps consider using the below link if shopping on Amazon. As an Amazon Associate, I earn from qualifying purchases. It doesn’t cost you anything extra, but your purchases help support this website a lot. It could simply be buying toilet paper, or this pizza oven we use and love.

Post a Comment

Your email address will not be published. Required fields are marked.
If you would like a profile picture, simply register at Gravatar, which works here on DCR and across the web.

Click here to Subscribe without commenting

Add a picture



  1. Any possibility of any of these Mios giving HR in the pool?

    • morey

      The Mio Link works fine in the pool. I would presume that the Mio Alpha does as well, as it’s spec’ed to.

      Keeping in mind that Bluetooth or ANT+ won’t travel very far under the water. So, the Link would need to be positioned within a couple inches of your watch. Or, the Mio Alpha would record HR in the pool as well, but I don’t think it counts laps like my Ambit2 does.

    • Yup, Morey hit it on the head perfectly.

  2. kyle

    I love my Mio Link. I do have to wear on the same arm as my watch because of the signal issues with ANT+.
    Ray is there any truth to ANT+ not being able to travel through the body?

    • Yes and no. The Link has a less optimal antenna design which impacts the ANT+ side slightly more than the BLE side. This causes the case you’re seeing where you have to wear it on the same arm.

    • Greg

      I find ble to be soo much better, it’s a shame garmin won’t get in on it. The mio link with ble easily works across wrists with my Sony smartwatch, while it never did with my garmin 320. Plus most new phones can see ble. Seems shortsighted this mio does not do both or any sending… They could price it a little higher to do all of the stuff of the other items. I like lots of fields and two screens would be nice

    • This isn’t an ANT+ or BLE issue, this is just a poor antenna design issue. Generally speaking you actually get further range on most ANT+ devices than BLE ones.

  3. Dean

    Fitbit are indicating HR and GPS data access in their next API update, not sure when this will arrive but was announced a little while ago. It would be great to see it work both directions – this would make a really flexible solution.

  4. Myria

    Are any of the opticals going to be able to measure/transmit true HRV, or is the lack inherent in the smoothing algorithms they have to use to get a usable signal to noise ratio?

  5. Jeff

    Hey, Ray. I only mention this because you seem to care (and fix the typos) — “it’s both Mio and Valencell (who’s technology” -> whose technology.

    And great blog! Love your stuff.

  6. maarten

    Can you swim with it? Is that worth testing? I would be very interested in that.

  7. Trent

    I was hoping for features to compete with the fitbit surge & Basis Peak…. instead I’m left a little underwhelmed. Heres hoping they continue licencing their HR tech to other companies

  8. Rodrigo Valle Teixeira

    I wonder if this may enable a closer approach to actual “heart rate while swimming”.
    Given the HR data is stored in the Mio Alpha 2, if I take it along a Garmin Swim, (or a 920XT on OW) is there an easy way to merge the info from the 2 devices, and have HR on the actual workout data (distance, stroke, etc)


    • Anders Majland

      “Fit File Repair Too” (link to fitfilerepairtool.info) can easily merge logs from different devices

      I use a Garmin Vivofit to log HR from my Mio Link and it shows fine on garmin connect as type “other”. As soon as i change the the activity type to swimming it used to loose the HR – Well i just tried again and it is now fixed . Tada !!! – At least some of the newest entries also shows vivofit swimming activities with HR, but not for all the old ones …

      I mostly use endomondo and here is one of last years outdoor swims:
      link to endomondo.com

      and the two seperate entries on Garmin Connect from the 910xt and vivofit
      link to connect.garmin.com
      link to connect.garmin.com

      I’ve just exported the two original files, combined them with Fit File Repair Tool and uploaded them again.
      link to connect.garmin.com
      Now the HR is showing as well.

      Fit file repair tool is easy to use but i can’t see any technical reason why a garmin watch (910/920 or newer) should not record the ant+ heartreate from a mio link in swim mode – it does it fine when on the trainer in cycling mode)

      Until i can get a single device that works in swimming i’ll get by with carrying all 3 devices. Actually last sunday i was also wearing the Amiigo that just showed up after a 2 year wait since the kickstater funding.

  9. Mirko

    I got a Mio Fuse last week, I was pretty excited with this kind of technology so that I could drop the chest strap. It turns out though that it works horribly for rowing, which is one of my main cardio activities during the off season, and according to other folks on the web I am not alone in having this kind of issues.
    Any suggestion Ray? It would make sense for me to return it while I can, though I can still use it for runs (and hopefully it is OK for cycling as well)

    • Have you tried moving it to different places? i.e. the inside of the wrist?

    • BillM

      I would try to return it if I were you. I had a link, wore beside watch due to signal issues and eventually switched to a scosche rhythm+ which never drops signal when on other wrist and presumably will work fine in rowing too. I’ve posted this before but I still can’t understand why mio continue with what is obviously a flawed design re antenna on an otherwise brilliant device. They have designed their user guides around this issue- asking the user to wear beside wrist. However on the Go App somewhere along route to downloading the app there is an image of someone wearing the link without the watch being on same wrist so I think they originally envisaged wearing on opposite wrist, just as most users would expect to be doing.

    • Mirko

      Yep, tried everything: inner/outer position, closer to the wrist/higher up on the forearm, tighter/looser … everything to no avail unfortunately. Plus my Polar H7, to which I had to revert, started misbehaving as well (app says it is connected but the reading is just “–“). This after just one year since I purchased it, though at the time I had to get it replaced straightaway since the first unit did not work at all. Sorry guys for all this frustration but it’s too bad that we cannot apparently sort out heart rate monitoring in a convenient way in 2015. Maybe I should just get a Garmin watch+strap bundle and cross my fingers.

    • Mirko

      seems like this guy’s experience is pretty similar to mine: same technology & same activity
      link to jwshale.com

    • Christian

      I’ve had the same results with every Mio device available as well as the Fitbit Surge while playing tennis. Too much arm motion makes these devices worthless.

    • You might want to consider an optical device that’s situated further away from your wrist (like the Scosche), as that minimizes some of the impact there.

  10. Alex

    I was hoping they would integrate some bi-directionnal bluetooth features in alpha2, meaning getting pace/distance from the smartphone (like magellan echo ) instead of it we get an internal accelerometer which I dont find very useful, since it doesnt even work as a all-day activity monitor.

    • Brian

      I was hoping for this as well and could’ve sworn that bi-directional bluetooth was an advertised feature.

    • tom dolan

      they previously claimed – past tense – bi-directional data exchange on their website – seems to be harder to find now. I tested the distance/pace against strava on iphone on a 14 mile run and it was 1.2 miles and 40 seconds off respectively – so I’ll be returning mine :-(

  11. Annette

    I did not see anything discussed in this post or maybe just missed it: with the Alpha2- is it possible to program complex workouts and sync them onto your watch? And if I understand correctly- no GPS unless connected to smartphone? What I would give to free myself from the chest strap!

  12. any idea if garmin will feature something similar on their watches in the near future?

    that would be cool!


  13. Steve

    I’m wondering about the algorithms used in calculating pulse from an opticaI based sensor. I have been recently using the Jabra Sport Pulse Wireless headphones with optical heart rate tracking and my iPhone 5S – it seemed to work really well, but I felt like it was reading a little high. So I did a run with both the Sport Pulse and a Polar H7 at the same time.
    They were both pretty much the same but the Jabra did read consistently slightly higher – my max pulse on the run was 163 on the H7 and 168 on the Jabra… I’m curious as to why they would be different.

  14. Patrick

    What are you referring to when you say “If however you’re just looking to display the HR data and have that data be accurate (compared to less accurate products from others on the market)“. Do you mean there are other optical HR sensors which are less accurate – and which ones?

  15. MacroPhotoFly

    Really very annoying no ANT+ on this watch. Do not understand why given size and cost. Deperate for a watch with time on it that can free me of my chest strap and works equally well at providing HR to my phone when running and my garmin 800 when cycling

  16. DLJ

    What’s the latest on Mio/Magellan’s ideas for straight up cycling computers like the Cyclo 505.
    It seems that they have gone a little quiet on those – no new firmware for instance despite being promised for a while.

    Ray, do you think they are moving away from the competition with Garmin Edge units in favour of this sort of wearable tech?

  17. Madan Raj

    You mentioned about getting raw data out of MIO alpha using a semi-geek-tool. Can you please elaborate on this. I am interested to get the raw data from MIO into my own app for processing. Any help or suggestion would be appreciated.

    Thanks & Regards,

    • When I mentioned the word “raw”, I was referring in that paragraph to the Fitbit products and tools.

      With the Mio, it’s a standard Bluteooth Smart HR strap device, so you can easily use any app (such as the Wahoo Fitness app) to record the data and then export to CSV.

  18. Millardski

    I am considering a Mio Alpha 2, but am concerned at such comments as “Too much arm motion makes these devices worthless”. Do you think use during Mountain Biking and Skiing would be unlikely to record accurately, or do you think these are lower impact on the arm/wrist than Tennis?

    • I don’t think that’s accurate at all. It’s not so much motion that’s challenging, it’s impact motion – such as tennis, or in some cases, weight lifting. Mountain biking and skiing are largely perfectly fine.

  19. Lluís Soler

    I just got a Mio Alpha 2 to use during my workouts instead of the Fitbit Charge HR (a good 23/7 activity tracker).

    Since Mio GO app for Android doesn’t show the HR graph, I’d like to know if there is a way to sync stored workouts in the device to some other app (not just sync the Alpha to my phone while exercising, but being able to sync the stored data after the workout), so I can see the HR graph.

    Thanks in advance.

    • John A. Johnson

      Fortunately an update to the Android version of Mio Go finally displays a HR graph. Now if only Mio would provide a way to export stored data from the app, I would be satisfied with the software.

  20. kiwiburner

    Mio Alpha 2 or Basis Peak? I have particular interest in sleep monitoring..

  21. hrishi

    I wanted to clarify:
    While swimming with Mio Alpha 2 (as with Fuse), one need not wear another watch as HR receiver, right? It will monitor and record HR data that I can later sync with Mio Go, right?

    Also, I undertand Mio discourages pressing buttons underwater. But for counting laps, if I take the device out of water (for 1-2 sec), press the lap button, and submerge it again, you think there would be any issues?


    • 1) Correct
      2) I wouldn’t think so – but then again, I don’t really think there’s any true issue with pressing buttons underwater either.

    • Voldemar

      I have recorded 10 laps to the Mio Alpha 2 while swimming. But after syncing to Mio Go app, it show only best lap time.
      Any chance to check all lap times?

    • David Rousseau

      Same here, we’re now March 2018 and the firmware hasn’t fixed this issue. We can have the fastest lap, but we cannot view results per laps after the training. So you don’t see how long were each lap, what was your HR during those, etc. Frustrating quite honnestly. I’m quite surprise… this is like a most for people training…

    • Just speaking realistically, I wouldn’t hold ones breath.

      The company exited the hardware business last year to focus on PAI (a software based calorie algorithm).

  22. Andrea Gemmell

    I just bought the Mio Alpha 2 – currently trying to set up the Mio Go. I have downloaded Mio Go to both my ipad and also my Samsung Galaxy S5 but noticed the heart rate zones are calculated differently on each device. Ipad zones 1-5 range from 0% to 100% but the Samsung Galaxy has 120% being the upper limit of zone 5 ! I’m amazed there would be any difference ! Surely the app data should be consistent across all devices ???

  23. kamsuj

    Hi, does Mio Alpha 2 have new better heart rate sensor (more accurate) than Mio Alpha (1), or it is exactly the same only difference is software and accelerate sensor?

    Thanks for replay,

  24. Lluís Soler

    Any news about exporting data from Mio Go app?

  25. Josh

    Hey DCR,

    Long time reader here…

    Can you tell me if you can use the alpha 2 like the suunto ambit 3, where you can automatically sync your alpha 2 workouts to movescount? I know you mentioned the open nature of the data, so I was hopeful that this would allow for auto-upload to movescount. I have an ambit and fuse now for my workouts, and there are a couple issues I have with that… 1) it’s a bit of a cumbersome pain. Both devices are huge, though together they do the trick. 2) you need to sync the data with that proprietary wire at your computer (or carry your phone on runs). I track all of my workouts through Movescount, which requires the tethered wire for my ambit… Looking to lose the wire, and I have a feeling the only way of doing that would be to buy the ambit 3 and keep using my fuse as the hrm.

    Am I right? Thanks.

    • No, only Suunto devices can get to Movescount unfortunately. Sorry!

    • Josh

      Ugh… Okay, is there a way of sending the Mio data to another service that flows into Movescount? I’m pretty sure their app tethers through Map My Run… Could I somehow back-end it and get it to force to Movescount? I picked up an Alpha 2, and I’m struggling to understand what’s good about it, since the Mio apps are so lousy. That, and I’m way too invested in Movescount with all my previous data… :)

    • I’m not seeing any obvious way, since the limiter here is Movescount (outside of Strava sync, it’s a walled garden). If you use something like Tapiriik to get out of MapmyRun (or anyone else really) – you’re still stuck with no way to get it into Movescount: link to tapiriik.com

    • Josh

      Back to the drawing board… Looks like I’ll have to get a Ambit3 Peak, and use the Fuse I’ve already got. So many devices… Any word on Suunto licensing Mio’s tech? That would be something I would be into :)


  26. Michael

    Hello Sir, from your experience, what do you think is the most accurate heart rate watch (without chest strap)? GPS and other functions are not important for me, just strictly HR accuracy. Thank you for your time Sir.

  27. jamey Ward

    Hi Ray,
    I’m curious. I have a Mio Fuse and was talking to MioGlobal online about possibly moving to the Alpha2 for soccer match use. And they were nice enough to advise me to hold off vs making another purchase because they may have some interesting stuff to announce at CES 2016.

    Do you have any tidbits of what they may add to the Alpha 2 or possibly an “Alpha 3” with more features and what they may or may not be??? I’ve loved Mio Products so far! Thanks for any insight.

  28. Marat

    I wonder if Mio or any other device records continous heart beats – i.e. not just the average rate but the actual time of every heartbeat. If it can export the data and can by synched with Galaxy 5 it would be adouble bonus ;)

  29. Ken W

    I have had about a dozen timex ironman watches over the past 35 years… Replacing them every few years. Lately it’s been due to a degrading band, which is irreplaceable. Getting bored of that. What I use most is the stopwatch/chronograph/lap counter. It seems watches are now starting to have optical HRM. I like that, since I usually determine HR manually, and have never been interested in a chest strap… I am also not interested in storing data. Just want to glance down, see my HR, see my lap splits, and keep going. Is the alpha2 the best option for me?

  30. I’m a trail runner and bought the MIO Alpha 2 mainly for heart rate tracking as that’s how I train (by heart rate) and the distance and pace features were bonuses for me….but….I find that the accelerometer used for tracking distance and pace isn’t very accurate at all when I compare to my Garmin 305. Can you speak about the accuracy of these features?

  31. Neill

    I decided on the Alpha 2 over the Garmin Vivosmart HR due to the multiple accuracy reports of the Mio. I’ve owned it a week now, and so far been happy with it. The firmware update is a clugey process, but after a few tries I was able to get it to take successfully (Android 5 on LG G3).

    My findings so far:
    – fit: it is OK. The face of the watch I think is probably on part with a decent sized watch. The band is soft and not uncomfortable. The first 2 days I thought it was going to bother me, but now it is fine. I don’t wear it really tight until I turn on a workout (HR mode).

    – step counting appears conservative…Mio states this is intentional as their belief is most other step counters are aggressive and count too many…I tested it vs LG counter and a Fitbit Charge…it was closer to the LG counter on my phone. I cannot find a way to adjust my step stride

    – works well for activities where your arms are not extended over your head. Specifically during workouts I noticed it seems to get lost if I’m lifting dumbells over my head, but for bikes, etc., it seems to track well. My thoughts are anything with a lot of arm movement or with arms extended over your head, ie, activities that might make it harder for the blood to flow all the way to the wrist are problematic for tracking HR on the wrist. I have not compared HR to anything other then bikes and other machines that have hand sensors…so far on par. I will, eventually, put on my Polar FT7 and compare.

    – tennis appears a no-go. I tried to track a match last night, and during warmups I noticed it was getting lost and not tracking HR. I tried switching it around to the underneath side of my arm and tightening, but it didn’t seem to help. I will try again tomorrow. Unfortunately I took it off, so cannot report on how it did step counting…will see in a match tomorrow.

    Overall, I’m happy with it. Will update as I get more time with it.

    • Neill

      UPDATE: well last night it worked great playing tennis!

      I kept the sensors on the top of my wrist, and put it on pretty tight.
      2+ hours and looking at the graph in Mio Go, really never lost my HR. Tracked distance and calories burned nicely. (2.56 miles, 150 avg HR, 2230 calories, most of time in Zone 4)

  32. After a year’s use, the Mio Fuse continues to work very well, in general.

    I have experienced a couple of problems, neither of which has proved to be insurmountable.

    One is that if I exercise for more than an hour, I have a hard time turning off the heart rate monitor. It does not want to progress from Pause to End. Instead, it switches back to Go, and then I will have to try to stop it again. Sometimes it takes numerous trials to get the HR monitor to stop. The problem seems to occur only for relatively long workouts. For anything less than an hour there is generally no problem turning off the monitor.

    The other problem occurred one day while playing basketball (my primary use of the Fuse). Another player brushed past me and I saw the Fuse drop to the floor. I thought that the band had come undone, but then I discovered that the band had torn apart. Before ordering a new Fuse I figured I might as well try to super-glue it back together, and, voilà–good as new! It has held up fine for several months with no evidence of coming apart. Last week I took it to Mexico and wore it while snorkeling and in the heat of Mayan ruins. It is really sturdy.

  33. tavis

    Hello. I recently purchased the Mio Alpha2. I was under the impression that I could pair it with a Scosche Rhythm+ when running in cold weather with the Alpha2 on the outside of my long sleeve shirt (doesn’t help to have a heart rate monitor under my clothes where I can’t see it).

    Is this set up possible? If not, is there a device out there with a wrist-based heart rate that can also be paired with the Rhythm+ for use when the device is not in direct contact with my skin.

    Thanks for any advice and recommendations.