Mio Alpha Review: One Giant Leap For Heart Rate Monitors

Chest-strap heart rate monitors suck. I mean, yeah, they work okay, but they give you that tight-chest-"am-I-having-a-heart-attack?" feeling. That's why the Mio Alpha, a wristwatch that accurately measures your heart rate, is such a big deal. But that doesn't mean it's perfect.

What Is It?

It's a watch that measures your heart rate.

Who's It For?

Runners and cyclists, mostly, but really anybody who wants heart rate data during their workouts, whatever they be.


On the front, it's a plasticy-looking digital watch with a rather thick wristband. There are only two buttons (one on each side). Turning it over is where it gets special. There are two green LEDs that shine into your skin, and an electro-optical cell that senses the tiny changes in the color of your skin, indicating the flow of your blood and thus your heart rate. It's basically the same tech as medical oximeters that are used in hospitals, but miniaturized and wearable.

Using It

Put it on your wrist a bit tighter than you would a normal watch. Hold down the button on the right and give it about 10 seconds for it to lock onto your heart rate. Hit that button again and it starts a stopwatch. It will alert you if you're over or under your target heart rate zone (which you set before hand), by beeping angrily and flashing a colored LED. When done, you can view a few stats from your last workout, such as average heart rate, and how much time you spent in your "zone." It has a Bluetooth 4.0 Smart radio, so it can send your heart rate data in realtime to your favorite running/workout apps (RunKeeper, Endomondo, Nike+, etc.) on newer smartphones like the iPhone 4S, 5, and certain Android phones (maybe). An ANT+ version is also available. Update: Sounds like the ANT+ version was just a prototype. No announcements about that version being available have been made.

Mio Alpha Review: One Giant Leap For Heart Rate Monitors

The Best Part

Convenience. This is actually something that people would use. Chest straps are a royal pain that involve removing clothing and require you to pair with other devices. This is a one-stop shop. You can pair it with your phone, but you don't need to.

Tragic Flaw

It still feels like a prototype. There's a lot of basic functionality missing as far as watches go. For example, there is no lap/split time in the stopwatch, there is no countdown timer, and there's no alarm. A lot of us can't run until we get home from work in the evening. If that's you, good luck seeing it, because there's no light for the display. These are boxes that a $20 Casio checks.

This Is Weird...

Bluetooth 4.0 Smart is a relatively new protocol, and it's cool because it way easier on the battery for your phone and for your watch. It enabled the Alpha to work extremely well with various workout apps on the iPhone 5 during testing. However it claims that it will work with certain Android phones/applications. Having tested it with 5 different applications on 5 different (very new) Android phones, I could not get a single one of them to work. The company could not provide me with the names of a phone/app combination that would work. So, as of this writing, as far as I can tell, it does not yet work with Android. But, it can. Nordic made a little app for the Galaxy S III called nRF Utility basically to demonstrate the Bluetooth Low Energy technology, and it worked perfectly with the Alpha. So, it can work, it's just that app developers need to adapt their apps to recognize BLE (a.k.a. Bluetooth 4.0 Smart) devices. Or Google needs to build that directly into Android. It's a serious knock for Android users, though it's not really the Alpha's fault.

Mio Alpha Review: One Giant Leap For Heart Rate Monitors

Test Notes

  • The Alpha charges via USB. You get about ten hours of monitoring time per charge, or many weeks of just plain watch time. Very solid.
  • The Alpha is generally very accurate. Compared to the chest strap I tested it against, it was almost always within a few BPM. It is, however, subject to occasional anomalies, so you may see some spikes and dips in your workout summary (if you're using an app). Also, the Alpha would lose my heart rate once on almost every run, and you pretty much have to stop running and stand still for it to reconnect, which is really annoying. If you're in training, you'll probably just say "screw it" and turn the thing off.
  • Embarrassing personal anecdote: I worried that the reason the Alpha was sometimes losing my heart rate was because, well, my wrists are kinda hairy. "Maybe this wouldn't be a problem for a less sasquatch-ian person," I fretted. So, out of a desire to be fair, I shaved a small patch on my wrist (where the sensor goes). It didn't seem to make any difference. And now I have a weird bald spot.
  • Mio says "you can wear your Alpha while swimming." Which is true, in that it will not melt. It will not, however, work worth a damn. I wore the Alpha on three different swims in a warm pool, and the results were unusable at best. It was often off by more than 40 BPM. You don't need to worry about it in the shower, though.

Should You Buy It?

It's a tough call. It's easily the best heart rate monitor watch yet, but part of that is because the others have been so bad. The Alpha mostly works really well, most of the time. If that's good enough for you, and/or if you hate your chest strap that much, and/or don't mind dropping $200 on a new heart rate monitor, then go for it, you early adopter, you! For most others, this is an item with tremendous potential, but we can't help but think that version 2.0 (assuming they make one) will be much better. [Mio]

Mio Alpha Specs

• Radio: Bluetooth 4.0 or ANT+ versions
• HR Method: Electro-optical sensor
• Backlight: No
• Water-resistant: Yes
• Color: Gray or gray with white trim
• Price: $200
Giz Rank: 2.5 stars