in Gear and Reviews

Review: Mio Link Heart Rate Wristband

If you hate the chest strap that came with your running watch, but love the idea of tracking your heart rate during your runs, then take a look at the Mio Link optical heart rate monitor.

Mio Link HRMWhen I first heard about the Mio heart rate monitors (HRM), I was very sceptical. Early wrist worn, optical HRM’s were prone to dropouts during workouts and didn’t provide the same accuracy as the chest-strap monitors.

How it works

Mio promises that their Continuous Technology will accurately read your heart rate at speeds up to 15mph. The key is noise-reduction technology that filters out the disturbances caused by motion. Reviews suggested that the Mio lived up to the marketing hype, so I picked one up.

All of Mio’s HRMs use optical technology consisting of two green LEDs and an optical sensor. It’s literally a camera mounted on your wrist that images your skin and watches for the blood pulsing through your tissues to measure your heart rate.

The Mio Link consists of a small sensor that tucks into a silicone wrist strap. It’s smaller than a watch, and fits nicely on the wrist thanks to the stretch in the band and a nicely designed clasp system.

Fully integrated with the fitness watch you already have

With ANT+ and Bluetooth Smart (4.0) technology, the Mio Link is able to connect to your smartphone (Mio offers apps for iOS and Android) or to your existing GPS watch. There’s a complete list of compatible devices on the Mio website, but for Garmin owners, if you have a Forerunner watch that supports a chest-strap HRM, you are good to go.

I use a Garmin Forerunner 620, and the Mio Link connects up instantly and replaces the chest strap HRM. Heart rate data is shown in real-time on the watch, and shows up in the data files. It’s no different than wearing the Garmin chest strap, except that you don’t have to wear the chest strap.

My experience

Personally, I wear my Mio Link above my Garmin Forerunner 620, a little further up my forearm (see image below). I could wear it on the opposite arm, but during walks, Mio says that it’s possible that the ANT+ signal could be lost as the technology doesn’t penetrate the body all that well.


Accurate heart rate data, with no drop outs.

That’s not a Mio issue, but a limitation of ANT+ in general. Wearing the Link on the same arm as my Garmin means I don’t have to worry about any dropouts. It’s so comfortable and light that I don’t notice it at all.

I’ve run about a dozen times with the Mio Link and it’s been rock-solid and perfect on every run. No dropouts and the heart rate data looks accurate from start to finish, no matter what pace I ran at. The screenshot from my Garmin log backs up that claim (see image right).

The only issue I ran into was when Ginny joined me for her run one night and we didn’t get the pairing right between our two Garmins and two Mio Links. My Link ended up connecting with both my Garmin 620 and her Garmin 210.

A Twitter exchange with Mio cleared up how the pairing process works and we haven’t had any issues since, even while running on side-by-side treadmills. We just link up our Garmin and the Mio at separate times to make sure the watch detects the proper HRM.

Additional details

The Link is a really simple device. It features just a single button to turn it off and on and a five-colour LED light on the wrist strap that tells you at a glance which heart rate zone you are in. Those zones are customizable via the Mio app on your smartphone. It’s water resistant to 30m and sweat is obviously not a problem.

Mio Link HRMThere’s no onboard memory or storage on the Link – it tracks heart rate and sends it to the app via Bluetooth Smart, your fitness watch via ANT+, or both if that’s what you want to do.

For marathoners and ultra-marathoners, the 7-10 hours of battery life for continuous heart rate monitoring means your watch will likely give up before the Mio does. Charging is via USB using a custom charger that the Link magnetically snaps onto.

You can choose one of two different strap sizes. I opted for the regular sized band, but I think I could have gotten away with the small one as well. If I wear it on my wrist where I would normally wear a watch, I’m near the last notches on the band. Mio provides a sizing band you can print out if you aren’t sure which one to get.

The verdict

If you hate your chest strap HRM, the Mio Link provides a drop-in replacement that will likely work with your existing fitness watch. You’ll get accurate heart rate data, without dropouts, even during your hardest runs.

At under $100CDN, it’s an affordable way to add the value of heart rate monitoring to your training.

Learn more about the Mio Link and the full range of Mio heart rate monitors at their website.

Disclosure: as with most of the things I review, I purchased the Mio Link for myself at MEC ($95+tax, shipping is free). In fact, I liked it so much that I bought a second Link for my wife to use during her runs. Freedom from chest straps!