Wahoo Fitness Dongle: The Sharpest Fitness Tool In Your Shed [Review]



Till January of this year, the Wahoo Key for iPhone ($80) dongle pwned fitness on the iPhone. Why? Because the tiny, ubiquitous dongle gives the iPhone access to dozens of ANT+ sensors, and more fitness apps than any other system — turning your iPhone into a fitness-tracking powerhouse.

Then in January, Wahoo one-upped itself and introduced the Wahoo Blue Bluetooth heart-rate strap, which completely bypasses ANT+ and instead communicates via low-energy Bluetooth v4.0. Does this mean the Key is obsolete? Not by a long shot.

The Good:

Every conceivable fitness-related measurement — heart rate, bicycle pedal cadence, power output, stride, you name it — has an ANT+ sensor to measure it, and can theoretically be paired with the Key (you can also purchase a variety of ANT+ sensors directly from Wahoo, like the HR strap and bike speed/cadence sensor we tested here).  But the Wahoo Key is not only exemplary because how many sensors it’s compatible with — it also shares its collected data with more apps than any other system. The ever-popular Runkeepeer, and our favorite cycling app, Cyclemeter, are just two of the many apps the Key is compatible with.

Heck, even Wahoo’s own fitness app is fantastic. It’s well-designed, easy to read, comes with a wide choice of readout pages that can be selectively included and includes everything you need for a wide range of activities. About the only thing that disappoints is that the modules themselves aren’t customizable for each screen.

Range for the key is pretty good. I was able to shove my iPhone in a jacket pocket, or strap in onto my arm with an armband (Wahoo sells one that has a slot for the dongle) while still receiving signals from the speed/cadence and heart-rate sensors.

Both the Wahoo HR strap that came with the package, and an older Garmin strap that came with my well-used Forerunner 405, paired remarkably quickly and painlessly (though only one strap can be paired at a time, of course) using the key’s utility app.

For now, Wahoo’s use of Bluetooth is limited to its HR strap; everything else requires ANT+, which means the Fisica dongle is still king. For now.

The Bad:

I’m not sure why, but I actually had a little trouble getting Cyclemeter to wake up to the fact I had a heart-rate monitor attached; I’m assuming this was a fault of the app, not the hardware though.

Update: Steve Kusmer, founder of Abvio, the developer behind Cyclemeter, sent us a note suggesting that the reason I wasn’t able to get Cyclemeter to read my heart rate is because the dongle was already communicating with the Wahoo Fisica app. He’s right — I turned off the Fisica app and Cyclemeter quickly picked up my heart rate. 

Dongles are easy to lose or accidentally wash after being left in a pants pocket (ahem).


An essential piece of kit for any even remotely serious athlete with an iPhone.

[xrr rating=90%]

The cadence/speed sensor fit well enough on my Titus Racer-X's massive stay (note that I suffered a brain fart and installed the sensor on the drive side; don't do this).
From left: The Wahoo Fitness App's HR zone screen, main screen and the utility app's HR strap pairing screen.
  • kusmer

    Eli, thanks for the write-up about the cool Wahoo Fitness devices, and your mention of Cyclemeter. It’s possible that what was likely going on is that only one app can connect to a sensor at a time. And so if you had another app running in the background that had previously connected to the sensor, it retained ownership of the sensor. If you remove that app from the list of recent applications, that will shut the app down, and then Cyclemeter could reliably connect to the sensor. — Steve Kusmer, Abvio, makers of Cyclemeter

  • Jeremy Low

    thanks for your review, was just considering between this and the digifit dongle. in the end, i choose the wahoo key instead of the cheaper digifit. ordered it from http://www.hrmdiscount.com , they are offering free worldwide shipping!