Garmin’s Forerunner series of smart watches/activity trackers have long been a favorite of triathletes and runners. But is the newest incarnation, the Forerunner 645 Music, the right choice for cyclists?

Review: Garmin 645 Forerunner Watch is a great option for multisport athletes

The Forerunner 645 Music replaced my Fitbit Versa, which wasn’t compatible with my Garmin 820. My original goal was to find a smart watch with a built-in heart-rate monitor, as I rarely bother to wear my HR strap on rides. For the first two months I owned the watch, I wasn’t able to figure out how to broadcast my heart-rate signal; it wasn’t until a Garmin rep pointed me to the insanely easy instructions that I was able to do it.

Review: Garmin 645 Forerunner Watch is a great option for multisport athletes

Heart-rate accuracy was pretty good, especially for a wrist-worn device. There were a few blips compared to my chest-strap HRM, but overall, it was on the money. A couple of times I did have to adjust the watch, either by tightening it or moving it slightly lower on my wrist, to get an accurate reading.

Review: Garmin 645 Forerunner Watch is a great option for multisport athletes

The watch is incredibly lightweight and comfortable. The rubber watchband felt a touch flimsy when I put it on for the first time, but I haven’t noticed any kind of stretching or excessive wear in the three months I’ve been wearing it virtually nonstop. Battery life is excellent, needing a charge only about once every five to seven days. Charging generally took less than an hour. The time display is crisp, albeit a touch dark before touching the navigation keys. Navigating through the various menus and options via the buttons on the side of the device wasn’t very intuitive for me, but previous Forerunner users should have an easier time.

Review: Garmin 645 Forerunner Watch is a great option for multisport athletes

Speaking of navigation, Garmin built its reputation on GPS, so location accuracy is pretty spot on. While you can download courses with breadcrumb navigation or track your way back to a starting point, it doesn’t have the multitude of map capabilities and features that we take for granted on our smart phones. This isn’t a big deal if you know the routes you’re riding, but more adventurous riders who routinely tackle new roads and trails may want to consider another device.

I’m not a data geek, so many of the info sets – VO2 max and lactate threshold, for example – are overkill for me, but could be useful for more numbers-driven athletes. That said, I do track my power numbers pretty closely and was most disappointed by the lack of compatibility with my PowerTap. A third-party app on the GarminConnect store promised to add that function, but I was never able to get it to work on the watch. Assuming you have a sensor hooked up to your wheel, the Forerunner will track your speed and cadence, giving you needed information if you’re riding indoors.

Although I’m primarily a cyclist, the Forerunner offers a plethora of other activity options – running, swimming, or even yoga. On a recent trip to Wisconsin, I was excited to try out the cross-country skiing option, but I was so cold, I forgot to start the watch. (In my defense, it was during the polar vortex.) I’d love it if the Forerunner were able to automatically recognize when the user begins an activity, but that might be a feature for a future watch.

Sleep details are nice, but I found the Forerunner can confuse dozing with other sedentary activities. Logging onto the app and seeing it think I was sleeping 11 or 13 hours a night made me realize I need to be getting up and moving about instead of just sinking into my couch at the end of the day.

Review: Garmin 645 Forerunner Watch is a great option for multisport athletes

Plan ahead if you want to listen to music; you can’t stream Spotify, only download and listen to songs from that app and a few others. The Forerunner paired quickly with my Bluetooth headphones, and soon enough the new John Prine album became my soundtrack for meandering through my neighborhood. (I don’t listen to music while I’m on the bike.) Garmin claims you can fit about 500 songs on the watch, although I haven’t attempted to load nearly that many tunes on it.

So what’s the verdict? The Forerunner 645 Music is a nice everyday smart watch, a great tool to track all my other outdoor activities, as well as a more than capable backup in case I forget my handlebar-mounted computer at home. For weekend warriors, this is a great do-(almost) everything option, but for adventure- or power-obsessed riders, it’s more of a complimentary device.

-Review by Robert Annis

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Lucas Q
Lucas Q
3 years ago

I picked up one of these for myself in December and I agree with everything in this post. Best purchase I’ve made in a long time and I enjoy all the little stat tracking things and information