Gear Review: Garmin Forerunner 645 Music

The Garmin Forerunner 645 Music GPS running watch is a powerhouse training device that improves the way you work out.

The Forerunner 645 Music and the slimmed down Garmin Forerunner 35 sit in the sweet spot of the Garmin running watch lineup between the streamlined Garmin vivo series and the souped up Garmin fenix series watches. With GPS tracking, heart rate monitoring and the ability to load up to 500 songs, it will boost your knowledge of how you run so you can fine-tune your training.

Compared with other Garmin running watches, we think the 645 is ideal for any runner looking to boost their fitness.

In this Garmin Forerunner 645 Music review, we’ll give you the low-down on the watch’s hardware, software and what our Fleet Feet testers thought about the device.

Physical specs:

• Display size diameter: 1.2 inches (30.4mm)
• Weight: 42.2 g
• Fits wrist circumferences from 5-8 inches (127mm to 204mm)

Garmin says the battery lasts up to seven days in smartwatch mode and up to five hours in GPS mode with music. One tester found the watch got about four to five days of juice when switching between GPS tracking during multiple three to five mile runs without music and regular smartwatch mode when not exercising.

Battery life will vary widely depending on how a runner uses the watch. Runners who cover more miles, stream music and frequently interact with the interface will drain the battery faster than runners who log shorter activities without music.

To get the most accurate heart rate reading, the watch needs to be worn above the wrist bone—not between your wrist bone and hand—with its back flush against your skin. One tester noted inconsistent readings when the watch wasn’t properly positioned, but the readings returned to normal when the watch band was tightened up.

While the Forerunner 645 Music packs plenty of features to use for everyday training and races, athletes with more off-the-grid goals should check out the Garmin fenix series GPS watches, which include additional navigation and weather tracking features.

Conclusion

The Garmin Forerunner 645 Music is a practical and stylish Garmin GPS running watch that delivers a trove of activity data without the need for additional devices. With accurate run tracking, heart rate monitoring and app integration, most runners will find the 645 Music does everything they need to train smarter.

Still not convinced? Don’t sweat it. Fleet Feet's return policy means you can test drive your shoes and gear without risk. If you’re not happy with the way your gear performs, looks or fits, we’ll take it back within 60 days. Plus, you’ll get free return shipping on all fleetfeet.com orders. That's our Happy Fit Guarantee.