Garmin Forerunner 645 Music review

Watch review

Quick verdict

The Forerunner 645 adds music, but is currently limited by the lack of support from music streaming services. That makes the headlines of an otherwise handsome fitness tracker with smartwatch battery life and numerous adjustments dull. It is also a bit expensive.


  • Compact design
  • Comfortable to wear
  • Excellent sports and activity tracking
  • Can use Bluetooth headphones


  • Music not fully realised
  • Garmin Pay not widely supported
  • Battery life could be better
  • Price a little high

While the smartwatch revolution seems to have stumbled, fitness and exercise equipment has grown and been adapted. Companies like Garmin have outdone the smartwatch generation in many ways, focusing on features that create value rather than distraction.

Take the Garmin 645 Music: It brings music to the Garmin family, along with mobile payments, smartphone notifications and customization. You are sitting on a platform that not only records your activities, but also provides your statistics. It’s as smart as any other smartwatch and more.

The first Forerunner devices – the first to have GPS tracking on your wrist – were huge. As the technology evolved, Garmin faced the challenge of making devices small enough to increase their appeal, especially for those with smaller wrists.

Advanced technology brings many of these things with it and in the 645 Music you have a watch that is still sporty but much slimmer than models a few years ago. It’s also smaller than the 700 Series and 900 Series, and that produced some additional comments when we carried the 645 Music. It’s a good size without being over the top.

The metal ring that surrounds the display of the 645 is a highlight and is inspired by the styling of Vivoactive 3. In fact, there is a big overlap between Garmin’s “sports” and “lifestyle” models. The biggest difference is that Forerunner uses buttons and Vivoactive is based on a touch screen. It’s difficult to use touchscreen user interfaces, so we prefer the buttons.

Elsewhere, the body of the 645 is made of polycarbonate with quick release straps, which can be changed if necessary. There are different colors, with the rose gold in our test model instead of stainless steel accents.

Let’s talk about music

  • Bluetooth connection to headphones
  • Up to 500 song storage
  • Only supports music sideloading 

Music on the go was quickly taken over by smartwatches and has been featured in some running watches like TomTom Spark for several years. It is also a function of Fitbit Ionic. So it was inevitable that Garmin found a solution. In fact, it is very welcome, you can listen to music through Bluetooth headphones without needing a phone.

However, you must first put the music on your watch. And this is still a violin that requires a connection to your PC to transfer your own music. At the start, Garmin had said that he would support Deezer, but that has not happened yet. It’s still in progress, but it’s currently not a feature, so there’s no meaningful synchronization of playlists.

The connection to Bluetooth headphones is pretty simple. Like other accessories from the Garmin Universe, you would simply put your headset in pairing mode and look for it. We found it reliable and made a connection to the excellent Libratone Track +. Together, they make a great combination for running.

Controlling music is not the most logical setting in the normal flow of widget screens. However, you must manually add the screen to your activity screens if you just want to control the music while walking. We noticed that we used the volume, pause, and skip headphones controls. Here’s everything you need to know about how the music controls are accessible through the clock. It’s not the best experience right now.

Features: It’s all about the data

  • Heart rate, GPS, altitude, cadence, motion
  • Running, cycling, swimming and other sports
  • Huge ecosystem of sensors

Over the last few years, we’ve seen Garmin turn from a sports-tracking-only device into a lifestyle device. People no longer just strap on the watch to run, they may wear it all the time. So it’s no surprise that Garmin Forerunner 645 Music takes steps and sleep tracking, keeps you moving, and reaches your weekly intensity goals along the way.

A full-day heart rate measurement is also provided so you can keep an eye on your average heart rate thanks to the rear-side optical heart rate sensor. We’ve found that the Elevate Heart Rate Monitor delivers accurate results that match other Garmin devices and reach the highest and average values ​​we would expect.

One of Garmin’s inherent advantages is its broad compatibility with other Garmin sensors. This may be an old heart rate sensor from a previous watch, a cadence sensor on your bike, or a number of other sensors within the company’s ecosystem. It’s very easy to add sensors to get more accurate or more specific data. This is perfect for those who decide they want to add an accurate swim or bike tracking to the watch. If you have a chest strap, some functions are unlocked, eg. For example, the heart rate variability stress test, which requires the accuracy of a chest strap to give you a measure.

The watch also includes a barometric altimeter, a compass, a thermometer and a GPS, as well as motion sensors to capture a whole host of other data. There you went, temperature, altitude change, distance, speed, cadence, steps and power state. There are basic navigation and support options for routes, as well as the ability to track the way back to the start of your run (great for running new routes or traveling) and LiveTrack over a connected phone (ideal to let loved ones know where you are these long rides are).

What all this data means is a set of metrics to track your sports training, performance, and progress. It is also more than more rivals. The Garmin Connect app provides some insights. You get all the graphics to track your performance over a period of time. In some cases, however, this can be data that a coach uses. Do you want to increase your running speed? You may need to focus on increasing your cadence.

There are some elements that we really like, like the training status. This looks at the training volume and training intensity and gives you an idea of ​​where you are. You want to be in the “productive” stages so that you know that your exercise benefits profits. When the intensity drops, your status changes to unproductive. This goes hand in hand with the recovery time. Have a hard session and Garmin will tell you how long you should rest. Because overtraining is a problem, it can help prevent it. However, it only works on averages and does not know your individual physiology or training goals.

In terms of sports support, swimming, running and cycling are the mainstays – there is no golfing support (see the higher Forerunner, Fenix or Approach devices), but you can determine how you track the workouts in the gym, create custom sports and completely customize the information screens you serve. For example, we selected the Garmin Forerunner 645 for the Three Peaks Challenge with the “Walking” settings and an additional navigation display.

Garmin Forerunner 645 Music battery life

  • Realistic 5 day battery life 

With so much data collected, Garmin has a lot to do to harness his energy. The quoted paper life is a week, but that’s somewhat generous in our experience. Have three decent runs with headphones connected to your music and you look more like 5 days in life.

In terms of the actual event time, you will get around 10-12 hours of activity tracking before worrying about battery life (without music). We tested this on the Three Peaks, which took us 10 hours, with about 25 percent left. Therefore, we wanted to recharge before the 5 hours on the last mountain.

How is this comparable to other devices? The battery life is not as long as that of the Garmin Forerunner 935. The flagship of the 9 Series is larger and its longevity proves to be true. The Forerunner 645 Music trumps the Fitbit Ionic by keeping longer despite similar specifications. Compared to traditional smartwatches like Apple Watch or Wear OS devices, the Garmin more than doubles its lifetime.

Garmin Connect, app and smartwatch functions

  • Great app for data
  • Smartwatch notifications and smart replies on Android
  • Garmin Pay not widely supported by UK banks 

All your data is collected in Garmin Connect (running on Android or iPhone) to give you access to your information on the go. The app also returns data to the clock so you can see appointments like calendar events, weather and notifications.

Garmin Connect has become more of a lifestyle over the last few years – it keeps track of all types of data, not just the data that comes from the clock – and it’s easy to customize with clear statistics. The website equivalent is, frankly, a bit chaotic compared to Polar Flow or Fitbit’s Dashboard, but we really like the smartphone app.

You can also share data with other services. With native support for Strava, you can track your Strava segments. In addition, you can easily share your stats by placing your data on a social media photo or photo (#garmin).

Synchronizing and connectivity are good, and moving your device to a new phone is not a problem. Even using multiple Garmin devices is not a problem – and TrueUp syncs between devices. So, if you use separate devices for cycling and running, this is the case of combined training status rather than ignoring one another (both devices must be compatible).

There are many customization options, and while the selection of apps may not match those offered by Wear OS or Watch OS (Google and Apple), we do not believe these wearables are apps.

Garmin Pay is also supported in the 645, ie contactless payment on the go. This is great for those who want to run and then want to have a milkshake on the way home as a cooldown. In Britain, however, the list of supported banks is rather unfruitful. If you want to use Garmin Pay, you may need to open an account for this reason. US users are better served.

Notifications provide intelligent answers for Android users as well as a complete customization of notifications you make or do not want. There is no voice control, as you might do with some smart watches, but you will not be left in the dark: Garmin is not just sport, it’s sport.


The Garmin Forerunner 645 Music breaks new ground for Garmin and offers a wider feature set than previous devices, including music (though there’s a slightly cheaper version with no music, if you prefer).

This watch is really about athletic performance. Although it can compete with other smartwatches with notifications and features, it surpasses them in sports data. This is supported by the kind of battery life that other smartwatches can only dream of. This means that you can spend a long weekend, being connected while watching the activity, and not having to pack a charger.

In terms of device design, the 645 reduces the aperture and volume for a slimmer sports device. It’s still a bulky design with its five buttons (see Vivoactive 3 Music if you do not want all those buttons), but it’s comfortable to wear and waterproof enough to swim and fight a sweat.

However, it is the headline music that could be better. At the moment, it’s really a case of downloading music from your PC, not just syncing playlists. Until its future Deezer future, the 645 is limited in this department.

The bottom line is the Garmin Forerunner 645 Music promises a lot, but the music and pay supplements are not really delivering … yet. With Garmin’s cheaper watches you get a comparable sports experience. Until the music offering becomes more compelling or the price drops, it is better for you to choose a different model, despite the positive benefits described in this review.

Leave a Reply

Your email address will not be published. Required fields are marked *