While they are both extremely versatile GPS watches, there are some key differences between the two units.
To help you understand which watch is better suited to your needs, we’re going to unpack all the key similarities and all the key differences. But before we do, it’s worth pointing out the biggest differences, right off the bat.
Key Difference 1: The Forerunner 645 supports Garmin advanced running dynamics and Garmin Running Power. This is ultimately why it is a better choice for runners. However, you do need to purchase one of the following 3 accessories in order to unlock advanced running dynamics and running power.
- Garmin HRM-Run
- Garmin HRM-Tri
- Garmin Running Dynamics Pod
Key Difference 2: The Garmin Vivoactive 3 Music has golf tracking built into the watch. This is super handy for golfers, because you basically get an awesome activity tracker that doubles as an excellent golf watch. If you don’t play golf, then obviously this feature shouldn’t affect your choice of watch, but if you do, it could be a gamechanger.
Key Difference 3: The Vivoactive 3 has a touchscreen, whereas the Forerunner 645 relies exclusively on buttons to control the watch. This is one of the reasons that the Vivoactive 3 functions better as a smartwatch, and the the Forerunner 645 functions better as a running watch.
Basically, the buttons of the FR645 are a bit more user friendly when you’re actually running. However, the touchscreen of the Vivoactive 3 Music is still perfectly fine for most runners, and it feels more like a smartwatch when you aren’t exercising.
Now let’s breakdown all of this info into some super simple tables.
Garmin Forerunner 645 vs Vivoactive 3 Music - Key Similarities
Forerunner 645SEE PRICE
Vivoactive 3SEE PRICE
Garmin Forerunner 645 vs Vivoactive 3 Music - Key Differences
Forerunner 645 vs Vivoactive 3 - Sports Modes
|Forerunner 645 - Sports Modes||Vivoactive 3 - Sports Modes|
|01) Strength Training||01) Strength Training|
|02) Cardio Training||02) Cardio Training|
|03) Elliptical Training||03) Elliptical Training|
|04) Stair Stepping||04) Stair Stepping|
|05) Floor Climbing||05) Floor Climbing|
|06) Indoor Rowing||06) Indoor Rowing|
|07) Yoga||07) Yoga|
|08) Running||08) Running|
|09) Treadmill Running||09) Treadmill Running|
|10) Indoor Track Running||10) Indoor Track Running|
|11) Skiing||11) Skiing|
|12) Snowboarding||12) Snowboarding|
|13) Cross Country Skiing||13) Cross Country Skiing|
|14) Stand Up Paddleboarding||14) Stand Up Paddleboarding|
|15) Rowing||15) Rowing|
|16) Cycling||16) Cycling|
|17) Indoor Cycling||17) Indoor Cycling|
|18) Pool Swimming||18) Pool Swimming|
|19) Golf Mode|
It’s pretty clear to see that both watches are very well rounded in terms of the sports modes that they offer.
However, if you don’t play golf, this is a non-concern, because the FR645 matches the Vivoactive 3 music in every other sports/activity mode.
Visual Summary of Key Features
Garmin Forerunner 645 - Features Summary
So which one should you buy?
These watches are about as similar as it gets, technically speaking.
The primary advantages of the FR645 is that it has advanced running dynamics and Garmin Running Power.
The primary advantages of the Vivoactive 3 Music is that it has golf tracking and a touchscreen.
In my honest opinion, it all comes down to this.
The Final Word
Ultimately, the Forerunner 645 is better suited to runners, so if you’re addicted to collecting kilometers, it’s definitely the right choice.
However, the Vivoactive 3 Music has dropped in price quite a lot since it was first released. That makes it a very compelling option, because it’s so similar to the Forerunner 645 in terms of technological features. It’s basically a Forerunner 645, with a touchscreen and golf mode, minus the advanced running stats.