Garmin Forerunner 45 vs. Vivoactive 3: Which Should You Pick?

The Garmin Forerunner 45 and Vivoactive 3 are both solid options as entry-level GPS watches. They track running and other popular activities, and you can find the watches for less than $200. If you’re having trouble deciding between the two, I totally feel you! In this post, I’ll go over their similarities and reasons you might choose one over the other.

As some context for my review, I’m mainly a distance runner who trains for half and full marathons. I’ve also dabbled in trail running and triathlons, and I cross-train pretty often. I’ve owned the Vivoactive 3 Music for over a year, and I borrowed my roommate’s Forerunner 45S (smaller version of the 45) for this review.

Note that this post contains affiliate links, meaning that I earn a small commission on any purchases made through these links. This doesn’t cost you any extra, and it’s a great way to support my blog if you found this post helpful!

Things in Common: Garmin Forerunner 45 and Vivoactive 3

These watches both:

• Track running and biking (indoors and outdoors), cardio, elliptical training, stair stepping, and yoga
• Show general fitness stats like steps, heart rate, sleep, stress, and VO2 max
• Offer basic smartwatch capabilities (text notifications, calendar, weather, control smartphone music, find my phone)
• Are waterproof up to 5 meters
• Have the same battery life: 7 days smartwatch and 13 hours GPS (and 5 hours GPS + music for the Vivoactive 3 Music)
• Offer safety features like LiveTrack and Incident Detection (note that only the Vivoactive 3 Music only has this feature, and not the regular version); your watch must be connected to your phone, however

Now that we’ve covered their similarities, let’s take a look at how these watches differ.

Why to Pick the Garmin Forerunner 45

This is not my arm lol—had a friend model

The Forerunner 45 is a solid entry-level GPS watch from the latest generation of Garmin, having been released in April 2019.

The biggest difference between the Forerunner 45 and the Vivoactive 3 is its lack of a touchscreen. Its button navigation is intuitive, so you’ll have no problem figuring out how the watch works. The Vivoactive 3 is easy to use as well, but it has a touchscreen. I haven’t had any big issues with it, and have been able to use the touchscreen just fine while swimming and exercising in the rain. There are some situations where you might prefer button navigation though:

• If you wear your watch while showering—sometimes the touchscreen will activate in warm showers and change my settings. Keep in mind that you can lock the touchscreen to avoid this though!
• If you live an a cold climate and wear gloves to run—I use touchscreen gloves and they work fine, but if you’re planning to program fancy workouts that require a lot of watch navigation, you might prefer a non-touchscreen watch.
• If you want to track sleep with the watch—you might accidentally activate the Vivoactive 3 touchscreen and be disturbed by the backlight. You can manually turn the backlight off each night, but it’s more work.

If any of these apply to you, the Forerunner 45 might be a better choice.

Another difference is the size of the watches. The Forerunner 45 also comes in a smaller size, the Forerunner 45S. Both weigh less than the Vivoactive 3. Here are the weights:

• Forerunner 45S: 32g
• Forerunner 45: 36g
• Vivoactive 3: 43g
• Vivoactive 3 Music: 39g

This means that the Vivoactive 3 is 34% heavier than Forerunner 45S, and 22% heavier than the Forerunner 45 (the Vivoactive 3 Music is 22% heavier than the Forerunner 45S, and 9% heavier than the Forerunner 45). Keep in mind that these are all pretty normal GPS watch weights though.

This difference is mainly because the Forerunner 45 has a smaller screen at 26.3mm vs. the Vivoactive’s 30.4mm. (The Forerunner 45 and 45S have the same size screen—only the case is different, as one is made for smaller wrists). The smaller size and weight do make a difference in comfort. That’s not to say that I find Vivoactive 3 Music uncomfortable; the Forerunner 45S just feels especially easy to wear.

Another advantage of the Forerunner 45 are its Audio Prompts. While running, you can get voice updates on pace, lap number, and lap time. You must be connected to your phone, however. This feature isn’t available at all on the Vivoactive series.

One final feature that may be appealing is Body Battery, which monitors your energy levels throughout the day using heart rate variability, stress, and activity. It can help you know when it’s ideal to train hard or rest. I personally don’t find it that useful, as I can generally tell how I’m feeling without a watch. That said, Body Battery can help quantify your energy levels, and can let you know how certain activities impact them (like exercising, napping, frantically running to catch your train, etc).

Why to Pick the Garmin Vivoactive 3

The Vivoactive 3 is an older model, having been released in August 2017 (the music version was released in June 2018). That said, I still consider the Vivoactive 3 the best-value Garmin watch—and I’ve tested 7 of the most popular ones.

One of its biggest advantages is its barometric altimeter. Without this, you can’t track floors climbed, and your elevation stats are less accurate. Unfortunately, several Garmins, including the Forerunner 45 and 245, don’t have altimeters. If you’re worried about elevation data though, you can always sync your workouts to Strava afterwards, which will correct your stats. You just won’t have the most accurate data in your Garmin Connect app.

Another perk of the Vivoactive 3 are its many tracking profiles. The Forerunner 45 doesn’t track pool swimming, but the Vivoactive 3 does. I’ve found the pool swimming feature to really fluctuate in accuracy, but I’m also not a strong and consistent swimmer. Others say that it’s spot on.

Here’s a look at the activities the Vivoactive 3 can track that the Forerunner 45 can’t:

Pool swimming	Golfing
Strength	Skiing
Stair stepping	XC skiing
Floor climbing	Snowboarding
Indoor rowing	Stand up paddleboarding
Rowing

If you get the music version of the Vivoactive 3 (what I have), you can also store and play music from your watch when connected to Bluetooth headphones. You can also use Spotify Premium, Amazon Music, and Deezer, as long as you download your playlists beforehand. The Vivoactive 3 Music is the watch pictured in this post—the non-music version looks different, as it has metal bezel.

The Vivoactive 3 also has Garmin Pay, which allows you to make contactless payments with your watch (no need for your card or phone!). It’s compatible with many major banks and cards, and you can use it at retailers that accept contactless payments. If you plan to use this option, just be sure to check compatibility with your country, bank, and card.

Finally, the Vivoactive 3 looks more like a lifestyle watch than the Forerunner 45. It also feels more “expensive” as it’s less plastic-y and has a more flexible band (the Forerunner 45 band is automatically curved). If you want a GPS watch that looks more discreet, you might consider the Vivoactive 3. (It’s also kind of funny that the Vivoactive 3 feels more expensive, as it’s generally $50-70 cheaper than the Forerunner 45, at least on Amazon).

Check out my in-depth review of the Vivoactive 3 Music for more info.

The Bottom Line

I personally think the Vivoactive 3 is a better value watch, as it has a barometric altimeter and can track more activities. If you want to save some money, you can also generally find the Vivoactive 3 for less than $150 on Amazon. And if having a watch with music is important to you, the Vivoactive 3 Music is one of the cheapest GPS watches that can do that.

There are some reasons you might prefer the Forerunner 45 though. If you don’t want a touchscreen, are looking for an especially light and comfortable watch, or need to use Audio Prompts, you might consider the Forerunner 45 instead.

Where to Buy the Garmin Forerunner 45 and Vivoactive 3

If this review helped you, it would mean a ton if you purchased through my affiliate links. Here are some places to buy these watches, on Amazon and the Garmin website. I also want to encourage you to buy secondhand or from small, local running stores if you can. I don’t get paid if you do that, so if you still want to show your appreciation financially, you’re welcome to buy me a ko-fi.

Amazon:

Forerunner 45 – click the size options if you want the 45S
Vivoactive 3 (non-music)
Vivoactive 3 Music

Garmin:

Forerunner 45 – again, click the size options for the 45S
Vivoactive 3 (non-music)

Other retailers:

Swappa (used electronics)
REI
Dick’s Sporting Goods

Other Watches You Might Consider

If you were also considering the Forerunner 235, check out these comparisons:

• Garmin Forerunner 45 vs. 235
• Garmin Vivoactive 3 vs. Forerunner 235

If you’re looking for more training features and have a larger budget ($300-350), you might also want to check out these comparisons:

• Forerunner 245 vs. Vivoactive 4
• COROS APEX vs. Forerunner 245

I hope you found this post helpful in making a decision! As always, feel free to reach out with any questions.

Happy training,