Review: Garmin Forerunner 255

Garmin’s Forerunner line of GPS-enabled fitness trackers is bewilderingly complex. Also, the company updates Forerunner models so often even those of us who test them for a living sometimes have trouble keeping up. That’s a good thing—new features are almost always a plus—but it does make picking the right model a challenge.

To further complicate your decision, in 2022 Garmin added the Forerunner 255. The latest model brings multiband GPS support, a barometric altimeter, and much-improved sleep tracking, among several dozen other welcome additions. The result is a multisport, runner-friendly watch. At $350, this is one of the best value-to-features watches in the Garmin lineup.

Photograph: Garmin

For years now I have used the Garmin 245, which falls in the middle of Garmin's Forerunner line and is aimed mainly at runners. With the release of the Forerunner 255, Garmin has retired the 245.

As with any fitness tracker, how much any of this will benefit you depends on what you're doing. For reference, my workout routine is body-weight-based, with alternating walking and sprinting sessions thrown in throughout the week. I also used the 255 on hikes, paddleboarding, and for sleep tracking.

Like nearly all non-touch Garmin watches, the Forerunner 255 has five buttons, three on the left side and two on the right. I find the buttons more reliable to navigate with than the touchscreen models, but the main thing to note is there's no touchscreen here. The watch face is fully customizable, with a good selection of default faces you can use to customize to your liking.

There are quite a few new features worth mentioning, but the one I was most excited about is the sleep tracking. The Forerunner 255 tracks heart-rate variability (HRV) and sleep stages and gives you an overall Sleep Score, with a new Morning Report, which includes the company’s Body Battery feature as well as a daily greeting, the weather, and other tidbits. It's similar to what Apple offers.

To test the accuracy of the Forerunner 255, I had my wife, who uses an Oura ring to track sleep, use it for a few weeks. (The Forerunner requires 19 days of use before it will start making recommendations based on the sleep data it has collected.) To keep this review to a reasonable length, the result was that she is no longer worried about replacing her Oura, given that company’s disappointing trajectory. The Forerunner's data mostly matched that of the Oura and is very nearly as comprehensive. But it doesn't track body temperature while sleeping and is missing some other features the Oura offers.

I particularly liked my Morning Report, a good way to get a quick overview of where you're at and what you want to do that day, training-wise. The other thing that jumped out at me in the first week was the new auto-detection features. 

Once I started the Endurance Training activity, the Forerunner knew when I was doing push-ups and logged them. It knew when I was walking, running, and resting. It's particularly well-suited to interval training thanks to the automatic detection. Also useful are the training and recovery tools, which previous models I've used lack. They're not as comprehensive as what you'll find in the more expensive Forerunner 955, but together with the sleep tracking they can give you a more accurate impression of where you're at and how to get to where you want to be.

That said, fitness tracking remains an inexact science. The Forerunner 255 is convinced I climb seven flights of stairs a day on average. I assure you, I do not.

Photograph: Garmin

Other features worth mentioning include multiband GPS support (with dual-frequency support), which makes for more accurate GPS tracking, a barometric altimeter and compass (useful for hitting the trail), and a ton more cycling support, including VO₂ max and the ability to connect to many bike gadgets via Bluetooth. The GPS support is worth noting because it is much more accurate, but it takes a heavy toll on the battery.

Battery life on the 255 is quite good overall. In fact, it's good enough that I didn't pay much attention to it. Using it the way I do, with an activity on for about an hour a day, GPS tracking on, but Pulse Ox set to on-demand only, I got about five days. 

The longer you use an activity the more battery it'll take. While I had the watch, my wife did a 12-hour walk, so naturally I gave it to her to test. When she got back, the battery had run down to about 40 percent, which would put it about 30 hours of continuous use.  I find the real key to long battery life is to turn off continuous pulse-ox measurements and other battery-intensive features when you don't need them.

The final thing worth mentioning is that you can now fully configure your watch using the Garmin app on your phone. Naturally you can change settings from the watch, but the ability to set things up on your phone makes life so much easier, especially given the emphasis here on creating workout plans through Garmin Coach based on future events. The daily suggested workouts can be connected to calendar events, like an upcoming race. The app can automatically create workouts for that distance.

The Forerunner 255 comes in two sizes now, 42 mm and 46 mm. (The 42 mm is listed as the 255S.) They are both $349. A Forerunner 255 Music model is $399 and can store roughly 500 songs directly on the watch. Although I tested the 255 Music, it's not a feature I use much. It works fine. 

The problem with fitness trackers is that most of us use maybe half of the features available. Do you use the features the Forerunner 255 offers? Personally, I find it a huge upgrade over the 245 and Venu for the sleep-tracking features. 

But if you're serious about competing in triathlons, the 945 is the watch to get. It's expensive but powerful. If you don't care about the sleep-tracking features and have no need for new automatic run/walk/stand detection, the far cheaper Garmin 45 might fit the bill.