The highly anticipated Forerunner 255 has arrived. And this time around, Garmin isn’t content with a simple software update. This new model comes with some features usually reserved for high-end watches and offers one of the most attractive tech specs: multi-band GPS, Garmin Pay, barometric altimeter, triathlon mode… this Forerunner 255 has it all something convincing.
Compared to the 245 model, there are many novelties. First, we found two case sizes, as is the case with Garmin now. The classic 255 was priced at 349.99 euros, so it was accompanied by the more compact 255S, sold at the same price. If the first uses a 46mm case, the second is 41mm, especially for female audiences.
Each has a “music” version, which is 50 euros more. The Forerunner 255 Music and 255S Music can store up to 500 songs in their internal memory, so you don’t need to carry your smartphone to listen to. Note that between the classic version and the music version, the only difference is the music storage.
Ergonomics and Design
This Forerunner 255 has a relatively large enclosure (45.6 x 45.6 x 12.9 mm). If you have small wrists, we naturally recommend moving to the 255S version. Despite its size, the Forerunner 255 is a pleasure to wear on the wrist. The case is made of fiber-reinforced polymer and can be worn comfortably for hours. Same observation with the silicone strap, it fits all wrist circumferences and doesn’t irritate in any way even when wet.
This Forerunner 255 is also water resistant up to 5 ATM. This means you can use it for a leisurely shower or swimming. But be careful, if you go diving, surfing, or jet skiing, a drastic change in pressure may make things better.
Who says big case, often say big screen. The Forerunner 255’s tablet isn’t huge, it’s over 1.3 inches thick, or 0.2 inches more than the 245. At the same time, the resolution has risen from the previous 240 x 240 pixels to 260 x 260 pixels. This slight gain helps to increase the display of the Garmin interface. Manufacturers remain faithful to non-touch transflective MIP screens, which are both legible and unflattering. For example, we’re far from what the Venu 2 has to offer.
This Forerunner 255 features five buttons and a non-touch screen that provides the exact same navigation as previous Garmin models. So there’s a validation button, a backspace, two for scrolling through menus, and the last one for backlighting. Nonetheless, the experience offered on the wrist continues to enrich, especially in terms of personalization and data analysis.
So when we wake up, we’re entitled to a “morning report”: a summary of our night, personalised training recommendations or even data about our recovery or – novelty – recorded if we wore the watch to sleep Heart rate changes. Although trivial, this data often turns out to be correlated, allowing us to better understand our state.
Another novelty is the arrival of Garmin Pay on the 200 series, offering more autonomy during sports outings. A welcome feature.
We’ve also noticed the presence of deploying a “race widget” to plan sessions or Live Tracks, a tool that allows our friends to follow our efforts in real-time. There are many nice additions to the Forerunner 200 series’ existing catalog of features, such as Garmin Coach, PacePro or turn-by-turn navigation.
On the wrist, large amounts of data can be quickly accessed. Real-time heart rate, training status, sleep tracking, steps, “body battery” energy levels, floors climbed, calories burned or sunrise or sunset times… by going into menus, sometimes drafts, graphs, curves and other very specific Data is available. We still recommend viewing all this data on a larger screen via Garmin Connect on your smartphone or computer.
If Forerunners were designed for runners in the first place, the 255 offers about 30 other sports configurations on the wrist: biathlon, triathlon and even swimming. During a session, each screen displayed can be customized to accommodate up to 6 metrics of your choice. A very pleasant freedom of use that allows you to fine-tune your performance at a glance. Especially with so many choices: stopwatch, pace, distance, speed, cadence, vertical vibrometer, altitude, ascent, real-time or average heart rate… Also note that the power delivered for the full stroke can now be displayed. However, you have to go through an external power sensor, which the Forerunner 255 cannot calculate on its own. When hiking or trail running, you can use the watch to display your GPS track and activate an option to get back to where you started. High-end models from American manufacturers, especially the Fenix 7, have leapfrogged in functionality. This high level of personalization contributes to the comfort of using this watch.
Like other Forerunner models, the screen is continuously lit and automatically backlit when wrist movement is detected. In use, this routine provides very good readability. But be careful: Without the onboard light sensor, the backlight can sometimes be too powerful, especially at night or when you wake up.
On this Forerunner 255, notifications are displayed very clearly. The text is large enough to scan at a glance. Messages from WhatsApp come with the app logo, such as messages from Messenger. However, the number of recognized apps is still too small, and we often find ourselves reading content without knowing its source.
Having been around for generations, the music controls are still just as useful. The display is successful and the navigation is efficient. Not to mention the storage – up to 500 titles – can hold beautiful playlists.
Purpose and Accuracy
This Garmin Forerunner 255 integrates a series of sensors. There are GPS, heart rate monitors, barometric altimeters, gyroscopes, accelerometers, thermometers and even pulse oximeters.
Let’s start with GPS, which now allows three modes of operation: GPS only, multi-GNSS (combined with GPS, GLONASS, and Galileo), and dual-frequency multi-GNSS. As the name suggests, the last mode doubles the frequency of GPS and GLONASS tracking. It’s especially effective, even in towns where its accuracy remains satisfactory. Regardless of GPS mode or smartphone. The layout here is more realistic.
On its own, heart rate monitors provide good monitoring in almost all situations. On long outings without sudden heart rate changes, the watch provided similar results to those obtained with the Polar H10 chest strap, which served as our reference.
During interval workouts, on the other hand, the Forerunner 255 will follow drastic changes in heart rate, but only with heart rate changes that are separated by a few minutes. In the capture below, we can clearly guess that there is a 6 x 800 meter interval of movement with a 3 minute break in the last two thirds of the curve. These curves are almost identical to those marked on the Polar H10 chest strap. Unfortunately, in the first third of the graph, it’s much less accurate. This part corresponds to a speed change over 30 seconds. The Forerunner 255 is more difficult to follow when these changes are strong and short-lived.
Therefore, the Forerunner 255 will be suitable for most situations, especially in competitions. However, you will have to rely less on it during training sessions based solely on very rapid cardio changes.
Successful Garmin Connect application.
Very accurate GPS.
10 days of autonomy.
Non-touch transflective screen.
Show summary notifications.
Cardiac monitoring is less accurate during periods of rapid frequency change.
How does grading work?
Let’s not get too carried away, the Forerunner 255 is a great watch for runners. Its GPS is accurate, its cardio is generally very satisfying, its autonomy is very comfortable… icing on the cake, the 255 opens up to triathlons and adds software recommendations to optimize its fit performance.