Coros Apex 4 review – Calling from the Wild

Tags: Review | Coros | Smart

29.12.2025 | 10 MIN

Three years. That’s how long we waited for the fourth generation of the Coros Apex 4. When someone takes that long, expectations run high. Did the Apex 4 live up to them?

What stood out most to me about the Coros Apex 4:

• well-executed design
• a microphone and a genuinely good speaker
• the ability to make calls
• sticking with MIP display technology
• a moody heart rate sensor
• snappier performance in both the UI and maps
• more detailed maps

Some of you may be asking: Where the hell did Apex 3 go? I don’t know who came up with it, but supposedly Coros didn’t want someone to land on their website and find a model with a higher number in a different lineup (e.g., Pace 4) even if it’s less feature-rich. That’s a little hint we’ll probably never see a Vertix 3 either, and we’ll “go 4” there as well. I still believe people aren’t clueless, but Coros clearly thinks otherwise.

Two sizes, two colors

If not with names, Coros at least kept sizes and colors simple.

You get two diameters — 42 and 46 mm. And two colors for each size — black and white. One band material — silicone. Honestly, that’s great. Let’s be real: 90% of people will buy one of those two colors anyway, and the remaining 10% will survive with black or white.

While the Coros Nomad looks traced straight from the Garmin Instinct line, the Apex 4 has a unique design. I really like how Coros played with the lugs, which extend into the equally interestingly shaped bezel where there’s a special “cut-out” for them.

I tested the 42 mm version, which had me a bit hesitant since I’m used to large watch diameters (my daily watch is 51 mm), but I admit it wore really well. It even made me wonder whether my daily watch might be unnecessarily big.

The case combines plastic with Grade 5 titanium. The slightly recessed sapphire crystal is a nice touch. Frankly, the materials are quite premium for the watch’s price point.

What elevated my experience most, though, was the unlocking experience. I’ve always resented Coros’s little lock and turned it off right after pairing. It felt pointless. You had to long-press the crown to unlock the watch. That’s not exactly a complex task—and if you wear your watch on your right wrist like I do, your sleeve can manage it for you more than once a day.

Even though I always turned it off, this time I didn’t, because the sound the watch makes right after unlocking is oddly satisfying.

A lineup that sticks to tradition?

In recent years, smartwatch users have split into two camps — those who fell in love with AMOLED and those who remain loyal to MIP.

Things looked iffy for Coros when Pace Pro and then Pace 4 showed up with AMOLED displays. But the riled-up MIP camp calmed a bit with Coros Nomad, and now they can relax even more — Apex 4 still has a MIP display.

In short: AMOLED is richly colored, high-contrast, and much more dynamic. It’s used in smartphones too. But if it were to stay on all the time, battery life would pay a steep price. So it usually turns off. MIP, on the other hand, isn’t as contrasty or colorful and can feel a bit retro, but its greatest strength is that it can stay on permanently and even use sunlight to brighten itself (transflective).

Just like the case, there are two display sizes — 1.4" and 1.2" (260 x 260 and 240 x 240 px).

The technology is largely the same, but I have to praise Coros for smoothness. Controlling the watch with the crown is a bit tedious, as it feels like you have to spin too much just to move one item in a list. The touchscreen solves that. But honestly, I’d love it if a quick crown flick triggered fast scrolling instead of stepping through items one by one.

Another thing that annoys me, paradoxically, is the lock I just praised. The watch doesn’t visually indicate whether it’s currently locked or not. Unless you click the crown (the screen and any other button do nothing), you won’t know.

There are three controls on the case — a rotating crown, a lower button (it cycles widgets on the watch face and takes you one step back), and the new action button. I like this one because it solves exactly what bugs me with other brands — one press takes you to the map and another takes you back. Data screens can be viewed both horizontally and vertically. Imagine you’re on the second data screen, you press the action button, you’re on the map, and pressing it again takes you back to that second screen (not the first). That’s great.

You can also configure the action button for any sport profile. In strength training, it basically offers set switching, but in running it can flip through screens, add a location, or start a new lap. The lower right button is configurable too. The crown also has some configurability: pressing it can instantly pause an activity and show next-step options, or it can first bring up a prompt asking what you want to do. You can therefore finish and save an activity without pausing it first.

There’s an “endless” number of watch faces — exactly 4. And I’m perfectly fine with that. They’re optimized for battery life and no one can cram any nonsense in there.

The watch is very easy to operate — even my colleague Filip could manage it, and as you can see, I enjoy teasing him.

From the watch face, you can scroll both ways through widgets like sleep, heart rate, sunrise and sunset, last activity, barometer, and more. Pressing the crown opens the sport profiles. Long-pressing the lower button opens the control center with alarm settings, camera controls, Find My Phone, map view, etc.

The HR sensor is moody again, but GPS works great

So what sensors do we get in Apex 4? First, quantitatively — accelerometer, barometer, ECG, GPS receiver, gyroscope, compass, pulse oximeter, heart rate sensor, and thermometer.

What most people care about is heart-rate accuracy and positioning.

The GPS receiver can use GPS, Galileo, GLONASS, BeiDou, and QZSS — not just on a single frequency, but dual-frequency. That naturally affects battery life, but you can choose between multiple GPS modes.

Values in parentheses indicate battery life in the given mode with music playback enabled.

It’s nice that Coros finally quotes battery life in standard smartwatch mode with 1-second heart-rate sampling enabled.

Compared with the biggest rivals, the Forerunner 970 lasts about 21 hours in the most accurate GPS mode. Suunto Race 2, on the other hand, manages 55 hours. So the Apex 4 lands somewhere in the middle. To their credit, the case is much smaller than Race 2’s.

Equally important as endurance is quality (which you can apply to other parts of life too). So how do the two most important sensors fare — the GPS receiver and the heart rate sensor?

15.6.2021
Heart rate sensor – everything about it and how can it help you

GPS recording is excellent. Here’s MAX mode on a bike commute:

The watch beautifully draws each bend of the cycle path. And on a bike it’s even trickier because I’m moving faster.

Coros wasn’t shy about showcasing GPS accuracy in the mountains, even claiming on its website: “Our most accurate vertical GPS algorithm yet.”

Heart rate is a bit of a mixed bag. During activity? Lovely. Here’s a treadmill run where I jogged easily for 15 minutes, then 10 minutes at tempo, a short breather, and finished with a tempo run at maximum incline to push the heart rate.

Blue — Coros Apex 4, purple — Polar Verity Sense.

But outside sport the HR sensor was very moody. More than once I was sitting in the morning, my Garmin showed its usual sub-50 bpm, while the Coros read 85. If it happened once, I’d chalk it up to a glitch. But it happened repeatedly — and not just to me. My colleague Kristián noticed the same thing.

Sleep still isn’t scored, and that might be a good thing

For athletes, I consider sleep tracking essential, and Coros naturally shows sleep start and end, the proportion of individual phases, and overall assessment on a five-color scale. What’s nice is that Coros adds written commentary on your total sleep duration, the duration of each phase, and time awake.

At first I was a bit disappointed that Coros still doesn’t have a 0–100 sleep score, but then I realized that might be a good thing. Instead of a number, you get verbal feedback, which is less suggestive. Imagine waking up feeling fine and suddenly seeing a score of 37. Many people start convincing themselves they’re tired. That happens much less with a verbal rating.

What I appreciate is the heart rate range indicator. Within sleep tracking you get three key values — lowest, highest, and average heart rate.

Equally important to me is heart rate variability. The watch shows not only last night’s average, but also a seven-day curve with a shaded range of normal values. This is measured optically, which at night, when the body is at rest, is perfectly fine. It’s also great that Coros lets you take a manual reading using “Wellness check,” where HRV is measured via ECG. During the day, variability is measured optically on an ongoing basis and converted into a stress value on a 0–100 scale.

If you like training metrics, Coros delivers

On the app’s main screen, the first thing you see is the training calendar — absolutely brilliant in my book. At a glance you see plans for the entire week, and you can either build workouts manually or draw from the training library directly from Coros. It doesn’t only cover standard running, but also trail running, cycling, swimming, strength training, indoor climbing, and bouldering. Frankly, Coros outdoes everyone here. I don’t think any other brand has built it out this well.

I also enjoy Effort Pace, which is a grade-adjusted pace, and Coros even adds the slope of the hill — something I believe only Suunto did until now.

The activity summary looks roughly like this:

For strength sessions, the muscle heatmap is handy—it shows which muscles are most taxed based on the exercises you log. I’ll admit I never enjoy logging reps, so my muscle map is always empty.

On the app’s home screen you’ll also find training load, training status, recommended recovery time, and my favorite feature, Running Fitness. It offers a very clear view of your running components — endurance, threshold, speed, and sprint — and uses them to estimate times for various race distances.

Coros is one of the few to offer a full desktop version called Training Hub. You can immerse yourself in training metrics even more, because the pool is simply bigger here.

Source: https://coros.com/traininghub

Apex 4 is the first Coros you can call from

I’ll start with what I personally like most.

Global map coverage (with roughly 27 GB of storage). Much faster, much more detailed (zoom down to 15 meters). Street names, POIs, contour lines, turn-by-turn navigation, and an extremely fast jump to the map via the action button. Coros really nailed this, and it’s clear they’ve honed activity tracking in general down to the details. It shows that real athletes test it, not just random ambassadors.

29.4.2022
4 reasons to choose a smartwatch from Coros

Overall, the maps currently come closest to Garmin’s, and the only thing missing for perfection is color-coded hiking trails.

Another pleasant surprise is not just the microphone (Nomad already had one), but a very satisfying speaker too. Not only does unlocking sound downright awesome, but calls are genuinely high quality on both ends. The only problem is the speaker has no way to expel water. For a while after submerging the watch, you’ll hear basically nothing and calls are almost unusable.

Similarly, actively dialing contacts from the watch is also unusable. The reason is simple — there’s no contact list.

But I’ll be honest… I don’t think I’ve ever actively called anyone from a watch. I just answer calls.

The mere fact that Coros offers calling — and in very high quality — is a big step forward. Within the sporty smartwatch competition, this is above standard.

The speaker and mic also enable voice prompts during activities and the option to record voice notes with a specific location.

So if you’re prepping for a race and want to pre-run the route, you can record notes along the way and then review and plan everything calmly at home.

Otherwise, Coros brings its usual lineup — alarms, Find My Phone, a music player…

Bottom line — Is the Apex 4 worth it?

Honestly, if I were an athlete looking for a training device, I wouldn’t hesitate about the Apex 4. Great design, great battery life, an above-average base of training metrics and plans, quality sensors, quality materials... There’s really nothing to fault (aside from heart-rate readings outside of sport). Coros also added calling, improved the maps, and gave it a fairly reasonable price point.

Looking at it as a reviewer, though, we waited three years for this model. In technology years, that’s practically a device’s entire lifespan. So a really long time. Maybe I’m greedy, but I would’ve hoped for a bit more on the software side. We didn’t get any compelling new features, and I think Coros still has plenty of room in functions that bridge health and sport.

But that’s just the view of a spoiled reviewer. If I weren’t who I am (what a poet), I’d buy it with a clear conscience. If only for that satisfying lock sound.

Photo credits:

• studio photos — Hodinky 365 photographers
• screenshots — Coros app