Garmin Fenix 5S review

Hey, guess what? The Garmin Fenix 5S is a GPS multisport watch that's neither massive nor ugly. You'd think that's a weird thing to celebrate, but it's quite the accomplishment in this category. In fact, launched alongside the flagship Fenix 5 and the map-tastic, fully-loaded Fenix 5X, the 5S is angled as those who like something a bit smaller on their wrist, with women in particular in mind.

That the watch is also meant to be a day-to-day fitness tracker, on top of being a world-beating outdoor watch, no doubt gave Garmin another reason to make something a bit more wearable. It still measures 42mm, so it's hardly dainty, but it's a watch you're much less likely to take off after a run.

The verdicts: Garmin Fenix 5 review | Garmin Fenix 5X review

It's basically just the Fenix 5 shrunk down into a slightly smaller package though, meaning you'll get all of the same features as the middle sibling, but not the advanced mapping of the 5X. This is still designed to be a fully-featured sports watch, whether it's running, cycling, swimming or snow sports you're after, offering the types of in-depth data we've come to expect from Garmin's top-shelf Fenix range.

Multisport fans should check out the incoming Garmin Vivoactive 3, but how does the 5S fare by comparison? Let's dig in.

Garmin 5S: Design and comfort

The key differentiator from the Fenix 5 (and 5X) is size. The 5S measures 42mm, making it the smallest of the range and more accommodating for slender wrists. Obviously this is Garmin's way of targeting the female market, but the 5S isn't being explicitly sold as a "girl's watch", and as a male with small wrists, I've found it a great fit. It's also worth remembering that the Fenix 5 is 47mm, which is bigger than average for a men's watch anyway.

But no, 42mm isn't very small (in Apple Watch terms, that's the size of the larger model) and the lugs alone take up a fair chunk of space. But what I love about the 5S is that I never have a need to take it off; it's a comfortable watch, and outside of running serves as a capable step tracker and notification device, with an always-on display that makes it perfectly adept as a time teller. I also lent it to a female friend for a couple of days, and she remarked how comfortable it felt compared to her current running watch.

That said, the screen is 0.1 inch smaller than the one found on the Fenix 5, and has a resolution of 218 x 218, while the other two watches have been bumped up to 240 x 240. Garmin's focus is still on clarity and not beauty, and for a workout watch like this that's fine – especially when it keeps the battery working to its potential. I've found the 5S to be really easy to read in different lighting conditions, and it's got a backlight for using in the dark. Oh, and in case the pictures don't make it obvious, it's a colour display. Like the 5, the 5S also comes in regular glass and sapphire variants.

Little 'n' large: Fenix 5S on the left, 5X on the right

The button setup is the same as the 5 here too, with two on the right side of the face for going forward and backwards through menus, and three down the left for scrolling up and down through options, and activating the backlight. It's taken me an unexpected amount of time to get to grips with the input system, and even now I still find myself tapping the wrong button every so often. It feels a bit of an unintuitive system to be honest, but you'll learn it soon enough.

The Fenix 5S comes with a silicon band that can be swapped out for different colours and materials, using Garmin's 'QuickFit' release mechanism. That means it's not a universal fitting; you'll need to choose specially made straps if you want to mix up your look.

Garmin Fenix 5S: Features

The 5S does a lot. From running to cycling to water sports and skiing – and everything in between – this watch is equipped to tackle a wide range of activities. And if it's not on the list, you can just make it yourself, either in the app or by typing it out on the watch letter by letter (yeah, a bit of a pain, but once it's saved, it's saved).

Starting a workout is as simple as tapping the top right button once and then scrolling to your designated activity. You can choose which activities you want quick access to, and as I mentioned, you can just make your own. There's an impressive amount of granularity when making a custom activity, as Garmin lets you add custom alerts, auto lapping, 3D distance, auto pause, metronome, and what type of data you want displayed during – among other things.

You can change the settings of pre-set activities with all of the above options by going into the watch menu and scrolling along to Activities & Apps. You can also view your history of activities, diving into all the juicy metrics. I particularly like that I can see an aerobic vs anaerobic breakdown of each activity.

I've primarily been using the 5S for running, which is what a lot of buyers will be focusing on, and for that you've got a wealth of information at your fingertips. For the more serious trainers, you'll find VO2 Max – a stat that's becoming all the rage in fitness tech – as well as recommended recovery time, and a Training Load feature that tells you whether the amount of training you've been doing over the past week has been the right amount, too little or too much. You can view these stats via widgets, which are easy-to-access screens you can scroll through, plus there are plenty of downloadable custom watch faces too, displaying various metrics at all times.

The Fenix 5 also serves as a daily activity and sleep tracker. This is something Garmin has angled more at with the Vivosmart 3, but the 5S will track your daily steps, calories burned, floors climbed and hours slept. You can also see your heart rate throughout the day. Over my time using the 5S I've noticed my resting bpm is on average 5 bpm lower than the Fitbit Alta HR reports, which I find a bit curious as when I look at them both side by side, the 5S is usually a fair jump higher in that moment. I assume various algorithms are at work to keep this in check.

Outside of fitness and activity tracking, Garmin has also packed in some limited smart features. The big one is notifications, and you'll be able to get texts, calls, WhatsApps, email updates and more on the watch. However, the handling of notifications is very basic, and you can't interact with them in any way on the watch.

Garmin Fenix 5S: Heart rate and GPS performance

The Fenix 5S includes the same optical heart rate monitor found on the other two in the range, but you can also pair it with a chest strap if you like. I tested it alongside the Polar H7 strap, but I did get prompts on the watch asking me if I wanted to connect the two together when it was workout time.

Every time I've taken the 5S on a run, GPS locking has happening in a matter of seconds. Now, I do a lot of street running, and there are some tall buildings in my neighbourhood, which is likely the reason why on some runs it showed me running through the odd block rather than sticking to the roads – which I believe is the Hulk's preferred form of travel. However, generally it had no problem following my route, and as soon as I got into more open streets it improved. I put it up against the Polar M200, my Pixel smartphone and of course my own memory of my route, and I've found the Fenix 5 to be solid in the GPS department, particularly impressing with its speed in locking on.

Fenix 5S on top, Polar H7 strap bottom

Now for heart rate – the ever tricky one. I'm in a regular running routine at the moment where I'm hitting a few 5ks a week, with a few bouts of interval training, so I want a watch that can keep up with those high-intensity peaks. I've been putting the Fenix 5S up against the Polar H7 chest strap, which we consider one of the "gold standard" straps right now. And for more consistent running, it's proved to be solid.

During a run with more intervals however, the watch didn't fare quite as well, struggling a bit to map the fluctuations, but my average heart rate came out spot-on with the chest strap, and only 1 bpm higher on max HR. During my first sprint at the five-minute mark it read my heart as dropping. As James found in his review of the Fenix 5, it took the watch up to 10 minutes to hone in on the chest strap reading, so I guess that this was the case here. You can also see in the graph above that it was bouncing a little at the start.

Comparing intervals (Fenix 5S below, Polar H7 strap above)

I haven't yet been able to test the 5S for cycling, but for running it's served me well. As I said, when the HIIT kicks in it doesn't live up to the chest strap, but overall I've been impressed with what Garmin's managed with its Elevate sensor here.

Garmin Fenix 5S: App and battery life

My biggest problem with the 5S isn't really to do with the 5S itself, but with Garmin's app; it's desperately in need of an overhaul. It's not that it's lacking features, but finding your way between them is more hassle than it needs to be. Generally, it's not the most intuitive software and never feels like a pleasure to use. It's also prone to freezing and sometimes outright crashing. In fact, I find it incredibly sluggish on my Pixel.

You can push your workout data to other apps such as Strava, but bear in mind that you'll lose out on viewing some of the deeper metrics like Training Effect in the third-party apps, so it really depends on how "hardcore" a runner you are. If you want to build your own workouts you'll need to do that with the Connect Portal, which can be accessed on a browser or desktop app. Once you make a workout you can choose to send it to your device, and it will show up under the workouts section of the smartphone app.

A smaller shape does also mean a smaller battery life than the other two Fenix 5 watches sadly, but Garmin says to expect nine days in smartwatch mode and 14 hours in GPS. Balancing the two, as I have been, I've managed to get around 6-7 days of power from the 5S, which is good, even if it's the least of the Fenix family.