Garmin Fenix 5X Plus review

As is tradition with the Garmin Fenix cycle, we don't expect we'll see the Garmin Fenix 6 until 2019. So for this year, Garmin is refreshing its trio of Fenix sports watches, with the Garmin Fenix 5X Plus topping out the range.

Yes, it's called the Plus because it's the 5X – plus a bit more. Until now, the 5X has been Garmin's most serious adventuring watch, packed to the gills with sports and outdoor features; you'd be hard pushed to find an activity it can't track.

Wareable verdict: Garmin Fenix 6X review

With the 5X Plus, Garmin is throwing in some smart features that give it parity with some of its other sports watches – Garmin Pay, music support – but doesn't improve matters as dramatically as the 5 Plus and 5S Plus, which also get the topographic map support that was previously only available on the Fenix 5X.

The 5X still supports an impressive range of activities, and the same top-of-the-shelf features, but there are a couple of new tools, like a pulse oximeter, that will certainly appeal to outdoor adventurers.

We've been living with the Fenix 5X Plus for a little while now – so here's our verdict on Garmin's latest outdoor sports watch.

Garmin Fenix 5X Plus: Design

The 5X was a wrist colossus and the Plus is no more agreeable. Measuring 51mm across and 17.5mm thick, this remains unbeaten in size amidst Garmin's collection of sports watches. As someone who doesn't have the colossal wrists to match, this is a watch I very much notice I'm wearing, especially as it weighs 96g. It's heavy, which is particularly a problem when running as the watch moves around a lot, usually requiring me to tighten it more than I'd like.

Wareable verdict: Garmin Fenix 5 Plus review | Garmin Fenix 5S Plus review

Garmin's still embracing the industrial look, with those five face screws as proudly visible as ever. Everything here looks pretty much the same as the Fenix 5X. You've still got that 240 x 240 resolution display, and there are the same five buttons around the outside. Remember that unlike Garmin's other sports watches, the Fenix line doesn't make use of touchscreens, so they require more buttons for navigating.

On the back the 5X Plus emits the same three green lights, but this time with a new red light, which is the pulse oximeter for keeping an eye on blood oxygen saturation. We'll come to that in more detail in a bit.

With the improvements to design we're seeing in Garmin's other ranges, most notably the recent Vivoactive 3 Music, we expect the Fenix 6 range will get a cosmetic facelift. After all, with smart features like pay and music, Garmin's presenting these as all-day wear, so they need to look the part. The 5X Plus is proudly rugged and ready for the great outdoors, but it's still probably not a smartwatch you'll want to keep wearing once you're back at the foot of the mountain.

Garmin Fenix 5X Plus: Sports tracking and mapping features

If the Fenix 5X Plus can't track it, you probably shouldn't be doing it. Garmin's Fenix range is exhaustive in its ability to track outdoors sports and activities – running, cycling, golfing, kayaking, stand-up paddle boarding, biking, skiing, yoga. That's just to name a few. There's even a pre-set activity for boating that will track your nautical speed. And if you somehow don't see your desired activity on there (seriously, what the hell are you doing?) you can make a custom one.

The Fenix 5S Plus offers the same package of sports and fitness features you'll find in the Fenix 5X, with the addition of pulse ox acclimation. Last year, the big reason to have chosen the 5X over the 5 or the 5S (the smaller of the range) was for topographical mapping, but the Plus range now brings maps to all the watches, meaning the 5X has less of an upper hand. The 5X Plus comes pre-installed with a Worldwide DEM Basemap, which displays information on major roads, cities etc, and topographical maps, which provide more details including contour lines.

Together they form a rich amount of data that hikers will be able to use to get a good sense of their location and nearby routes, aided by GPS, GLONASS and, new with the Plus watches, Galileo satellite tracking. This lineup makes the watch sturdier when tracking in more demanding environments, rather than relying on GPS alone.

We took this out for a hike ourselves and found the experience to be much as we found it on the 5X. In terms of tracking, you can either start a hike from the activity list or simply selection the 'Track me' option, which will just keep an eye on your time and distance. In fact, the mapping came in handy during one stretch where we were unsure about taking a slightly dicey looking path (and our phone was totally out of signal). A glance at the watch confirmed this would have been a bad idea, leading to a dead end, and offered us a safer alternative. When looking at the map, a long push of the menu button (middle left) will offer up the option to pan and zoom the map, should you want to explore more of the area or find yourself squinting to read it. After all, you're looking at an entire map on a watch here.

With the 5X Plus you can build a course right from the watch, which you can do by setting a point on the map or choosing a point of interest. For runners and cyclists, you can also set a round-trip course, specifying distance and direction, and the watch will crunch the numbers and mark out a route it thinks would be appropriate.

You can also use the map features to search for points of interest, although this feature isn't the easiest thing to use on the watch, and something you're probably only going to use if you have no phone service and find yourself lost in the wilderness, in need of lodging. If you're looking for entertainment, a services the 5X Plus provides, chances are you're better off just pulling out your phone. Or hey, maybe ask a local?

GPS accuracy in hiking has been mostly good, although certainly not perfect. You can see on the map above, to the far right, how it struggled with that corner and thought I was walking through the bushes. Oddly I was testing the Fenix 5S on the same trail and that proved to be a little more accurate in this instance.

As for running and heart rate accuracy, performance was on par with other Fenix 5 watches when tested with the trusty Polar H10 chest strap: good for the most part, but during more intense bursts the 5X Plus was lagging behind, taking longer to hit the highs and climb back down again. As you can see in the graph below, this meant the peaks and troughs were out by 5-7 BPM at times. It also made for some quite jittery lines.

The weight of the watch is also a problem during running, sometimes making it feel like it's making a bid for freedom, so you'll need to keep it nice and tight to ensure the heart rate readings are as accurate as possible.

Garmin Fenix 5X Plus (top) vs Polar H10 chest strap (bottom)

Finally, it's worth adding that the Fenix 5X Plus also ticks off the fitness tracking basics like step count, calorie burn, floors climbed and all-day heart rate. There's also sleep tracking, which has just been bolstered by Garmin's advanced sleep tracking and stages insights, something Fitbit has been offering for a while. You'll now see something like this:

Garmin's now giving you a more detailed breakdown into deep, light and REM sleep. You can also see a graph of your movement through the night. Overall we've found the sleep tracking to be more accurate, which is great, but chances are you're not going to want to wear a watch this size to bed…

What is pulse ox acclimation?

The big new feature on the Garmin 5X Plus, not found on the other Plus watches, is what Garmin refers to as "pulse ox acclimation". Put simply, Garmin is using a pulse oximeter to take a measurement of your blood oxygen saturation (how much haemoglobin is carrying oxygen). If you've seen us talking about SpO2 before, it's the same thing. Measuring blood oxygen saturation can reveal many helpful insights, but while Fitbit is interested in using it for conditions like sleep apnea, Garmin has put it in the Fenix 5X Plus so you can keep an eye your saturation when scaling higher altitudes. This is what the new red light on the back of the 5X Plus is checking for.

Read this: Your running watch stats explained

Your saturation will be displayed as a percentage; the higher the number shown on the screen, the better. Most people need this saturation level to be at least 89% to stay healthy, and at sea level the human body operates to its best potential. But at higher altitudes the amount of oxygen in the air decreases, which can have an effect on someone's SpO2. The pulse ox acclimation feature is a way to see how your body is adjusting to higher altitudes by monitoring your blood oxygen levels.

We haven't been able to scale any great mountains with the 5X Plus yet, but we did take it out hiking on some hills to see what would happen. The Pulse oximeter displays as one of the widgets from the home screen, which can be scrolled to using the buttons on the left hand side. It can be set to take readings automatically or manually but – and here's the thing – it requires you to be incredibly still in order to get a read. This is because any slight movements can interfere with the sensor. That means there's a lot of holding your wrist out and "Doing the Biff" as you wait for a verdict. This is standard fare for using this technology, but a problem when you choose to have the watch take acclimation readings automatically, as when we checked there were large gaps between readings, presumably because we hadn't been still long enough at any point.

You can't add oxygen saturation to your data screens, so to see it while tracking an activity you'll need to have a hot key assigned to take you to your widgets. We were slightly concerned to see our saturation drop to 80% when we were up no higher than 300 feet, which seemed quite dramatic for that amount of elevation, but otherwise it's been steady around 98%. We're going to keep a close eye on this and continue to test it, and we'll update this review once we've spent some more time with this feature.

Garmin Fenix 5X Plus: Smartwatch features

The Plus is also getting new features to use when you're not scaling great heights: music and Garmin Pay.

Garmin has been gradually adding music support to its sports watches, starting with the Forerunner 645 Music and more recently the Vivoactive 3 Music. That's now coming to the entire Fenix Plus line, letting you load music onto the watch and listen through Bluetooth headphones. As with the Vivoactive 3 Music there's enough room to sync around 500 songs, which can be uploaded using the desktop Garmin Express drag-n-drop method. Garmin also has support for iHeartRadio subscribers, letting users sync their playlists offline to the watch, while Deezer support is still incoming. No Spotify here, sadly.

Music can be accessed directly from the widget, but it can also be assigned to a hot key for when you're in the middle of an activity. Playback controls are pretty good on the watch, letting you pause, skip, shuffle, repeat and adjust the volume. You'll even see a little icon with the album art, and if you're streaming through your paired smartphone instead, you can choose to control the phone playback from the watch.

Garmin Pay, Garmin's smartwatch payment platform, is also now on the Fenix Plus line, meaning you can head out of the house and still buy that post-workout bottle of water – as long as the store supports NFC. This feature wasn't available to try at the time of review, but we'll be updating this once we've been able to test it to see if the experience is any different here.

Another thing we haven't yet been able to try is phone notifications, but the story hasn't changed much here. You'll be able to see notifications like texts and calls pop up on the watch, but this functionality isn't as good as you'll find on, say, the Apple Watch, especially if you're using an iPhone. If you're paired with an Android phone you can send canned quick replies from the watch.

Garmin Fenix 5X Plus: Battery life

Finally, battery life. Garmin's improved things here on the Plus, moving from an expected 20 hours of tracking with GPS on to 33 hours, and now 20 days in smartwatch mode compared to the 5X's 12 days. That's quite a leap up, and it'll be a welcome one for hikers who were disappointed by the 5X's inferior battery to the Fenix 5, despite it offering more for adventurers. Of course, there are now even more factors that can affect these numbers. Streaming music, for one thing, will diminish the battery faster, as will taking acclimation readings all through the day.