The Garmin Fenix 6 is arguably the best outdoor sports watch you can buy right now, but the Polar Grit X will give the Fenix a run for its money on price, features and battery life.
Both outdoor watches promise the kind of features that should appeal to trail runners, hikers and general lovers of the outdoors. Both incorporate mapping, navigation, big battery life and rugged, durable designs – with a focus on the toll of clocking up long distances.
We've spent a fair amount of time with both watches now to get a good sense of how the Polar Grit X stacks up with the Fenix 6 and vice versa.
So if you're weighing up whether to choose between the two, we've highlighted the biggest differences to help you get a better sense of which outdoor companion might be the better fit for you. And make sure you read our review of the new Polar Grit X Pro too.
Polar Grit X v Garmin Fenix 6: Design
Let's cover the basics first. The Polar Grit X is available in just one size. That's a 47mm case with either a small or medium/large wristband.
For the Fenix 6, well, you've got a fair few more options to choose from. It's available with a 42mm, 47mm or 51mm case. Then you've got the option of going Pro on all models to add mapping and music features. Make it a Sapphire edition too and you'll add an extra layer of screen protection.
Both offer stainless steel cases and polymer rear covers, though the Fenix is also available with a titanium case option too to make it lighter to wear.
At 64g, the Grit X is the lighter of the watches if you compare to the similarly sized Fenix 6 (83g for stainless steel, 72g for titanium) and those small differences in weight may be a bigger deal over longer runs, rides and hikes.
They match for waterproof ratings making them fit for pool and open water swimming up to 100 metres depth.
In terms of navigating the watches, the Fenix sticks to a button-only setup while the Grit X opts for both touchscreen and physical buttons. Based on our experience though, the responsiveness and quality of the touchscreen isn't great and will force you to use the buttons more.
The displays give you around the same as far as quality and visibility. You've got backlights on both to illuminate things when you're at night. These are both always-on displays if that's a big deal for you.
The watch straps that keep these cases in place we can't really have complaints about. You're getting a silicone strap that hasn't cause any irritations or discomfort in our time with them.
We'd be inclined to say the slightly smarter exterior of the Grit X strap is nicer to look at. Ultimately though, these straps do the job of holding up in a workout. Both are interchangeable too if you want to go with something nicer.
If you care about looks, we'd be inclined to say the Fenix 6 offers a bit more in the way of character. There's nothing inherently wrong with the Grit X's design, but it definitely feels more like a running watch than an outdoor watch.
Polar Grit X v Garmin Fenix 6: Outdoor features
This is obviously a big one. What do these watches bring to the table when it's time to step out of the confines of your gym or local running route?
Let's start with the Grit X and mapping, which offers route guidance with real-time guidance and route planning using third party app Komoot. Garmin also offers point-to-point navigation, real-time breadcrumb trails. You also get preloaded topographic maps, ski resort maps and fair few more features in the way of mapping.
Garmin's has mapping features on its own platform, and watches with the Courses waypoint navigation feature (including Fenix) can now sync with services such as Strava and Komoot for route uploading. Strava will create routes free, and a paid subscription will add things like Live Segments.
Polar does require you using Komoot for route planning, which does require a paid subscription to get the most out of it. In terms of that navigating experience, it's bit more of a simplistic affair on the Grit X, with the Fenix offering much richer TOPO maps to view on the watch.
Another headline outdoor feature for the Grit X is Hill Splitter, which offers data on the downhill and uphill sections of your workout session. Garmin does have something similar in the way of its ClimbPro features. This allows you to see real-time data on current and upcoming climbs.
Our time with Hill Splitter has thrown up some mixed results, though it's nice to see both offer a feature that will no doubt appeal to trail and ultra runners or those tackling those weekly hill training sessions.
If you're planning to spend hours and maybe days out tracking making sure you keep on top of your fuelling is something you'll no doubt care about.
Polar's new FuelWise feature is designed to do that offering smart reminders based on workout duration and heart rate to help determine when it's time to eat again. It also offer the ability to set drink reminders too all with the goal of keeping you well fuelled.
In our review of the Polar Grit X the nutrition planning was a huge success, and a massive reason for ultra runners and endurance hikers to opt for the Grit X. However, we did find alerts too easy to miss – and this feature could be easily improved.
Garmin doesn't really offer something that works in a similar way. It does offer hydration tracking, but it's a feature designed more about daily water intake as opposed to fuelling.
Polar Grit X v Garmin Fenix 6: Sports tracking
Garmin and Polar know how to do sports tracking and that doesn't change with the Grit X and the Fenix 6. You're getting plentiful sports modes for indoors and outdoors, all the key sensors like an altimeter and compass and a raft of basic and advanced metrics.
Polar promises over 130 sports profiles and for outdoor folk, you're getting dedicated modes for the likes of hiking, trail running, ultra running, trekking, snowboarding and mountain biking. Flip that over to Garmin and the Fenix is well stocked with outdoor sports modes. The likes of hiking, climbing, mountain biking, skiing, cross country skiing and even kayaking is covered. We'd say Garmin just edges it for having a few more dedicated outdoor sports modes.
You're also getting plenty in the way of training and analysis insights if you want to dig deeper into your performance. Garmin looks to Firstbeat and its heart-based analytics software to bring in features like Training Status, Load and Training Effect.
Guide: Train better with Polar Flow
The Grit X makes use of its Training Load and Benefit insights to give you a better sense of your workouts and make sure you're not training too hard. It does however miss out on the usual Training Recovery Pro feature that was available on Polar's Vantage V watch.
How do the sets of features compare? These insights feel a bit better displayed on the Fenix than they do on the Polar. Though Polar's web app does a better job of letting you pore over the data on a larger screen. Ultimately what underpins the usefulness of these training features is the reliability of the heart rate sensor, which can be mixed on both watches outside of pairing an external heart rate monitor chest strap.
Those key sensors like GPS and heart rate monitor are pretty much on par based on our experience. The Grit X felt a bit quicker to lock onto a GPS signal, but the Fenix 6 wasn't too far off it in general. If you care about data fields, you're getting a few more that can be displayed on a single screen on the Fenix than you can on the Grit X.
You do have those additional power data screens to scroll through on the Polar as the Grit X measures running power from the wrist just like the Polar Vantage V series.
For the heart rate sensors, it's definitely a good thing that both offer the ability to pair external chest straps. The Fenix offers Bluetooth and ANT+ connectivity with the Grit X lacking the latter. What you get in the way of performance is something that's suitable for most workouts, but we still found some issues at high intensity training.
The Polar also delivered randomly high spikes from its Precision Prime sensor tech. The reliability of those onboard heart rate monitor sensors has a big say on the usefulness of the additional features like training and recovery insights. If you want the best results and more valuable data, grab a chest strap.
Bottom line, both offer solid sports tracking experiences that are not without their issues. You can track a lot and see a mass of data, albeit it's all quite overwhelming to review it all in the respective companion phone and web apps.
Polar Grit X v Garmin Fenix 6: Smartwatch features
When you're not climbing mountains or tearing up the treadmill, how do these watches compare? We are going to break this down into all-day fitness tracking and those smartwatch skills.
For fitness tracking, those features feel far more prominent on the Garmin than they do on the Polar. You're getting step tracking, sleep monitoring and continuous heart rate monitoring on both.
We found the Grit X's step tracking quite excessive, though the Sleep Plus Stages and insights were far more useful. Though it does take some time getting to grips what it all means. Polar also includes the Nightly Recharge feature it introduced on its Ignite watch. This moves into looking at how well recovered you are from your day by harvesting more data from your sleep.
It takes sleep quality data and combining insights with how your automatic automatic nervous system (ANS) has calmed down giving you a score based that recharge status. It's a concept that feels quite complex to get to grips with that's hugely reliant on sleep monitoring been spot on. What we found was the Grit X was generally more in line with Withings' dedicated Sleep tracker for registering core sleep data like duration and breakdown.
The Garmin on the other hand tended to be a little less accurate for sleep, particularly putting us asleep at times an hour before we actually nodded off. Garmin does also include additional insights from the onboard pulse oximeter and respiration via the heart rate monitor. Though there's not a lot in the way of offering some insights behind that data. If you want something that tries to better correlate sleep with your exercise, the Polar does a better job of it.
As smartwatches, there's no real contest. The Grit X keeps to the basics letting you view notifications and offers regular weather updates.
The Fenix 6 gives you notifications, payments, music features and access to the Connect IQ Store to download apps, watch faces and more. While the Grit X plays nice with apps like Strava and TrainingPeaks, it doesn't have any form of app store. You get what's on the watch and that's your lot.
If you want something that strikes a better balance between smartwatch and sports watch, go for the Fenix.
And finally, Fenix 6 Pro watches offer the ability to listen to music from the wrist - including syncing Spotify playlists. That's a pretty big deal for some people, and makes the Fenix 6 a powerful smartwatch choice.
Polar Grit X v Garmin Fenix 6: Battery life
If you're planning to spend a lot of time away from home exploring, having an outdoor watch with sizeable battery life is pretty much a necessity. Thankfully, both of these watches have a lot in the way of battery.
The Grit X promises 40 hours in training mode with GPS and heart rate monitoring in use. You're touted seven days in smartwatch mode, though we tended to get 4-5 days. If you switch off continuous heart rate monitoring, it should go longer. For workouts, it retains that battery well and there's power saving modes for various sports that reduce the GPS sampling rate to get you significantly longer during tracking.
The Fenix 6 promises 36 hours with GPS tracking and 2 weeks in smartwatch mode. There's also a maximum GPS mode of 72 hours and an Expedition mode that keeps you tracking for up to 28 days. Garmin also includes it battery saver watch mode, which it says will get you up to 48 days.
What we've found is that both hold their battery well during tracking, though there's a bit more of a noticeable drop off during the time outside of tracking on the Grit X.
The Garmin seems to cope better at those lower levels of battery charge, giving you a little extra time to track before it's time to grab that charger.
Polar Grit X v Garmin Fenix 6: Price
There's a significant price difference between the Fenix and the Grit X. Even if you go for the cheapest Fenix option. That's the 6S without going Pro to add maps and music features or adding a Sapphire crystal lens to bump up protection. That comes in at .
There is only one version of the Grit X and that's priced at . So that's quite a sizeable jump up going from Grit to Fenix.
If you care about picking up additional official watch bands for either watches, there's cheaper options available for the Grit X. You do have your pick of silicone, woven and leather bands with the latter option proving to the be priciest.
Polar Grit X v Garmin Fenix 6: Verdict
So, do you go Fenix 6 or Grit X? There's really a couple of ways to look at this. If you want the one that should give you the best outdoor watch experience, our feeling would be to say the Fenix 6. Core features like mapping feel a bit better executed than it is on the Grit X. You do still get big battery life and plenty of more outdoor-focused metrics to delve into. The design for us just gives it the feel of a nicer looking watch to hit the trails with too.
If you want something that's a good mix of sports watch and smartwatch features, it's the Fenix 6 that gets out our vote too. Simply for the fact there are more smarts on board and you similarly get a wealth of sports modes like you do on the Polar.
The Grit X's FuelWise is certainly a nice addition and definitely something that Polar has over on Garmin in terms of thinking more about fuelling and hydration during long exercise sessions.
It's important to keep the price in mind here too. Even the cheapest Fenix 6 is still more expensive than the Grit X. There's not a great deal of great outdoor watch options at the same price as the Grit X. You could also probably look at something like the Coros Apex, but you'd miss out on some of the richer training features you'll find on the Grit X. It's a decent watch, though the Fenix 6 will give you more if you're willing to spend more.