Reviewed: Polar Grit X Smartwatch

A trailrunner’s dream and a great option for triathletes looking for a slim training smartwatch without spending a fortune.


Multisport touchscreen training smartwatch with built-in running power, some coaching, strength workouts, and way more


One of the most comprehensive multisport training watches we’ve ever seen, with more functions and abilities than a computer


Lots of these specific functions favor trail runners (though it has everything a triathlete would need), and no music or contactless payments may be a turnoff for some.





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Polar has been in the heart rate game for a very very long time. In fact, their heart rate monitors set the bar (and still do) for accuracy and analytics. Unfortunately, Polar had fallen behind the times with their watches in the past 10 years, as GPS smartwatches became the name of the game. In the last year, Polar has all but reversed that course with their overpacked Vantage V smartwatch, and their absolute category killer, the Vantage M. Both are light years ahead of what Polar had before, and are finally bringing back some lustre to their name. With the introduction of the Grit X, Polar has taken square aim at watches like Garmin’s Fenix series, that have become the gold standard for outdoor/trail-running/multisport watches that have everything on board. In response to brands like Suunto and their Suunto 7 that have gone a little more lifestyle than sport, Polar has done the opposite and packed a ton of super high-end training features into a light and slim package that is more useful in the gym than in the office. 

Polar Grit X Review: The Features

There is a lot going on with this watch, and in a few weeks of using this watch almost daily, I feel like I’ve only scratched the surface. But let’s start with the functions that triathletes care about and move down from there:

  • Open-water, pool swimming, cycling, indoor cycling, running, triathlon, and multisport modes 
  • Built-in running power
  • FuelWise to estimate how much fuel you’ll need during your session
  • Strong post-workout analysis
  • Seven days of battery in smartwatch mode with heart-rate monitoring and 40 hours in GPS/heart rate training modes
  • Recovery functions based on heart rate, previous workouts, and more
  • Weather forecast “mini-app” 
  • Coaching/workout suggestions
  • Syncs up to services like Strava, TrainingPeaks, MyFitnessPal and more 
  • Polar’s own Flow app acts like the Garmin Connect app with fairly similar features.
  • “Hill Splitter” feature gives stats on uphills/downhills
  • Route guidance to help with navigation, but no maps
  • A touchscreen

Polar Grit X Review: The Good

If you’re a triathlete who spends a lot of time on the trails, the onboard power, route guidance, and Hill Splitter functions are right in your wheelhouse. While the Hill Splitter is cool, it’s not quite as powerful as the other aforementioned trail functions. That said, accuracy on everything in this package is good, but not top of the pile: GPS is decent, on-wrist heart rate is about as good as optical heart rate can get, and running power is relatively consistent for everything but super short, super strong efforts. Polar’s app, Flow, is fortunately a high point that works as well, if not better than Garmin’s Connect or the Suunto app. Though it takes a little while to get used to, Flow has a very powerful post-workout analysis and ability to create workouts.

It’s almost unfair to compare the Grit X to something like Garmin’s Fenix series because the lowest-end Fenix 6 is almost $200 more, but the Grit X actually punches into that weight class. While we’ll have a Fenix 6S v. Grit X head-to-head in the next few weeks, the TL;DR is that most of the $600 Fenix 6S’ features are really not super important to triathletes who mostly swim, bike, and run. When you compare the Grit X to the Forerunner 645 in the same price range at $400, while the 645 does fine, it feels a little more utilitarian and unpolished when compared to the refined built-in features in the Polar. While the Garmin might feel a little more expandable and customizable with more flexible sport modes and apps, when really pinpointing what triathletes want, the Polar is ready-made for the multisport athlete without a lot of fooling around. Suunto’s 7 is far more lifestyle than the Polar, and the Coros Apex is a strong contender, but also feels a little less finished than the Grit X.

Finally, the big sell on this watch is its ability to do everything all in one place: You don’t need a foot pod, you don’t need a heart-rate strap, you don’t need a smartphone to help with guidance, it’ll even help with nutrition estimation and reminders. The Grit X goes a long way to reducing the amount of gear and guesswork when you go out for a workout, and that’s always been important to me when looking at new tech. Does this make my tri-life easier? Yes, for sure.

Polar Grit X Review: The “Ok”

While this is a great watch for triathletes and especially those who like to hit the trails, it’s not perfect. First off, in a time where most smartwatches do music and contactless payments, Polar’s watches are still much more training focused than lifestyle as they’re missing both. While it does a great job of showing smartphone notifications via a Bluetooth connection (which has gotten vastly better than when we reviewed the Vantage M and V last year), it’s still not a do-everything smartwatch like some of Garmin’s and Suunto’s offerings. Similarly, some of the really cool features on the Grit X like FuelSmart and the preloaded workout options are fun, but they can’t replace a real nutritionist or coach—these are just a best guess based on history and some good math. Still better than nothing, but it’s important not to treat the watch’s advice as gospel.

There are also a few small details—like the clunky “multisport” function that forces you to select a sport, hit start, then hit stop and select, find, and start the next sport between transitions. The triathlon mode works great for race day, but if you’re doing a repeating brick, a duathlon, or a swimrun event, you’re kind of stuck scrolling and stopping and starting when you go from leg to leg. 

The only other little good news/bad news feature on this watch is that there’s not a ton that you can do—in terms of workout set up or sport set up—from the watch itself. Some people may appreciate the fact that the Grit X’s interface is quite simple, allowing quick navigation and use, but others may feel frustrated by the inability to edit sport modes, data screens, and create workouts on the fly. You need to use the app for a lot on the Grit X. That said, the app is pretty good, but you just need to make sure everything is set up before you head out the door. Also, the watch’s basic interval/countdown timer setup is slightly clunky and buggy.

Polar Grit X Review: Conclusions, Go!

If you’re a triathlete who does even 50% of your training on trails—and you know that running with power is super key for trail runs—then this is probably the best option for triathletes who want a powerful, helpful watch to work out with. If you’re never on the trails and maybe you don’t live in a super hilly area, there’s almost no reason to get this watch—particularly since you wouldn’t really need running with power without trails or tons of hills. On the other hand, the Grit X has a small profile, a reasonably accurate on-wrist heart-rate monitor, decent GPS accuracy, and some really cool functions that help with everything from fueling to strength training. None of which can fully replace a coach, but with a healthy dose of realistic expectations, the Grit X can serve as a helpful resource that doesn’t require a monthly fee. As someone who doesn’t listen to music, use contactless payments, and does run a lot on hilly trails, this watch will probably replace my old favorite watch that cost almost twice as much. And this is the point: For $400 you’re getting a lot of high-end functions that you’ll often find in that “costs-as-much-as-a-nice-laptop” level of smartwatch in the $600-700 range. Again, as long as you’re realistic about what you do and don’t do with your smartwatch, the Grit X is an incredible value and may even take some of your other devices out of commission—an admirable function in simplifying your training. 

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