Polar Grit X vs Garmin Fenix 6 Pro

Polar Grit X vs Garmin Fenix 6 Pro

The Polar Grit X is a versatile multisport GPS watch built to compete with the likes of the Garmin Fenix 6 and the Coros Vertix. It’s basically a Polar Vantage V, with a more rugged design and military grade durability. 

The Fenix 6 Pro is arguably the best watch in Garmin’s product line-up, if looking at the combination of price, value and features. It also boasts triathlon capabilities and military grade construction. But, unlike the Polar Grit X which is primarily a sports watch, the Fenix 6 also boasts powerful smart watch technology and impressive navigation capabilities. 

The goal of this post is to help you decide which watch is better suited to your needs. Now let’s dive into the details. 

Side note – We also have a complete review of the Polar Grit X here.

Table of Contents

Summary of main differences between the Polar Grit X and the Garmin Fenix 6 Pro

  1. The Polar Grit X Is Much Lighter: To be more specific, the Grit X is 64 grams, whereas the Fenix 6 Pro is 93 grams. 
  2. The Grit X Supports Running Power from the Wrist: No Garmin product currently offers this feature. You need to purchase a Garmin accessory to unlock native running power on the Fenix 6 Pro. 
  3. Advanced Running Dynamics: The Garmin Fenix 6 Pro gives you access to 6 advanced running stats, including real time cadence and vertical oscillation. 
  4. Proper Golf Mode: The Grit X has a basic golf mode. The Fenix 6 Pro has super advanced golf tracking technology. 
  5. Music Storage: The Fenix 6 Pro can store up to 2000 songs and it’s compatible with popular music apps. The Polar Grit X doesn’t have music storage capabilities. 
  6. ANT+ Connectivity: The Fenix 6 Pro is compatible with a lot more cycling accessories because it offers support for ANT+ connectivity, which lots of these accessories depend on to work properly. 
  7. Powerful Navigation Capabilities: The Fenix 6 Pro has built-in navigation technology that is similar to what you would find in one of Garmin’s vehicle GPS units. The Polar Grit X has some navigation features, but they’re not comparable to the TOPO maps found in the Fenix 6 Pro. 
  8. Super Long Battery Life Modes: The longest GPS battery mode on the Fenix 6 Pro is 46 days! Fortunately, the Polar Grit X has a great standard GPS battery life (40 hours) and the ability to extend that to 100 hours. Most people will be perfectly served by both watches in terms of battery life. 
  9. Touchscreen – The Polar Grit X has a touchscreen + button interface. The Fenix 6 relies exclusively on buttons. 

Side note – It’s worth mentioning that there are quite a few variations of the Garmin Fenix 6. This comparison chart explains the differences between the Fenix 6, the Fenix 6 Pro and the Fenix 6 Sapphire. 

Key Similarities - Polar Grit X vs Garmin Fenix 6 Pro

Polar Grit X

Fenix 6 Pro


Military Standard Durability

Wrist-based HRM

Activity Tracking

Sleep Tracking

Indoor + Outdoor Running

Indoor + Outdoor Cycling

Indoor + Outdoor Swimming

Indoor + Outdoor Rowing

More than 25 Sports Modes

Triathlon Mode


Accelerometer + Compass

Barometric Altimeter

Route Planning with Komoot

Turn-by-turn Route Guidance

Changeable Watch Straps

Native Running Power


With Accessory

3rd Party Running Power

Stryd + RunScribe

Stryd + RunScribe

Water Proof Rating



Key Differences - Polar Grit X vs Fenix 6 Pro

Polar Grit X

Fenix 6 Pro


Less Expensive

More Expensive


64 grams

93 grams

Screen Size

1.2" (30.4 mm) diameter

1.4” (35.56 mm) diameter

Screen Resolution

240 x 240 pixels

280 x 280 pixels


47 x 47 x 13 mm

51 x 51 x 14.9 mm

Total Sports Modes

130+ Sports/Activities

30 Sports/Activities

Smartwatch Capabilities



Built-in Running Power


Fuel (Food) Recommendations

Stress Monitoring

Pulse Oximeter

Music Storage & Apps

Payments from Watch


Golf Tracking with 41,000 Pre-loaded Courses

Ski Tracking with 2,000 Resort Maps

WiFi Connectivity

ANT+ Connectivity

Advanced Running Dynamics

Temperature + Altitude Acclimation

Power Management Options

Safety Tracking Technology

Smartwatch Battery

Up to 7 Days

Up to 21 Days

Standard GPS Battery

Up to 40 Hours

Up to 60 Hours

Extended GPS Battery

Up To 100 Hours

Up To 120 Hours

Comparison of Sports Modes

Polar Grit X Sports Modes Garmin Fenix 6 Pro Sports Modes
01) Strength Training 01) Strength Training
02) Circuit Training 02) Cardio Training
03) Cross Trainer 03) Elliptical Training
04) Indoor Climbing 04) Stair Stepping
05) Functional Training 05) Floor Climbing
06) Indoor Rowing 06) Indoor Rowing
07) Pilates 07) Pilates
08) Yoga 08) Yoga
09) Running 09) Running
10) Treadmill Running 10) Treadmill Running
11) Track and Field Running 11) Indoor Track Running
12) Trail Running 12) Trail Running
13) Hiking 13) Hiking
14) Orienteering 14) Climbing
15) Mountain Biking 15) Mountain Biking
16) Skiing 16) Skiing
16) Snowboarding 16) Snowboarding
17) XC Skiing 17) XC Skiing
18) Windsurfing 18) Stand Up Paddleboarding
19) Rowing 19) Rowing
20) Kayaking 20) Kayaking
21) Kitesurfing 21) Jumpmaster
22) Surfing 22) Tactical
23) Cycling 23) Cycling
24) Indoor Cycling 24) Indoor Cycling
25) Mountain Biking 25) Mountain Biking
26) Triathlon 26) Triathlon
27) Pool Swimming 27) Pool Swimming
28) Open Water Swimming 28) Open Water Swimming
29) Duathlon 29) Swimming/Running
30) Basic Golf Mode 30) Advanced Golf Mode
31) View All Grit X Sports Modes

Main Reasons To Choose the Polar Grit X

Running Power From The Wrist

Before the release of the Grit X, the Polar Vantage V was the only GPS watch to offer running power from the wrist. Now the Grit X can be added to that exclusive list. 

In our opinion, this was a great call from Polar. It helps to justify the selling price of the Grit X. It’s also a feature that Garmin users can only access by purchasing a compatible accessory.

Ultimately, the ability to record running power without any accessories is arguably the number one selling point of the Polar Grit X. It’s basically a better looking, more durable version of the Polar Vantage V.

Military Grade Construction

By introducing military grade construction to the Grit X, Polar are essentially taking their cues from the Garmin Instinct and the Garmin Fenix 6,which are both built in accordance with military standard. 

The primary benefit is that the Polar Grit X is literally the most durable GPS watch that Polar has ever made. It smashes the Polar Vantage V and the Vantage M in this respect.  

The Polar Grit X is much lighter than the Fenix 6 Pro

In most comparison articles we don’t really focus on the weight of the watch all that much. However, there is a substantial difference between the Polar Grit X and the Fenix 6 Pro in terms of weight. To be more precise: 

  • Polar Grit X Weight – 64 Grams
  • Garmin Fenix 6 Pro Weight – 93 Grams

As you can see, the Grit X is about 30% lighter than the Fenix 6. Lighter watches tend to be more comfortable during everyday use, and when exercising, so this is a small win for the Polar unit. 

130+ Sports Modes

If there’s one area where Polar is truly dominant in the world of sports watches, it’s the total number of supported sports modes. 

The Polar Grit X can literally go toe-to-toe with pretty much every sports mode that the Fenix 6 Pro has. And then it adds an extra 100 modes on top of that. 

  • Garmin Fenix 6 Pro Sports Modes – 30
  • Polar Grit X Sports Modes – 130 

You can see the full list of Polar Grit X sports modes here

More Advanced Sleep Tracking

Polar’s sleep tracking technology is a notch above Garmin’s. With the Fenix 6 Pro you get total sleep, periods of moment and periods of restful sleep. But by opting for the Grit X, you gain access to Polar’s Sleep Plus Stages Technology. The quote below explains this in greater detail: 

When you sleep, your body goes through sleep cycles that consist of three sleep stages: light, deep and REM sleep. Sleep Plus Stages shows how long you spent in each sleep stage and counts your sleep cycles.

FuelWise & Energy Sources

FuelWise In A Nutshell: When you’re doing a long training session or race, it’s crucial to maintain adequate energy and hydration levels. FuelWise™ is a smart fueling assistant that helps you find the optimal way to refuel your body during a longer session so you’ll be able to keep going and perform at your best (sourced from Polar.com). 

Energy Sources In A Nutshell: See how your body uses different energy sources during a training session. Polar Grit X divides your energy usage into carbs, proteins and fats (sourced from Polar.com). 

FuelWise and Energy Sources are new additions to Polar’s ecosystem. The main benefit is ultimately for ultra long distance runners and trail runners, who need to keep a close eye on physical energy levels to perform optimally on race day. It’s might not be relevant to all users, but if you participate in ultra marathons (on the road or on the trail), FuelWise could be helpful when training and racing. 

Hill Splitter

The whole point of hill splitter is to get detailed data about your performance on the uphill and downhill sections of your session. 

Right now, the Polar Grit X is the only watch in their line-up which includes this feature. The main benefit here is for trail runners and mountain bikers that tackle challenging vertical terrain. It’s nice info to have when you are training, and it’s also great for post run analysis. 

With that being said, Polar Hill Splitter is no match for the combination of Garmins PacePro, ClimbPro and Topo Map technology, which can all be leveraged to provide similar data, more conveniently. 

Main Reasons To Choose the Garmin Fenix 6 Pro

Garmin Fenix 6 Pro Comparison Table

Advanced Running Dynamics

If you choose the Garmin Fenix 6 Pro, you open up an array of advanced running stats that aren’t compatible with lower end Garmin watches. The bullet points below explain these stats in greater detail. 

  • Ground Contact Time – The amount of time your foot spends on the ground with each stride.
  • Ground Contact Balance – The symmetry between your left and right foot when running. 
  • Vertical Oscillation –  The degree of upward ‘bounce’ in your running motion. Lowering this stat can increase running efficiency. 
  • Vertical Ratio  – The cost-benefit ratio with stride length. This allows you to discover the ideal stride length for chasing down a new PB. 
  • Cadence – Real time cadence stats displayed on the Fenix 6. 
  • Stride Length – Real time stride length stats displayed directly on the Fenix 6 Pro.  

There is just one thing you need to keep in mind. In order to unlock advanced running dynamics on the Fenix 6, you need to invest in one of the following 3 accessories. 

  1. Garmin Advanced Running Dynamics Pod
  2. Garmin HRM-Run
  3. Garmin HRM-Tri

Much Better Navigation Technology

The Polar Grit X does include a few navigation features. However, it simply can’t compete with the full spec TOPO maps that you gain access to with the Fenix 6 Pro. 

It’s a bit like having Garmin’s Car navigation technology packed into a wrist watch with a beautiful screen. The TOPO maps are particularly useful for urban running in unfamiliar settings, trail running, mountain biking and hiking. You literally gain access to a 3D map telling you where you are. In addition, the Fenix 6 also gives you: 

Turn by turn navigation: Follow a route or course with help from turn-by-turn directions, which let you know ahead of time when the next turn is coming.

Round trip routing: Enter a distance you want to travel, and get suggested routes that will bring you back to your starting point. Trendline™ popularity routing helps you find the best local paths.

Garmin ClimbPro: ClimbPro can be used to see real-time information on your current and upcoming climbs, including gradient, distance and elevation gain. It’s a very nice feature for trail runners and mountain bikers. 

Music Storage & Music App Compatibility

Simply put, the Garmin Fenix 6 Pro can store up to 2000 songs. That should be enough for even the most dedicated long distance runner. Then it’s also worth pointing out that the following music apps are compatible with the Fenix 6 Pro: 

  • Spotify
  • Deezer
  • Amazon Music
  • iHeart Radio

Advanced Golf Tracking

Polar list golf as one of the sports tracks by the Polar Grit X, but the simple reality is that these two watches aren’t comparable from a golf perspective. The Grit X will basically summarize your movement patterns, calories burned and miles walked during a round of golf. 

Conversely, the Fenix 6 Pro will give you all the same fitness stats, and very valuable golf data, including: 

  • Yardage to the whole
  • Yardage to hazards
  • Automatic measurement of shot distance
  • Digital scorecard
  • Round timer

In other words, the Fenix 6 Pro has almost all the same features that you would expect in a dedicated GPS golf watch. The same cannot be said for the Polar Grit X.

ANT+ Connectivity and WiFi Connectivity

ANT+ Connectivity: The main benefit here is that the Fenix 6 Pro is compatible with significantly more 3rd party cycling accessories than the Polar Grit X.

This is a longstanding weakness with Polar products, and something they will have to address at some point. For this reason, the Fenix 6 can be considered a better choice for cyclists that will more than likely encounter a cycling accessory that requires ANT+ connectivity to function optimally. 

WiFi Connectivity: This might not seem like such a big deal, but WiFi connectivity is amazingly convenient. Bluetooth can be slow at the best of times. WiFi doesn’t share this affliction. Once everything is connected, data transfer between your watch, your phone and your PC should become pretty seamless. Don’t underestimate how much time you can save and how much hassle you can avoid by using WiFi for data transfer. 

Super Long Battery Life & Power Management Features

The battery life settings of the Polar Grit X are impressive. 

  • Standard GPS Battery Life: Up to 40 Hours
  • Extended GPS Battery Life: Up to 100 Hours

However, the battery life options of the Fenix 6 Pro are insane. 

  • Standard GPS Battery Life: Up to 60 Hours
  • Extended GPS Battery Life: Up to 120 Hours
  • Expedition GPS Activity: Up to 46 days
  • Battery Saver Watch Mode: Up to 80 days

Furthermore, you can also customize the battery life settings to better suit your needs. Admittedly most people will be more than covered by the standard GPS battery life, but if you are into adventure racing, mountaineering or ultra long trail running, the power management features of the Fenix 6 Pro could come in handy. 

PacePro Race Guidance

Garmin PacePro provides grade-adjusted pace guidance throughout your activity, based on elevation and your personal pacing preferences. Viewing the pace profile on your compatible device shows your target pace for the current split along with a measure of how you compare to the target. 

Ultimately, if you want to hit a target race time, Garmin PacePro could be gamechanger. It helps you keep track with your target time, while factoring the likelihood of running slower during uphill sections of the route. 

Pre-loaded Ski Maps

If you’re into snow sports, it makes sense to go for the Fenix 6 Pro over the Polar Grit X. The Fenix 6 Pro boasts support for skiining, snowboarding and cross country skiing, and also includes 2000 pre-loaded ski resort maps. 

Moreover, you can add additional snow sport tracking features to the Fenix 6 by downloading custom apps through Garmin connect. Admittedly the Polar Grit X also has skiing and snowboarding modes, but it lacks the resort maps and the advanced stats that you can get through certain Garmin connect apps. 

Final Buying Tips

We’ve covered the key differences and the key similarities between these two watches. If you’re still undecided, these final buying tips may help: 

Go for the Polar Grit X if: 

  • You want the more affordable option
  • Your primary interest is tracking endurance sports effectively
  • You aren’t phased by the lack of music storage
  • You want built-in running power 

Go for the Garmin Fenix 6 Pro if: 

  • You want powerful navigation technology
  • You like training with music
  • You play golf regularly
  • You want the better smartwatch overall
  • You want the ability to customize data fields and download additional apps through Garmin connect
  • You’re a cyclist and you are likely to buy 3rd party accessories that require ANT+ connectivity