Polar Grit X vs Garmin Forerunner 945

Polar Grit X vs Garmin Forerunner 945

The Polar Grit X is basically a Polar Vantage V with military grade durability and a more rugged design. This is a good thing. The Polar Vantage V is an excellent multisport watch, and there is definitely a market for durable GPS sports watches like the Grit X.

The Garmin Forerunner 945 is a thoroughbred triathlon watch designed primarily for endurance athletes. However, it’s impressive array of features don’t stop there. It’s also packed with sports modes, music storage and world-class navigation technology. You could call it a lighter and more affordable Garmin Fenix 6 Pro. 

That’s a high level overview of what these watches are about. Now let’s dive into the details. 

Please note – We also have an in-depth Polar Grit X Review available here. 

Table of Contents

What are the main differences between the Polar Grit X and the Garmin Forerunner 945?

  1. The Polar Grit X supports running power from the wrist. This is arguably it’s number one selling point. The FR945 requires an accessory to unlock running power. 
  2. The Garmin Forerunner 945 supports music storage and apps. You can store up to 1000GB of music on the watch. 
  3. The Polar Grit X has military grade durability. This means it’s a bit tougher than the FR945 physically.
  4. The FR945 includes support for advanced running dynamics. This gives you 6 valuable running specific metrics.  
  5. The Forerunner 945 offers ANT+ support – This makes it a better option for cyclists, because so many cycling accessories require ANT+ compatibility to sync with GPS watches. 
  6. 3D Topographical Maps – This is a bit like having Garmin’s car GPS technology baked into the watch. It’s great for running, cycling and hiking in virtually any terrain. 
  7. The Polar Grit X supports more sports modes – 130 to be precise. The Forerunner 945 is limited to 30 sports and activity modes. 
  8. The FR945 is like a dedicated golf watch – You get pretty much all the same features that you can expect from a full-blown Garmin golf watch. 
  9. Touchscreen – The Polar Grit X has a touchscreen + button interface. The Forerunner 945 relies exclusively on buttons to operate the watch. 

Key Similarities Table - Polar Grit X vs Garmin Forerunner 945




Wrist-based HRM

Activity Tracking

Advanced Sleep Tracking

Indoor + Outdoor Running

Indoor + Outdoor Cycling

Indoor + Outdoor Swimming

Indoor + Outdoor Rowing

More than 20 Sports Modes

Triathlon Mode


Accelerometer + Compass

Barometric Altimeter

Route Guidance & Back To Start

Komoot Route Planning

Changeable Watch Straps

Native Running Power


With Accessory

3rd Party Running Power

Stryd + RunScribe

Stryd + RunScribe

Screen Resolution

240 x 240 pixels

240 x 240 pixels

Screen Size

1.2" (30.4 mm) diameter

1.2" (30.4 mm) diameter

Garmin Forerunner 945

Key Differences Table - Polar Grit X vs Forerunner 945




Less Expensive

More Expensive


64 grams

50 grams


47 x 47 x 13 mm

47 x 47 x 13.7 mm

Sports Modes

130+ Sports/Activities

30 Sports/Activities

Wrist-HRM Accuracy



Smartwatch Capabilities



Built-in Running Power

Military Standard Durability


Fuel (Food) Recommendations

Stress Monitoring

Pulse Oximeter

Music Storage & Apps

Payments from Watch


Advanced Golf Tracking with Preloaded Course Maps

WiFi Connectivity

ANT+ Connectivity

Advanced Running Dynamics

Temperature + Altitude Acclimation

Smartwatch Battery

Up to 7 Days

Up to 14 Days

Standard GPS Battery

40 Hours

36 Hours

Extended GPS Battery

100 Hours

60 Hours

Water Resistance



Garmin Forerunner 945

Comparison of Sports Modes

Polar Grit X Sports Modes Garmin Forerunner 945 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

Military Grade Construction

By introducing military grade construction to the Grit X, Polar are essentially taking their cues from the Garmin Instinct. Given how well the Instinct has performed for Garmin, it’s easy to understand why. 

The primary benefit is that the Polar Grit X is literally the most durable GPS watch that Polar has ever made. It smashes the Vantage V and the Vantage M in this respect. While there is nothing wrong with the build quality of the Forerunner 945, it can’t compete with the Grit X in terms of overall durability. 

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. 

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

On this point, it’s worth mentioning that both watches are fully compatible with Stryd and RunScribe+. 

Advanced Sleep Tracking

Polar’s sleep tracking technology is a notch above Garmin’s. With the FR945 you get total sleep, periods of moment and periods of restful sleep. By opting for the Grit X, you gain access to Polar’s Sleep Plus Stages Technology. 

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. 

130+ Sports Modes

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

Because the Grit X has open water swimming and triathlon capabilities, it rivals the Polar Vantage M and the Polar Vantage V in terms of the total number of sports offered.

The Garmin Forerunner 945 also has an impressive number of supported sports (30 in total), but the Grit X trumps this particular battle with 130 in total. Yip, that’s 100 extra sports to choose from. 

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. 

Main Reasons To Choose the Garmin Forerunner 945

Main Reasons To Choose FR945

Advanced Running Dynamics

By opting for the Garmin Forerunner 945, you can open up an array of advanced running stats that don’t come standard 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 FR945. 
  • Stride Length – Real time stride length stats displayed directly on the Forerunner 945.  

There is just one thing you need to keep in mind. In order to unlock advanced running dynamics on the Forerunner 945, 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

Music Storage & Apps

This is a solid win for the Forerunner 945. Where Garmin has invested solidly into music functionality, Polar have taken the opposite approach, stripping out almost all functions that aren’t directly related to sports and fitness.

To refresh some of the more important details, with the FR945 you essentially get: 

  • 1000 GB of music storage
  • Spotify compatibility
  • Deezer compatibility
  • Amazon music compatibility
  • iHeartRadio compatibility

Long story short, if you enjoy training with music, the Forerunner 945 is a better choice than the Polar Grit X. 

TOPO Map Technology

Typically, Garmin’s TOPO maps are only included with their most expensive watches, meaning the Fenix range and beyond. However, the FR945 was the first Forerunner to receive this premium feature, making the value offering of the watch very solid overall. 

TOPO maps great for trail running and hiking, and they are also very useful if you’re navigating unfamiliar streets in the city.

In a way, it’s a bit like having Garmin’s car navigation technology packed into a GPS watch. It’s safe to say that whenever you find yourself in unfamiliar terrain, TOPO maps will be very handy. You gain access to a full color 3D Map of the terrain, with 

ANT+ Connectivity and WiFi Connectivity

ANT+ Connectivity: The main benefit here is that the Garmin Forerunner 945 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 FR945 can be considered a better choice for cyclists, who are likely to want or own cycling accessories that only work with the Forerunner 945.

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. 

Proper Golf Mode

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 in this regard. The Grit X will basically summarize your movement patterns, calories burned and miles walked during a round of golf. 

Conversely, the Forerunner 945 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 Forerunner 945 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.

Additional Apps & Features Through Garmin Connect

With Garmin Connect IQ, you gain the ability to customize the Garmin Forerunner 945 to suit your individual quirks and preferences. This means you can download custom watch faces, add new training fields to the workout display settings, and ultimately extend the baseline functionality of the watch. 

More importantly, you also gain access to hundreds of different apps that are available through Garmin Connect IQ. Some popular apps include: 

  • Beep Test – See how you score on this classic endurance fitness test. 

  • 7 Minute Workout – 7 Minute HIIT workouts designed to push your body to the limit. Great for fitness freaks. 

  • Meditate – All the rage these days. The meditate app turns the Forerunner 945 into a dedicated mindfulness companion. 

  • Ski/Snowboard Tracker – Take your ski tracking to the next level with this app. It gives you detailed metrics, including distance, speed, ascent data and descent data. Bread and butter stats for snow sport people.

Obviously the options don’t end there. There are literally hundreds of additional apps to choose from on Garmin Connect

Garmin Forerunner 945

Final Buying Tips

If you’re still on the fence, these final buying tips may prove useful. 

Go for the Polar Grit X if: 

  • You want running power from the wrist
  • You want a super tough mulitsport GPS watch
  • You are likely to benefit from all the extra sports modes
  • Your main concern is tracking endurance sports efficiently

Go for the Garmin Forerunner 945 if:

  • You like training with music
  • You’re a cyclist and need ANT+ connectivity
  • You want access to advanced running dynamics
  • You play golf regularly
  • You want additional apps and features through Garmin Connect IQ
  • You want the better smartwatch overall

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