Best GPS Watches for Ultrarunning & Trail Running in 2021

Ultrarunners have very specific requirements when it comes to choosing which GPS running watch to buy. Because of these requirements, and the fact that the 4 leading brands for this niche are Garmin, Suunto, Coros, and Polar, my list of the best GPS watches for ultrarunning is small. Whoever needed too much choice anyway? Listed below are the features that ultrarunning watches should ideally have, to make them worthy of being a long term investment:

1. a very long battery life to be able to track vast distances over many hours, sometimes even days. There’s nothing worse than having your watch die on you in the middle of an ultra race.
2. actionable features that help us know when to adjust our effort levels, like a heart rate monitor, for example. Being able to know exactly how much climbing/elevation gain you have accumulated, with an estimate of how much still remains is invaluable data to an ultra runner.
3. navigation features in case you get lost in the mountains and need to find your way back on course or back to safety. Also very important if you want to explore new trail routes, without having to carry a map.
4. an on-wrist heart rate monitor – which is infinitely more comfortable than wearing a chest strap monitor!
5. good durability to withstand hours in the mountains during varying weather conditions, from rainstorms to the extreme cold but also environmental changes like river crossings, for example.
6. a comfortable fit for usage over many hours, especially important if you have small wrists and don’t want to be carrying a heavy weight around with you for hours on end.
7. a barometer to help us know our current elevation and when a potential lightning storm may be on its way so that we can take cover if necessary.
8. a good software platform for analyzing activity data and tracking our training performance over time.
9. the ability to play music, ready for when you need that pain-cave pick-me-up!

1. Garmin Fenix 6 Series (6S, 6 & 6X – Pro & Sapphire Editions) [EDITOR’S CHOICE]

Before getting into the features of each individual variation of the Garmin Fenix 6 series (there are A LOT), I’d like to point out that the Garmin Fenix 6S Pro variant is the watch we rate as the best GPS watch for runners, due to its small size, impressive feature set, and good price point. The difference between the Fenix 6S and 6S Pro is that the Pro has additional features including Music, Maps, and WiFi.

Some may like to upgrade this setup further by opting to add the sapphire scratch-resistant lens to the 6S Pro Sapphire. The sapphire lens will undoubtedly increase the durability and lifespan of your Fenix watch because once a screen is overly scratched, it can be difficult to distinguish data that is displayed on the screen.

Garmin has made so many options available that it can be a bit daunting knowing which Fenix GPS watch to choose for running with, so I thought I’d quickly share my choice of setup which in my opinion makes this the best GPS watch for ultrarunning.

The Best GPS Watch For Trail Running – Garmin Fenix 6 series Key Features

First off, lets talk about battery life in the different Garmin Fenix 6 models

• BATTERY LIFE – There are differences in battery life between the different Fenix 6 models, which you should be aware of when choosing a watch from the Garmin Fenix 6 series. See below for each watch and its corresponding battery life in each of the available modes:
  • FENIX 6S – Smartwatch: Up to 9 days / GPS: Up to 25 hours / Max Battery GPS Mode: 50 hours / Expedition GPS Activity: 20 days / Battery Saver Watch Mode: 34 days
  • FENIX 6S PRO – Smartwatch: Up to 9 days / GPS: Up to 25 hours / GPS and Music: Up to 6 hours / Max Battery GPS Mode: 50 hours / Expedition GPS Activity: 20 days / Battery Saver Watch Mode: 34 days. – Because of its smaller case size (42mm), the Fenix 6S Pro is perfect for women or men with small-to-medium wrists who don’t plan on running for more than 25 hours in one go. A smaller/lighter GPS watch also means it will remain comfortable for much longer than a heavier alternative. See below to find the best price for the Garmin Fenix 6S Pro.
  • FENIX 6 PRO– Smartwatch: Up to 14 days / GPS: Up to 36 hours / GPS and Music: Up to 10 hours / Max Battery GPS Mode: 72 hours / Expedition GPS Activity: 28 days / Battery Saver Watch Mode: 48 days. – This is the mid-sized watch and arguably the most popular because of it. See below to find the best price for the Garmin Fenix 6 Pro.
  • FENIX 6X PRO – Smartwatch: Up to 21 days / GPS: Up to 60 hours / GPS and Music: Up to 15 hours / Max Battery GPS Mode: 120 hours / Expedition GPS Activity: 46 days / Battery Saver Watch Mode: 80 days.This is the watch for the most serious of athletes that want the best realtime training insights available. This is the larger watch but it has the best battery life. See below to find the best price for the Garmin Fenix 6X Pro.

Other key features of the Garmin Fenix 6 GPS Watch range

HR MONITOR – The on-wrist heart rate monitor is accurate and more comfortable than a chest strap. This even works underwater, so you can track your heart rate while swimming, now that’s impressive.

PULSE OX SENSOR – For altitude acclimation or sleep monitoring, a Pulse Ox2 sensor uses light beams at your wrist to gauge how well your body is absorbing oxygen. Super useful when running at altitude or when used as an extra indicator for current fitness levels. ALL Fenix GPS watches now include this as standard, awesome!

NAVIGATION – The navigation features are excellent and in my opinion, the best in class. High resolution, color TOPO maps featuring trend line popularity routing to help you find and follow the best paths. This, in my opinion, is a fantastic feature that blows the competition away in terms of navigation. I love how easy it is to set up a course/route and then send it to the watch, ready for following during your run. Then when the route is displayed back to you on the watch, the detail is so incredible. When navigating a course you can also see the route profile with elevation gained and elevation remaining. I love this for being able to quickly visualize how much climbing I have left to crank out.

I love to explore new routes/trails, so being able to see the trails lines on the watch map that you shouldn’t take, makes it so much easier to see the ones you should, hence reducing the chances of getting lost.

DURABILITY – Rugged design especially if you opt to upgrade to a sapphire watch face. It will cost you an extra $100 but your watch face will be more resistant to scratches than other materials.

ALTIMETER, BAROMETER AND ACTIONABLE FEATURES – For accurate altitude/elevation tracking and weather tracking. When following a programmed course, you can set a real-time ‘ghost’ competitor which shows a marker on the watch to motivate you to keep up with it, this can even be your fastest time running that route, very cool.

SOFTWARE – Garmin Connect is a fun platform to store your runs on. There’s a wealth of data stored there so you can stick to built-in training plans and compete against friends. It can be used to track daily steps, heart rate, and sleep data too, provided you wear the watch all day. I like to automatically send my runs to Strava though as I have used the platform for a long time and have many friends on there.

WATER RESISTANCE – 100m

MUSIC – You can store up to 2000 songs on the watch which means you won’t need your phone with you to play music.

Those features are just some of the reasons why I rate the Garmin Fenix 6 Pro to be the best GPS watch for trail running.

Recommended US stores for Garmin Fenix 6S Pro:

Amazon.com	$591.00 23 new from $591.00 4 used from $499.99	See Deal
Rei.com	$650.00	See Deal
Garmin.com	$649.99 out of stock	See Deal

Last Amazon price update was: 21st April 2021 1:00 am

Recommended UK stores for Garmin Fenix 6S Pro:

Amazon.co.uk	£539.99 13 new from £484.49	See Deal
Sportsshoes.com	£599.99	See Deal

Last Amazon price update was: 21st April 2021 1:00 am

Recommended US stores for Garmin Fenix 6 Pro:

Amazon.com	$548.66 30 new from $548.66 3 used from $549.99	See Deal
Rei.com	$650.00	See Deal
Garmin.com	$649.99 out of stock	See Deal

Last Amazon price update was: 21st April 2021 1:00 am

Recommended UK stores for Garmin Fenix 6 Pro:

Amazon.co.uk	£479.00 19 new from £479.00 1 used from £439.99	See Deal
Sportsshoes.com	£599.99	See Deal

Last Amazon price update was: 21st April 2021 1:00 am

Recommended US stores for Garmin Fenix 6X Pro:

Backcountry.com	$699.99	See Deal
Rei.com	$700.00	See Deal
Garmin.com	$699.99 out of stock	See Deal
Amazon.com		See Deal

Last Amazon price update was: 21st April 2021 1:00 am

Recommended UK stores for Garmin Fenix 6X Pro:

Amazon.co.uk

£518.00 18 new from £518.00 3 used from £409.00

See Deal

Last Amazon price update was: 21st April 2021 1:00 am

2. Coros Apex – [MOST AFFORDABLE]

Amazon.com

$299.99 4 new from $299.99

See Deal

Last Amazon price update was: 21st April 2021 1:00 am

Coros is a lesser-known brand that is making serious waves in the trail running and Ultrarunning scene with the Coros Apex GPS Watch in particular [FULL REVIEW HERE]. The list of Coros pro athletes is impressive to say the least, including runners such as: Dom Grossman, Sally McRae, Timothy Olson, Cody Reed, Hayden Hawks, Camille Herron, Tim Tollefson, Adam Campbell, Paula Findlay, Magda Boulet, Jordi Gamito and Hillary Allen.

The APEX is the only Coros watch to offer two different watch sizes, 42mm and 46mm. This is great news for those who want plenty of features but don’t want to wear a bulky watch due to small wrists.

BATTERY LIFE – FOR THE 42MM SIZE – 24 days of regular use / 25 hours with full GPS / 80 hours with ‘UltraMax’ GPS mode

BATTERY LIFE – FOR THE 46MM SIZE – 30 days of regular use / 35 hours with full GPS / 100 hours with ‘UltraMax’ GPS mode.

Yes, with the UltraMax mode, the battery will last up to 100 hours using GPS (for the 46mm size), while using normal mode will yield up to 35 hours. This is easily enough for most ultramarathons.

HR MONITOR – The Coros Apex has an on-wrist HR monitor.

PULSE OX SENSOR – Not on this model.

NAVIGATION – Routes can be uploaded and displayed on a grid as a bread crumb trail with real-time information on heading and elevation. It also gives you alerts to help you get back on course, should you go off track. The navigation features are less sophisticated and detailed than the Garmin Fenix, for example, but if all you need is a pointer telling you if you’re on or going off-course, then the navigation features should tell you what you need to know.

DURABILITY – The Coros APEX features a sapphire glass screen for everyday and extreme protection. I really like the simple clean look of the APEX because it means you can wear it to work without it standing out too much. It’s also great knowing that you have the power on your wrist to do those impromptu long runs when you need to though.

ALTIMETER, BAROMETER AND ACTIONABLE FEATURES – The APEX tracks course, speed, time, pace – all the usuals, as well as elevation gain / loss, weather (via the built-in barometer) cadence, calories and heart rate. From this data the watch also calculates estimated fitness levels including VO2Max and lactate threshold, and the efficiency of your aerobic and anaerobic training activity.

The APEX is able to accurately determine your overall effort, broken down into stamina level (0-100) and training effect (0-6). This means COROS Trainer can notify you it’s time to rest up or to pick up your training. Based on the effort level and training history, you can then see an advised recovery window before you begin your next activity. This is available for Interval, Aerobic, and Anaerobic Training modes.

SOFTWARE – Once you’ve finished your workout, the COROS App will give you a complete graphical analysis of your training including VO2 max, recovery advisor, threshold pace, last-7 days training load, personal fitness index and plenty more.

Additionally, you can connect to your favorite 3rd party applications such as STRAVA and TrainingPeaks and automatically upload your workouts.

WATER RESISTANCE – Waterproof down to 100m

MUSIC – The Coros Apex does not have a music function.

Having an extremely competitive price-point, the choice of two lightweight watch sizes, a very impressive battery life, on-wrist HR, and many other features makes the Coros APEX our top pick for trail and ultrarunning.

Recommended US stores for the Coros Apex

Amazon.com

$299.99 4 new from $299.99

See Deal

Last Amazon price update was: 21st April 2021 1:00 am

Recommended UK stores for the Coros Apex

Amazon.co.uk

£269.99 1 new from £269.99

See Deal

Last Amazon price update was: 21st April 2021 1:00 am

RELATED LINKS:

• Coros Apex Review: The Ultimate GPS Watch For Trail Runners?
• Coros GPS Watches Compared: Which one should you buy?

3. Garmin Enduro [SUPREME BATTERY LIFE]

The Garmin Enduro, released in 2021, is built for extreme endurance athletes – and in particular, it is well suited to ultrarunning on account of its exceptional battery life and robust range of features.

BATTERY LIFE – Up to 80 hours in GPS mode, and 300 hours in ‘max battery mode’. 80 hours in GPS mode is truly market-leading, if you want to be able to accurately track your location with GPS continuously for as long as possible. The Enduro also features a new Garmin ‘PowerGlass’ solar charging lens that extends battery life. If you are using it in smartwatch mode, it can last for 65 days with the assistance of solar charging (the exact life varies depending on use and the amount of solar). You can also easily change which sensors are active, while on-the-go, to help conserve battery as needed.

HR MONITOR – Wrist-based HR monitor – and related to this this, other features relevant to trail runners and ultrarunners include:

• Trail Run VO2 Max
• Recovery advisor (how long to recover between workouts/runs)
• Advanced sleep monitoring
• ‘Body battery’ energy monitoring

PULSE OX SENSOR – The Enduro has a Pulse Ox sensor, which is used for altitude acclimation or sleep monitoring – the Pulse Ox sensor uses light beams at your wrist to gauge how well your body is absorbing oxygen. This is used together with the heart rate and breathing rates to support some of the aforementioned features, among others.

NAVIGATION – Yes – and while the GPS is accurate and quick to pick up (as you would expect from a premium Garmin GPS watch for endurance athletes), the navigation features are the only area I have experienced to date with this watch, where I would have liked to see more. The Fenix 6 range is hard to beat – and it seems that perhaps the Enduro’s ‘breadcrumb’-style navigation features have been used rather than the Fenix’s map-based tracking in order to contribute towards the exceptional battery life that the Enduro offers.

DURABILITY – The Enduro has either a stainless steel or lightweight, scratch-resistant DLC-coated titanium bezel. I also really like the webbing strap that comes as standard with the Garmin Enduro. It seems like a minor thing, however having a comfortable webbing strap can make a big difference over the silicone/plastic straps that can start to get annoying with longer wear durations, especially if you want to wear your watch overnight to track your sleep. This strap also contributes to its light weight, at 71g for the steel version and 61g for the titanium edition.

ALTIMETER, BAROMETER AND ACTIONABLE FEATURES – I think you get the picture by now. This watch has a ton of high-end features, and some of the altitude/barometer driven features include:

• Climbpro – Use this ascent planner to see real-time information on your current and upcoming climbs, including gradient, distance and elevation gain
• Navigate your next trail with ABC sensors, including an altimeter for elevation data, barometer to monitor weather and 3-axis electronic compass
• A pre-loaded ‘backcountry ski’ profile, which can distinguish between skiing and climbing. It automatically shows metrics specific to either ascent or descent.

I also really like the concept of the ‘ultrarun’ rest timer, which you can use to track your time in and out of checkpoints and rest stops during ultramarathon races, very much like a triathete would track their transition time. So you can see how much of your race you spent sat down eating fruit, cheese and noodles!

SOFTWARE – As mentioned above, I highly rate the Garmin Connect platform, and the software on the Garmin Enduro watch itself is easy to use and navigate on the go.

WATER RESISTANCE – 100m

MUSIC – Not on this model.

If you’re an endurance athlete with a passion for the extreme and demand the best in terms of performance, health and training features all in a comfortable and durable watch with market-leading battery life then the Garmin Enduro has your name on it! It’s truly an exceptional watch for ultrarunners.

Recommended US stores for the Garmin Enduro

Amazon.com	$899.99 6 new from $853.30	See Deal
Garmin.com	$799.99 out of stock	See Deal

Last Amazon price update was: 21st April 2021 1:00 am

Recommended UK stores for the Garmin Enduro

Sportsshoes.com

£699.99

See Deal

4. Suunto 9 Baro

Suunto 9 Baro Key Features

BATTERY LIFE – 25 hours of battery life with Performance mode, 40 with Endurance, and up to 120 hours with Ultra mode. The Suunto 9 Baro has great battery life and should be considered if you intend to run the middle of the pack ultra races of 100 miles or more.

HR MONITOR – The Suunto 9 Baro also has an on-wrist heartrate monitor.

PULSE OX SENSOR – Not on this model.

NAVIGATION – is available but not as feature-rich as the Garmin Fenix 6 Pro series. I find myself often taking the wrong turn when running new routes because of the lack of detailed maps on the watch.

DURABILITY – Rugged design with a sapphire watch face. Suunto really know how to make watches that last!

ALTIMETER, BAROMETER AND ACTIONABLE FEATURES – As the name suggests, this watch offers accurate altitude/elevation tracking and weather tracking.

SOFTWARE – Suunto’s Movescount is a pretty feature-rich although the options for visualizing data are not as comprehensive as Garmin Connect. I have noticed that transferring moves from the watch to the platform on a mobile device is slower than the Garmin equivalent. I notice more downtime with their servers too which means you cannot view your activity until the system comes online again (frustrating when you want to analyse that hard training run). Having said this, the platform is sufficient but I’d love to see more stability improvements.

WATER RESISTANCE – Down to 100m

MUSIC – No music available so you’ll have to rely on your mobile phone or music device (or the sound of nature). I prefer to save phone battery life for emergencies so will end up not listening to music during an ultramarathon unless my watch has the capability.

Recommended US stores for Suunto 9 Baro

Amazon.com	$499.00 5 new from $499.00 10 used from $281.12	See Deal
Backcountry.com	$499.00	See Deal
Rei.com	$499.00	See Deal

Last Amazon price update was: 21st April 2021 1:00 am

Recommended UK stores for Suunto 9 Baro

Amazon.co.uk

£472.56 2 new from £472.56

See Deal

Last Amazon price update was: 21st April 2021 1:00 am

5. Polar Grit X

The Polar Grit X is a watch that has almost all the features you could possibly want for trail running and ultrarunning, and for such a low price-point, you can see why it’s getting so much attention within the trail running community. If you’re not familiar with Polar, they’re a company who like to put a strong focus on heart rate training, which is important as your heart is the only real constant in knowing how fit you are at any given point in time. Our heart is our engine, and we are all unique, so it makes sense to train by heart rate as opposed to someone elses training plan, if you want to personally get better/stronger/faster.

This is a running watch that looks good enough to be worn for everyday life too (not just running), and I love how much attention Polar puts on heart rate training. They go one step further by actively tracking your sleep, provided you wear it to bed at night.

Polar Grit X Key Features (47mm)

BATTERY LIFE – The Polar Grit X has 40 hours of battery life in training mode (full GPS and wrist-based heart rate) or up to 7 days in watch mode with continuous heart rate tracking. I like that there are multiple power save options available too. 40 hours is the sweet spot for many mid range ultra races, and this is a great battery life for such a competitive price point.

HR MONITOR – On-wrist HR monitor, which I’ve noticed to be very accurate. It’s also used to track your heart rate as part of the sleep monitoring function.

Some other great features include FuelWise which aims to help you know when the best time is to refuel during a run, because the Polar Grit X is smart enough to know what fuel you’re burning the most; whether it’s carbs, protein or fats. The other feature I really like is ‘Hill Splitter’ which gives detailed data about your performance on the uphill and downhill sections of your session – for anyone who enjoys getting climbing steep hills or mountains, this watch will make those efforts even more enjoyable to sweat for. Learn more about all the smart Polar Grit X features here.

PULSE OX SENSOR – Not on this model.

NAVIGATION – The only downside to this Polar Grit X in my opinion is the limited Navigation software/features. It is available but not as feature-rich as the Garmin Fenix 6 Pro series. You don’t really get a map on screen when following a route, instead, similarly to the Coros APEX, you get a line to follow with turn notifications which leaves margin for error in choosing the wrong route when navigating trails that may be close together.

To create routes you’ll have to step outside of the Polar environment and use another service called KOMOOT. This unfortunately leads to a bit of a clunky experience when you want to create and follow new trails. If you’re not interested in running/exploring new routes in areas you’re unfamiliar with, then this won’t be an issue for you.

DURABILITY – The Polar Grit X has passed several MIL-STD-810G tests (military-level durability tests), including extreme temperatures, drop and humidity which makes it a very reliable tool to have with you when you’re in the mountains. It’s also a very lightweight watch, at 64g.

ALTIMETER, BAROMETER AND ACTIONABLE FEATURES – The Grit X tracks accurate incline, ascent, and altitude tracking during your runs.

SOFTWARE – The Polar Flow online software and smartphone app is really well constructed and easy to use. It’s a pleasure to use to track your training in a nice visual manner.

WATER RESISTANCE – Down to 100m

MUSIC – No music available

Recommended US stores for the Polar Grit X

Amazon.com	$409.00 10 new from $409.00	See Deal
Rei.com	$429.95	See Deal

Last Amazon price update was: 21st April 2021 1:00 am

Recommended UK stores for the Polar Grit X

Amazon.co.uk

£388.99 3 new from £388.99 1 used from £307.97

See Deal

Last Amazon price update was: 21st April 2021 1:00 am

Suunto vs. Garmin vs. Coros vs. Polar GPS watches for Ultrarunning Summary

In summary then, If you’re looking for an all-round performer that has feature-rich navigation, On-wrist HR + Pulse OX, a long battery life of up to 50 hours with GPS, and a very comprehensive online platform to store and analyze your activities then the Garmin 6S/6 Pro is my recommended choice.

If on the other hand, you don’t think you need all those features, and would prefer a less expensive, durable watch that has an impressive battery life and a simple interface, then the Suunto 9 Baro or the Coros Apex are both great choices. Also consider the Polar Grit X for its heart-rate focused features, price point good looks for everyday wear.

Finally, for the extreme endurance athletes seeking best-in-class ultra-specific training and recovery features, plus exceptional battery life, the Garmin Enduro is built with you in mind.

I really hope you enjoyed reading this Best GPS Watches for Ultrarunning and Trail Running Buyer’s Guide. If you did, please give it a share, and if you have any questions at all, please leave it in the comments below, I love talking about running gadgets! 🙂

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