Adventure racers, ultra-runners and Ironman competitors all have one thing in common: the quest for a rugged GPS sport watch that'll match the endurance of their own crazy feats of durability.
It's tough to find a sports watch that has a battery life that can contend with the demands of a 100-mile ultra, while still letting you use all of its rich features.
Expert tips: Tech tips and tricks to run a smarter marathon
Yet while there are inevitable trade offs, some wearables are clearly more capable of going the distance. We've lined up the most fully-featured trackers with the best staying power...
Built for the outdoors, the Sunto Traverse is a rugged watch that's good for 100 metre water resistance, offers GPS and GLONASS (for added accuracy) plus there's built-in topographic maps to help navigate those tough trails.
Read this: The best outdoor GPS watches
There's also a host of useful cycling and running metrics on board and it even has a flashlight mode. It's the battery life that really impresses here though. You can expect up to 100 hours in navigation mode and 14 days when used in standard watch mode.
GPS battery life: 100 hours
Garmin Fenix 3
With GPS and GLONASS support for fast fix and good tracking accuracy, as well as outdoor navigation features like 3-axis compass, altimeter and barometer, TracBack and Sight'n Go and waterproofing to 100m, Garmin's flagship adventure tracker is a seriously capable piece of kit.
Must read: Garmin Fenix 3 review
But all that'd be nothing without the staying power to back it up. Fortunately the Fenix 3 rocks a battery life of up to 50 hours in UltraTrac mode, 16 hours in GPS mode and up to 3 months in watch mode, although this all depends very much on getting the settings right to maximise the lifespan.
If you want something with a smarter look or a heart rate monitor on board, Garmin has also recently revealed a trio of new Fenix 3 models.
GPS battery life: 16 hours
Suunto Ambit3 Peak Sapphire
Until, we get our hands on the new Spartan range, this is Suunto's answer to the Fenix 3 and it's every bit as much the endurance and adventure racing beast. It boasts route navigation, compass, altitude and even heart rate in the water when paired with the compatible chest strap.
Read this: Best wearables for triathlon training
It also offers multiple sport tracking in a single session and links up with the Suunto Moves app to give you more detailed stats, a bundle of community features and complete on-the-move customisation of the watch on the fly. In GPS mode, with the settings optimised, you'll get 30 hours of tracking.
GPS battery life: 30 hours
Garmin Forerunner 920XT
One of the most fully-featured multi-sport watches you can get your hands on, the Forerunner 920XT takes many of the best bits from Garmin's other devices and crams them into one multi-talented swim-bike-run tracker. There's Live Tracking from the Edge series, swim functionality you find in the Garmin Swim and Fenix 2, Running Dynamics that first aired in the Forerunner 620, and finally activity and sleep tracking from the Vivo activity monitors.
Wareable verdict: Garmin Forerunner 920XT
The 920 works with ANT+ speed and cadence sensors for cycling, has a full suite of running skills like a form-improving cadence metronome and even lets you create courses to follow. Importantly the general battery will last for up to 24 hours while switching to UltraTrac mode gives you a healthy bump up to 40 hours of GPS tracking, albeit less accurate.
A new Forerunner watch, the 735XT offers in-depth run analytics, advanced swimming stats and is compatible with the company's Vector cycling sensors for added data. It also adds the company's Elevate optical heart rate sensor which makes it debut on the XT range, and of course, you can add a chest strap via ANT+ if you wish.
GPS battery life: 40 hours
Polar's top end multi-sport timepiece, the V800 is at its best as a running watch but also pairs with cycling accessories to deliver good on-the-bike stats and pleasingly, when paired with the right heart rate chest strap, also offers heart rate tracking in the water, a big bonus for endurance swimmers out there.
Wareable verdict: Polar V800 review
There's a multisport mode, which allows you to easily change sports and record complete sessions. For the adventurers and hikers, there's also a barometric altimeter, a magnetic compass, and the ability to get upwards of 50 hours of battery life in a low-power GPS mode.
GPS battery life: 50 hours
Magellan Switch Up
The Magellan Switch Up has a standard battery life that won't go much beyond a stingy eight hours, but this multi-sport tracker comes with a clever trick that makes it a solid option for endurance events - a hot swappable battery extender packs that add 16 hours at a shot.
It's by no means as fully featured as something like the Garmin Forerunner 920XT but it with nine fully customisable sport profiles and the ability to track multiple disciplines as one single event - including transition time - and pairing with ANT+ add-ons to deliver additional tracking data, it's definitely one to consider.
GPS battery life: 8 hours extendable
It's all in the heart
- Best heart rate monitors and HRM watchesWant to get fit, fast and strong? Just listen to your heart
- This is what it's like using a stick-on heart rate monitorHeart rate sensing band aids have landed, but don't ditch the chest strap just yet
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