The Garmin Forerunner 945 could last up to 10 hours in GPS mode. You could also use it as a smartwatch when you are not using it for running. And in smartwatch mode, it could last for 2 weeks.

It also comes with a feature called the UltraTrac mode – this allows you to do intermittent GPS tracking. And in this mode, it could last for up to 60 hours.

An excellent feature of this watch is its heartrate monitor. This is very important for every runner since it gives you the idea of when to slow down. If you go too hard without minding your heart rate, it could lead to unwanted situations.

The most popular feature of Garmin watches is its Navigation. It simply has the best navigation feature in the market. This feature reduces your chance of getting lost especially when its night time.

It's very easy to upload a route on your watch so all you need to do is follow it. Plus its high-resolution screen makes the details easily visible.

The watch also has a barometer which provides the elevation details. This is very important for runners since it gives them the idea to slow down a bit when the altitude is already too high or when you're approaching the peak.

When you choose this watch, you'll be assured of its quality. Garmin is simply the biggest name when it comes to the industry of running watches. You could enjoy using this watch for several years without failing. Aside from excellent quality, it also looks sleek enough to wear it anywhere you go. Many runners use it even if they are not running.

In choosing a GPS watch, the most important factor to consider is its battery life. Most smartwatch today could last for several days, however only a few could last long when the GPS is turned on. So make sure that you ask how long will the watch last when you use the GPS.

This is where the feature UltraTrac mode of Garmin Forerunner 935 is very useful. It periodically turns off the GPS to save battery life – best for ultramarathons. But for trail running events where you expect to reach the finish line in less than 10 hours, you could turn on GPS throughout the race.

The right watch to buy is one that has the important features you need aside from GPS. Some of these features are heart monitor and barometer. The details from these features allow a runner to adjust the level of effort on the race. It is important to slow down when the body is not feeling well. Elevation details provided by the barometer helps you know how much longer it would take for you to reach the peak of a mountain.

Durability is also an important factor to consider. This is why you need to invest in GPS watch with a good brand in order to be sure that it would withstand the varying weather conditions in running long miles on the trail. And after being ensured of its durability do not forget to check its fit. The watch also needs to be a comfortable fit in your hand.