Garmin Forerunner 945 Initial Impressions

Thoughts on the Forerunner 945 after 2 weeks use, does it live up to all the hype?

Garmin Forerunner 945 Initial Impressions


For the last year I've been using the stellar Polar Vantage M watch exclusively and its done me proud; taking me from my first 10K all the way to 50K. The battery life was solid, it had good training features for interval sessions and it was accurate enough when tracing GPS and heart rate.

The one thing I always wished it had though was a maps feature. As a trail runner with an obsession with exploring new places, I'm usually following an unfamiliar route and go through the cycle of pulling my phone out, checking the navigation app to see where to go (usually with a bit of fumbling with my gloves, trying to unlock it) then locking the phone and putting it back. It sounds like a minor thing but it's time consuming, pulls you out of your rhythm and drains the phone battery.

I've had my eye on the Forerunner series for a while, specifically the 745, however seeing the battery life claims of the 945, combined with my needs in the Summer Green Man Ultra in August, I took the plunge with the top line model.

So, how does it hold up after 2 weeks usage?

Key Features

So far for me these are the killer features; you'll notice a big lean into the overwhelming amount of training data and advice it can give you:

  • Firstly the standard Smartwatch style features; it pairs with your phone, shows notifications and alerts, allows you to control music playing on your phone from the watch and the like
  • Next it's the accuracy of the device, both in terms of GPS position and heart rate accuracy, with plenty of reviews stating it's top tier level
  • Offline maps & navigation (discussed in the next section)
  • Music storage on device with Bluetooth headphone support (discussed later)
  • VO2 Max calculations based on your runs, which also give estimated race times for 5k, 10k, half and full marathons
  • PacerPro tool that uses course data such as elevation to tell you how fast to run to achieve a given time, adjusting the pace as you go to keep you on target
  • Workout builder on both the app and device itself, for building intervals, distance / time targets etc. It can generate workouts for you as well
  • Suggested workouts; when starting an activity tells you what it recommends you do that day
  • Training Status tracking; shows you your 7 day load, gives a recovery time estimate post activities, tells you whether you're doing the right type of training (too much high aerobic, not enough low for example), gives tips on how to improve your training
  • Body Battery metric; uses your heart rate variation and activity data to estimate your energy levels, giving you a good idea if todays the day to go for that PB or not
  • Intensity Minutes metric; allows you to set a target number of active minutes to aim for a week. Not ground breaking however where it differs is that high intensity exercise (like intervals) count more, so if you run hard you'll earn more minutes than the same time at an easy pace.
  • Finally, plenty of customisation; you can set custom watch faces, the data shown on them, which widgets appear on home and what screens to show during activities

Maps & Navigation

By far it's best feature, though one not exclusive to the 945 by any means, the map feature allows you to import a GPX route (or create one with the Garmin app) and display it on your watch with maps of the area as you run.

For my adventure runs this is the default screen I'll leave it on. I lock the keys so all I need to worry about is looking at the watch to understand where I'm heading next.

You are able to zoom and pan the map with the watch buttons, fiddly but functional considering once it's at the right zoom level you no longer really worry about it.

Twinned with this is it's navigation feature, which vibrates the watch, makes a short sound and lights up the screen as you approach a turning. This allows me to zone out when on a straight track, alerting me when that's about to change.

As an added bonus the map screen doesn't seem to drain battery any more than the other screens, so can safely be left on for longer runs.

There's also a "Back to Start" feature to help you navigate back to the beginning, useful for recce runs or general exploration. Not something I've used yet but keen to have a play.


Another tasty feature is its ability to store music on the device. You can either load your own MP3 files, or sync Spotify playlists to the watch.  From there you pair a set of Bluetooth headphones and off you go.

This is useful for when you want to go running without your phone, say local training runs round the block.

The music quality isn't as good as you'd get from a phone, but the connection was stable and good enough.

Note with music playing & GPS tracking the battery does drop down much faster.

How About That Battery Life

Outside of maps the most important feature for me is the battery life of the device. Garmin claims that it can last:

  • 14 days on normal watch mode
  • 36 hours GPS tracking in activities
  • 10 hours GPS tracking plus music playing in activities

These are pretty lofty claims and ones I'd certainly like to put to the test. With the Green Man Ultra coming up I'm going to need around 10-12 hours of GPS usage, maybe with a little music in there for a boost, in order to reach the finish line.

To test this I charged the device fully and refused to charge it again until it hit zero, here's what it covered:

  • Total of 6 days before needing a charge, consisting of the below activities along with general tinkering with the watch, messing with the stats and the like
  • Had the Bluetooth disabled for the most part, was not using it as a Smartwatch connected to the phone
  • 5 hour marathon using maps and navigation, no music
  • 40 min run with music playing over Bluetooth
  • 2 hour hike with maps and navigation, no music
  • 90 min run with maps, no music
  • 35 min run with no navigation or music
  • 30 mins playing music at home over Bluetooth

That gives us a total of ~10 hours active time, not bad, not brilliant.

Note I've seen the battery started out going down very quickly then slowed up towards the end of the week. Reading some forums it's claimed you'll start seeing better and better battery life after a few full charging cycles, so if you get this watch definitely drain and recharge the battery a few times first.

Also noticed that having the Bluetooth on drained the battery faster, so often only enabled it to sync data to the phone, the disabled it completely.

Based on this I'm confident it'll last me for the Green Man, but it may be quite close to the line 🙈. Reading around a bit it turns out however you can charge the watch from a power bank whilst on an activity, so the option is there if the battery does get a bit low.

Closing Thoughts

I'm 100% happy with the Maps & Navigation feature and that alone is worth the cost of entry for me.

However what has pleasantly surprised me is the amount of training data and proactive suggestions the device makes to aid with your training, it feels like your own coach strapped to your wrist.

The jury is still out on the battery life; it is more than sufficient for training, though a little close to the line for the ultra I bought it for. I'm hoping that a few charging cycles will improve it, will test with some back to back runs deeper into training. For now I'm still planning on having a backup tracker just in case.