Garmin Forerunner 935 review

A running and fitness watch with phenomenal battery life

Why you can trust TechRadar We spend hours testing every product or service we review, so you can be sure you’re buying the best. Find out more about how we test.

Garmin Connect

  • Garmin Connect lets you download watch faces and basic apps
  • Tracks sleep, steps, resting heart rate and stress
  • Allows you to get phone notifications on your wrist

The app which accompanies the Garmin Forerunner 935 is very strong, allowing you to monitor all manner of things and upgrade your watch with ‘apps’ and new watch faces.

The reason we’ve styled it as ‘apps’ is because these things are really rudimentary indeed, being things like the ‘WorkItOut’ exercise set mentioned previously, or alternative data screens to help you race better when running.

While these are good, you’re not going to get a huge amount from many of them without digging in hard to see what they can do, and it’s easy to give up and not bother after a short while.

It is cool being able to change the watch face though, and there are many nifty and customizable options out there.

What the Garmin Connect app does do well is… actually, nearly everything. You can track sleep, steps, resting heart rate and even stress with the Forerunner 935, and the latter is one that we got rather addicted to.

The great thing about the stress tracking is that it’s cumulative - yes, you can do things to help relax (and the 935 was recently imbued with a breathing meditative mode to help calm you, much like the Apple Watch 3… although not as good) but when it’s rising that will be because you’re around stressors.

Seeing it rise day after day tells you that something isn’t working out - are you sleeping well enough? (That can be tracked well within the app, so is easy to find out). Is work getting you down? Are your relationships healthy?

While it can be worrying in itself seeing your stress levels go up, being able to think why has been useful and forced us to rethink parts of our lives - when it starts to descend, you really feel like you’ve learned another thing about yourself.

There are a number of other cool features on offer here: connect your phone to the app and it’ll send notifications from your phone to the watch, and if you’re running or cycling with the phone in your pocket, it’ll use the data connection to ping your location to chosen loved ones using the LiveTrack feature.

Garmin could still do a lot more with this data, telling you what it meant in context and how to improve your life from it. That’s a criticism we’ve laid at the door of many manufacturers, but the fact Garmin seems to draw fairly accurate data makes it harder to take when it’s not used properly.

Battery life

  • Brilliant battery life
  • UltraTrac mode can extend it further but at the expense of accuracy

The battery on the Garmin Forerunner 935 is just out of this world. We managed to get 12 days’ use out of it, running nearly every day and having the watch connected to a smartphone and giving smart notifications on the wrist (such as messages, calls and WhatsApp missives) without missing a beat.

We asked a friend of TechRadar, who was about to do a huge duathlon, to test the Forerunner 935 to see if the stats bore out and they very much did:

“I started the watch on 90%, and it eventually died after 16 hours and 14 minutes. This was using the normal GPS mode with the heart rate monitor attached. However, I didn’t realize I’d left the Bluetooth mode on, which meant that during the cycling section I had my phone on to use the LiveTrack mode in my Garmin Edge 1000 cycling computer.

“This was also paired with the watch and drained some of the battery, and that’s probably the extra 46 minutes right there I would have needed to make the finish.

“Further savings would have been made if I wasn’t using the HRM, but this is a metric I’d rather have, especially in this type of event.”

The battery life was never something we worried about with the Forerunner 935, with a 17-20 mile run often only dropping between 10-20% of the battery, which is incredible given only recently these devices were three times the size and lasted a fraction as long.

We also tried the UltraTrac mode, an ultramarathon option where the Garmin Forerunner 935 will only ping the GPS every few seconds, thus saving huge amounts of power.

It’s terrible on accurate distance - we ran a half marathon with it, and it showed a race length of 14.1 miles - but at the same time it only dropped 3% battery from full, which was amazing.

Apart from some crazy models from China, the Garmin Forerunner 935 has the best battery life we’ve seen on a running watch.

Gareth Beavis
Formerly Global Editor in Chief

Gareth has been part of the consumer technology world in a career spanning three decades. He started life as a staff writer on the fledgling TechRadar, and has grown with the site (primarily as phones, tablets and wearables editor) until becoming Global Editor in Chief in 2018. Gareth has written over 4,000 articles for TechRadar, has contributed expert insight to a number of other publications, chaired panels on zeitgeist technologies, presented at the Gadget Show Live as well as representing the brand on TV and radio for multiple channels including Sky, BBC, ITV and Al-Jazeera. Passionate about fitness, he can bore anyone rigid about stress management, sleep tracking, heart rate variance as well as bemoaning something about the latest iPhone, Galaxy or OLED TV.