Garmin Forerunner 935 Review

The top dog in Garmin’s Forerunner range doesn’t disappoint

Garmin Forerunner 935
(Image: © Nick Harris-Fry / Future)

Our Verdict

Garmin has recently reduced the price of the Forerunner 935 to £389.99 now that it’s 18 months old, but despite its relative age it’s a superior sports tracker to everything else in that price bracket.


  • Superb battery life – 24 hours of GPS and two weeks in watch mode, resulting in between seven and ten days of use during a busy training schedule
  • Anaerobic and aerobic training effect stats give practical insight into the effect of your activities
  • The GPS locks in fast so you don’t wait around at the start of runs
  • A clear heart rate tracking screen makes it easy to keep track of the effort zone you’re in during exercise
  • Customisable screens mean you can display the data you want during your activities


  • No heart rate tracking for swimming activities (unless you buy the more expensive Tri-bundle)
  • Getting to grips with all the data and how to use it can be tricky for inexperienced athletes
  • The Forerunner 935 doesn’t have space for music or the ability to make NFC contactless payments, which are becoming common on newer Garmins in and even below the 935’s price range.

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Should I consider buying something else?

If you’re a keen runner or triathlete who only cares about sports tracking, I’d say no. At £389.99 there isn’t another running watch out there that’s as good as this. However, if you want those same sports tracking features, plus a more premium design, and smartwatch features like music storage and NFC payments, then it might be worth upgrading to one of the best fitness smartwatches such as the Garmin Fenix 5 Plus (£599.99), which also has colour maps. However, the Forerunner 935 is a lot lighter than the Fenix 5 Plus and has a better battery life, and having used both, I’d still lean towards the 935 as the better pure sports tracker because of that.

You can also get smartwatch features on the Garmin Forerunner 645 Music, which is a bit pricier than the Forerunner 935 at £399.99 and not quite as good a sports tracker, though it is still very impressive, especially for runners. If being able to store and stream music from your device is a dealbreaker for you, that’s probably a better bet.

If you don’t want to spend that much but are still set on a triathlon watch there are a couple of good options to consider. The Coros Apex 46mm (£299.99) has a massive 35-hour battery life in GPS mode and tracks running, cycling and swimming well, though it doesn’t track other types of exercise and lacks several features that the 935 has, including customisable workouts. There is also the Garmin Forerunner 735XT (£299.99), another older Garmin triathlon watch that’s still the equal of most current models, and the Suunto Spartan Trainer Wrist HR (£249), which boasts excellent navigation features and a multisport mode.

Garmin Forerunner 935 In-Depth

Using The Forerunner 935 For Step Counting

With its long battery life and comfortable design, the Forerunner 935 makes an excellent everyday activity tracker, even if most people who will buy it will be primarily concerned with more advanced stats than their daily step count.

The daily step target adjusts automatically in line with your activity and you can see how many steps you’ve taken by pressing down from the home screen, along with a bar chart of your last week of step tracking. Hit your daily goal and you get a celebratory screen featuring balloons. Lovely.

Using The Forerunner 935 As A Heart Rate Monitor

The 935 contains an optical heart rate monitor and you can also pair it with a chest strap for more accurate ticker tracking. The Tri-bundle comes with two chest strap trackers, a waterproof one for swimming and one for everything else.

Optical tracking is never going to be as accurate as a chest strap but the 935’s built-in monitor is impressive nonetheless. It will track your heart rate throughout the day and displays the previous four hours on a graph that’s available one press down from the home screen. The graph is colour-coded by five heart rate zones, showing any periods you were in a higher zone.

It also gives your resting heart rate and will plot it over seven days, four weeks and 12 months in the app. If it’s getting lower, you're getting fitter.

During activity your heart rate is shown on a dedicated screen which is also broken down by colour-coded zones, making it easy to read quickly. After your workout you can see a graph of your heart rate throughout and the time spent in each zone.

I found the heart rate tracking to be reliably accurate compared with a chest strap and was particularly impressed with the lack of lag during HIIT workouts. If you’re aiming to raise your heart rate with an intense workout, it’s good to know the 935 can keep up with accurate readings.

RECOMMENDED: The Best Heart Rate Monitors

Using The Forerunner 935 To Track Activity

Press the top-right button on the 935 and it brings up the activity list. The list is very long and you can make it longer by scrolling to the bottom to the Add Activity option. It’s safe to say whatever your particular sport is, the 935 tracks it. And if it doesn’t, there’s always the Other option.

For anything that requires it – running, cycling, open-water swimming – the GPS gets involved, and for everything that doesn’t need GPS you get heart rate, calories and time as standard. You can play around with the screens to display the data you want in the order you want it.

After the workout you are always told how it has affected your aerobic and anaerobic fitness on a scale of one to five – more intense, heart rate-raising sessions will do more for the latter, while steady efforts boost the former. All activities contribute to your overall daily “Intensity Minutes”, which is all time spent active.

To help fight the war against sedentary lifestyles, the 935 will buzz at you if you’re inactive for too long and tell you to clear its “Move Bar”. Some trackers just issue a reminder, some smartwatches offer video demonstrations of stretches, but a small, measurable goal like Garmin’s Move Bar seems like a much more motivating method to us.

The 935 will also automatically track certain activities, including running, cycling and walking. In practice, you’ll almost certainly not use this for running and cycling – if you don’t want to track these properly and view your progress on the go, why would you buy such an expensive, specialist device?

Garmin Forerunner 935

(Image credit: Nick Harris-Fry / Future)

Using The Forerunner 935 For Running

As the top dog in Garmin’s vaunted Forerunner line-up, the 935 offers a huge amount of features to runners. To start a workout you select run (or trail run, treadmill run or indoor track) and wait for the GPS to lock, which was generally very fast when outside. The longest I waited felt like 30-40 seconds and it was usually within ten seconds.

Hit Start and your mid-run screens come up. These are endlessly customisable and you can do it directly on the watch, so you can play around with them while running if you want to.

As an example I went for one screen showing time, distance, current pace and average pace. The next screen down was lap information, and the third screen down was heart rate tracking. There are plenty of other screens you can add, such as an elevation graph, a map or music controls, so it’s worth taking the time to set it up properly. You can also get Strava Live Segments on the 935, if you’re chasing Course Records.

The GPS is highly accurate, although I did find on a couple of runs where I repeated the same lap that it would shorten the distance covered the faster I went – only by less than 0.1km over 3km though, so it’s hardly the end of the world.

At the end of the workout you can see all the details on the 935 itself: pace, cadence, time in heart rate zones and so on. Some of the best information is in the Training Effects section, which covers the aerobic and anaerobic effect. If you’re a runner who always tends to stick with slow and steady jogs it won’t do a lot for your anaerobic fitness – you’ll need to throw in some sprints to get credit from the 935 on that front.

Once your run is completed you’ll also be told if you set any PBs and how long you should take to recover. You’ll almost certainly ignore the latter information – it can recommend as much as three or four days of rest – but at least the 935 is looking out for you.

Other long-term stats noted by the 935 include your VO2 max score and what bracket it puts you in, and its estimates for how fast you can run a 5K, 10K, half marathon and marathon. From what I’ve seen, these tend to be very generous so don’t be surprised if your real PBs are less impressive. I set a new marathon PB a couple of weeks before getting the 935, one I was very pleased with, only for the tracker to tell me I was 12 minutes slower than I could have been based on its metrics.

You can also set up an Intervals workout on the watch and download training sessions and plans via the Garmin Connect app. For more details on your running style you can buy a footpod and pair it with the 935. It really is a very comprehensive running companion – the best on the market in my opinion, especially considering the massive battery life.

RECOMMENDED: The Best Running Watches

Using The Forerunner 935 For Cycling

All the great features for running also apply to cycling and you can pair a power meter with the 935 to track your pedal power. There are three cycling options: bike, bike indoor and mountain bike. The screen on the 935 is large and clear enough to work as a bike computer if you take it off and attach it to your handlebars, although obviously you don’t get the optical heart rate tracking then.

Using The Forerunner 935 For Swimming

You can choose either pool or open-water swim as standard on the 935, which boasts all the swim-specific metrics you’d expect such as stroke count and SWOLF. It uses an accelerometer to measure your distance for indoor swimming – you have to set the pool length and then it will pick up on when you push off the end.

The GPS is used to track distance when in the open water. It’s less accurate than it is with running and cycling because the signal is lost when the 935 goes underwater, so you can expect the final distance to be up to 10% off – and you might find that it’s recorded that you were swimming on land at some points.

For both indoor and outdoor swimming the optical heart rate tracking is disabled, because the tech isn’t up to the job of providing an accurate reading in the water. If you opt for the Tri-bundle you get a waterproof chest strap to use for heart rate tracking when swimming. As well as the individual running, cycling and swimming modes the 935 has a dedicated multi-sport option.

RECOMMENDED: The Best Swimming Watches

Using The Forerunner 935 For Calorie Counting

For individual activities the 935 will give you the amount of calories burned in the summary. These all add up to your daily active calories tally, which is recorded along with your resting calories burned. These are added up for your daily calories burned total.

It’s a comprehensive and intelligent way to break it up, because it means you not only see how many calories you’re burning specifically from your activities but also have the overall total if you’re using it to guide how much you eat.

Using The Forerunner 935 As A Sleep Tracker

The lengthy battery life on the 935 means you can wear it all day and night without worrying about running out of juice, and despite its chunky form it’s just about light and comfortable enough to wear while sleeping.

Your sleep is broken down into deep, light and awake periods, and the 935 also gives you a graph of your movement in the night. All the info is presented well in the Garmin Connect app, but there’s not a lot of actionable guidance on how to improve your sleep. The sleep tracking on the 935 is solid enough, but it’s clearly not the device’s focus.

RECOMMENDED: The Best Sleep Trackers

The Garmin Connect App

When you first open the Garmin Connect app you are overwhelmed with information. The Snapshots section is overloaded with ten screens that each cover a different area – sleep, steps, weight, running, swimming and so on, and on. And on.

It’s too much, but once you delete all the ones you don’t care about, you can compress it down into a useful dashboard. I got rid of all the snapshots bar the My Day tab – which gives a (mercifully short) breakdown on steps, sleep, active calories, intensity minutes, activities and floors climbed all on one screen – and the dedicated tabs for running, cycling and strength/cardio training.

The Garmin Connect app does a good job of presenting all the data tracked on each activity in a clear fashion – no mean feat given the amount of info the 935 is sending to it. It lists everything, shows a map of your route for GPS activities and provides graphs of things like heart rate, cadence and pace.

The app plays nice with all the other major fitness apps you might be using, so even if you don’t like its layout you can send all the info elsewhere to peruse. You can also view all your data through an internet browser by logging into Garmin Connect.

How Often Am I Going To Have To Charge It?

As you might have picked up by now, I’m a big fan of the 935’s massive battery life. The times given by Garmin are two weeks in watch mode and 24 hours of GPS (which is bulked up to 60 hours if you put it on UltraTrac mode, which trades some GPS accuracy for extra battery life).

I found this translated to between seven and ten days of use even if I was quite active. If you just focus on one GPS activity you can expect ten days of battery life, and even if you are cycling to work on top of running regularly you’ll get through a week without charging. Even when it does run dry, it only takes a couple of hours to fully charge the 935.

Where Can I Wear It Without People Laughing At Me?

The all-black design of the 935 means it passes muster as a device that can be worn everywhere without it looking like you’re about to shed your suit and sprint off for a run. It’s bulky, and it’s not as presentable as the Garmin Fenix 5, but you certainly won’t feel like you have to take it off due to fashion concerns.

Nick Harris-Fry
Senior writer

Nick Harris-Fry is a journalist who has been covering health and fitness since 2015. Nick is an avid runner, covering 70-110km a week, which gives him ample opportunity to test a wide range of running shoes and running gear. He is also the chief tester for fitness trackers and running watches, treadmills and exercise bikes, and workout headphones.