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Suunto 3 Fitness review: A fine concept but underwhelming in execution

Our Rating :
Price when reviewed : £170

The Suunto 3 Fitness aims to be your personal trainer, but we’re not wholly convinced


  • Training guidance
  • Bluetooth sensor compatiblity
  • Comfortable


  • Confusing interface
  • Basic app
  • Doesn't interface with Strava

The Suunto 3 Fitness is not your average fitness tracker. Unlike most wrist-borne wearables, which stop at giving you kudos when you set a new record and nudging you when you need to be more active, Suunto’s tracker automatically creates a personalised workout plan for you every week, based on your current fitness level.

Miss a workout or run ahead of schedule and the watch will simply adjust your schedule for the week ahead accordingly. What’s more, the Suunto 3 Fitness gives you guidance during exercise, alerting you when you’re not working hard enough and when you’re pushing it too hard.

Consider that it also tracks your stress and overall resources and it’s impossible to see how it couldn’t help you become a fitter version of yourself. But how well does it work in practice?

Suunto 3 Fitness review: What you need to know

If you want a fitness tracker that tells you when and how to train, the Suunto 3 Fitness might be just the watch for you but it isn’t for serious fitness enthusiasts for one simple reason: it doesn’t have built-in GPS.

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This means you’ll need to bring your phone with you and use the watch’s connected GPS function if you want to accurately track pace, speed and location on walks, bike rides or runs. There’s also no altimeter for logging stairs climbed.

Elsewhere, the Suunto 3 Fitness does most of the things you’d expect of a good fitness tracker, including counting steps, estimating calories burned, monitoring heart rate and even reporting on the quality of your sleep each night. It’s waterproof to 30m, too, so there’s no reason to take it off before going for a swim or taking a shower.

Suunto 3 Fitness review: Price and competition

The Suunto 3 Fitness will set you back £169, which places it in direct competition with the Fitbit Versa (£199). Although the Versa looks more impressive on paper thanks to smart features that include the option to store music and download apps, we found its synchronization and notification handling flakey, making it difficult to recommend.

For a good multi-sport watch that has built-in GPS, the Garmin Vivoactive 3 (£220) remains our favourite wearable. If you’re more into running than other sports, the Garmin Forerunner 30 (£99) and Polar M430 (£169) are other options worth considering.

Suunto 3 Fitness review: Design

It’s by no means ugly, but the Suunto 3 Fitness is pretty generic in appearance. In fact, at a glance, you’d easily mistake it for the Garmin Vivoactive 3 thanks to its circular black polyamide casing and stainless steel bezel.

Where it differs drastically from the Garmin device, though, is that it has no touchscreen, so navigation is via five buttons arranged around the watch’s edges. Yes, FIVE buttons. As you’d expect, working out what each button does can take a bit of getting used to and even after a few weeks week with the watch I often found myself pressing the wrong one and questioning the very purpose of others.

At only 28mm across, the always-on 218 x 218 matrix display is also on the small side – the steel bezel and a broad black surround make up the rest of the 43mm front. However, despite not looking particularly bright or vibrant indoors, the display is easily readable in bright sunlight.

Flip the watch over and you’ll find an optical heart-rate sensor made by US-based biometric tech company Valencell, which records your heart rate at regular intervals throughout the day as well as during workouts. Although this sensor protrudes from the back of the watch’s body by a millimetre or two I didn’t find it especially uncomfortable.

At 14mm thick, the Suunto 3 Fitness isn’t the most svelte device we’ve ever seen, but it is extremely light. Indeed, at only 21g without a strap (36g with the strap), it’s one of the lightest fitness-orientated smartwatches we’ve tested.

Suunto claims the 3 Fitness’s 20mm band will accommodate an impressive range of wrist sizes from 120-210 mm. Should you have smaller or larger wrists than this, or simply want a more eye-catching design, swapping it requires no tools and only takes a few moments.

For charging, the Suunto 3 Fitness uses a four-pin clip attachment. You might expect this to be more reliable than the magnetic connections used by some wearables such as the Ticwatch E and S but I didn’t find this to be the case. Although it locks in place securely most of the time, on occasion it wouldn’t sit slightly skewiff in the socket, leading to a failed charge.

Suunto 3 Fitness review: Features

After inputting your vital information, most of which I did on the watch rather than in the Suunto smartphone app, fitness insights begin to appear right away.

The watch’s home screen is limited to telling you the time, date and your step count for the day. Press the bottom right button, though, and you can jump through a series of widgets containing info about your heart rate, stress levels, steps, calories burned, fitness level, sleep and overall activity for the week.

There’s plenty to sink your teeth into here, but it’s a chore trying to locate what you want when you need it. After several days with the Suunto 3 Fitness, I was still learning how to access different data screens for each widget, which can involve pressing any one of three different buttons.

Even the watch’s main feature – its adaptive training guidance – is tricky to find. Pressing the middle-right button reveals whether today is a workout day and how long and hard you need to exercise for but commencing the scheduled workout requires five further button presses and checking your schedule for the rest of the week is more complicated still.

Still, once you’ve figured it all out, the training guidance is pretty useful. On a workout day, your scheduled workout appears at the top of the list of different modes in the watch’s Exercise widget and will be labelled 0:25h Hard, 0:45h Easy, or similar. This might sound a bit vague, but the great thing about this is that the watch doesn’t specify what type of exercise you need to do.

Instead, it explains which heart-rate zone you need to exercise within (and how that should feel in terms of your breathing and sweating) and you can then pick from a range of different activities including running, cycling, pool swimming, walking, indoor training and more.

Of course, if you’re super fit already you’ll struggle to reach zone 3 (the recommended HR zone for a hard workout) with a walk, so you need to use some common sense when it comes to picking an appropriate activity. But for more casual fitness enthusiasts, it’s excellent that the device lets you choose whatever you enjoy doing.

Suunto 3 Fitness review: Performance

If you start an outdoor activity when your phone hasn’t connected the watch will prompt you to open the Suunto app so it can use the phone’s GPS to track your speed and position. However, if you prefer to leave your phone behind, you can ignore this message altogether and track an activity using only the watch’s accelerometer. The app then guides you through the session, showing you your target HR zone and alerts when you need to speed up or slow down. 

On paper, that sounds great, but there are problems. The biggest was that we found the watch’s heart rate sensor somewhat unreliable. On one bike ride across London, for example, it took around ten minutes before the watch registered a pulse higher than 80bpm, despite me repeatedly checking it was securely attached to my wrist. Then, with no obvious reason, it suddenly shot up to over 100bpm.

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Cycling can often wreak havoc with optical heart rate sensors but fortunately the Suunto 3 Fitness is compatible with Bluetooth sensors, so connecting a chest strap is the best idea if you do a lot of cycling.

The connected GPS feature generally worked well, though. It usually found a fix within a few seconds and adds a range of useful live data including distance and speed to workouts, where it’s only estimated if you leave your phone behind. So far, so good.

The GPS was accurate, too, but what did cause a few problems was that the watch occasionally lost connection from my phone midway through a workout. Typically, this issue resolved itself in due course but when I reviewed an affected activity in the Suunto app later, the speed data clearly wasn’t entirely accurate, showing maximum speeds of up to 360 km/h. Ultimately, if you want to objectively know when you’re running faster and further, you’re always better off with built-in GPS.

Outside the adaptive training tools, one of the watch’s most interesting features is its stress-tracker. Using heart-rate variability data, the watch tells you whether you’re stressed, recovering, active or inactive and how long you’ve been in that state. At the touch of a button, you can also see what percentage of your total “resources” you have left – how much energy you have left if you like. Armed with this information, you should be able to establish whether it’s a good time to exercise, or crash on the sofa instead.

It’s not clear whether this data factors into how the Suunto 3 Fitness plans your schedule, but I’m unconvinced at how useful it is, particularly the resources figure. To give an example, one day, when I woke to feel drained and unwell, the watch told me I had 88% of my resources remaining, while on other occasions, especially when consulted later in the day, it said I had fewer resources even when I felt full of energy. In short, it’s difficult to know what you can do with this information, especially if you don’t trust that it reflects how you’re feeling at the time.

Heart rate info is only a press of a button away on the 3 Fitness, but again this widget left me feeling somewhat frustrated rather than enlightened. Like the majority of fitness trackers, you can only take a reading once the heart symbol stops flashing, but where some watches display something close to your current pulse within a few seconds, the Suunto device would always take longer, often starting considerably higher than the eventual reading.

My main gripe, though, is that, unless I wore the watch at night, the minimum heart rate reading didn’t usually correspond with the live readings I’d seen throughout the day. It’s fair that your pulse should be below a given number for a set amount of time before the watch counts it, but sometimes the Suunto device displayed a minimum heart rate of close to 70bpm even when I’d observed it regularly dipping below 60bpm.

Suunto 3 Fitness review: Suunto App

The Suunto 3 Fitness syncs your workouts with the Suunto app, and there’s plenty of detail to pore over here, but it doesn’t do much else besides. In fact, it’s staggering how little it records once you’ve finished exercising. There are basic summaries of how active you’ve been and how well you’ve slept over recent weeks but the vast majority of this background data seems to disappear into the ether.

To give one example, none of the continuous heart-rate data logged by the smartwatch is synced to the app. So unless you have a photographic memory or make note of your resting heart rate every day, then there’s no way of tracking this information over time and seeing how your body has responded to your exercise regime. That’s a fairly basic function that’s been totally overlooked.

The same is true of sleep tracking. The app makes note of the total sleep you’ve had but discards all the detailed and more interesting insights the watch provides every morning, which include the overall quality of your sleep and the total amount of time spent in different sleep states. And none of the stress and “resources” data goes is stored, either.

Compared with Garmin Connect, which lets you track your overall stress levels over days, week and even months to give you an idea of how much strain your body is under, the fact that the Suunto 3 Fitness’ shows nothing at all is a major letdown.

Another significant disappointment regarding the Suunto app is that it doesn’t interface with third-party apps including Strava and Runkeeper. Unless all your friends also have Suunto devices, or you’re happy just sharing a workout summary to Facebook, your friends won’t be able to crawl your data or give you kudos for a big workout.

Suunto 3 Fitness review: Verdict

The Suunto 3 Fitness has the laudable goal of simplifying working out for beginners. It automatically tells you when and how hard to train, so you don’t have to plan your own schedule. But it only succeeds to an extent.

For starters, the watch’s array of buttons and interface are fiddly and difficult to get to grips with. The biggest problem, though, is that, despite its recording heaps of data, a lot of this information is a mere distraction because it never finds its way into the Suunto app.

It feels like this final problem – the Suunto 3 Fitness’ biggest flaw – could be fixed with a simple software update and it ought to be. Otherwise, it’s very difficult to recommend the 3 Fitness, despite the fact that the watch itself is replete with features.