Best Fitness Trackers for 2021



Finding The Best Fitness Trackers for 2021 for you with our buyer’s guide and run-down of Fitbit, Garmin, Apple, Huawei and Samsung models

Whether you’re considering buying your first fitness tracker or planning to upgrade your current one, it’s worth doing your research before you take the plunge. Fitness trackers used to be glorified pedometers, but now these smart gadgets have the ability to record and estimate all kinds of metrics across almost every sport and daily activity. This means you should be able to find a tracker that suits your lifestyle, and helps you maintain your health and achieve your sporting goals.
Basic trackers now cost less than £50, but to get features that improve on what any smartphone offers it’s worth spending closer to £100 for a good entry-level option. If you can stretch your budget a little further you’ll find trackers with all sorts of premium features like heart rate tracking, built-in GPS and touchscreens for between £100 and £250. Go above that mark and you’ll find the best smartwatches and more in-depth sports trackers; keen runners and triathletes will probably need the latter to satisfy their urge for stats.
There is a wide variation in battery life on fitness trackers. Some companies like Misfit and Withings use watch-style batteries that last as long as eight months before they need replacing, but most opt for rechargeable batteries. How frequently they need to be recharged varies widely, however: smartwatches tend to have the shortest battery life and can need daily charging, while fitness trackers usually last four to five days, and the best sports watches offer around 20-35 hours of GPS battery life so might only need plugging in every two or three weeks depending on how much you train.
If you’re new to this fitness tracking malarkey, we’ve included a rundown of the major features fitness trackers offer – with the benefits as well as limitations – so you can work out which could be useful for you. Or if you’re an old hand and already have a budget in mind, jump to our top picks in three different categories:

Fitness Tracker Features Explained

Step counting

Before heart rate monitors became standard, keeping track of your steps was the reason you’d wear a device all day, rather than just strapping one on for a workout. An accelerometer in the device senses movement and software translates certain movements into steps. It’s an imperfect method to say the least, as anyone whose fitness tracker has buzzed to celebrate a step goal while you’re sitting on the bus will know.
That’s not to say counting steps is pointless. Movement – steps or otherwise – is good and more movement is better, and it’s the little encouragements and challenges to induce you to move more and move regularly that can be beneficial to your health.
Fitness Trackers

Heart rate monitoring

Apple Fitness Trackers
It was once a feature restricted to high-end trackers, but most wearables now offer optical heart rate tracking. Some will only record your heart rate constantly during activities and take periodic measurements throughout the day to preserve battery life, but we think you should expect 24/7 monitoring on anything that costs over £100.
Optical tracking is usually pretty accurate during day-to-day life, but is more hit and miss during exercise, especially intense workouts. That can be especially problematic when certain tracker brands offer training sessions to follow that rely on you working on certain heart rate zones. Getting a tight fit with your tracker can help, but don’t expect miracles – if you want more accurate heart rate tracking it’s wise to link your device to a chest strap via Bluetooth or ANT+ if possible.
With heart rate tracking comes a wealth of other information, including an estimate of your VO2 max and resting heart rate, both of which are good measures of your overall cardiovascular fitness. High-end sports trackers also use heart rate tracking to provide info on the effect of your training session and how long you should spend recovering afterwards.

ECG Measurements

There are several fitness trackers available now that can take a medical-grade electrocardiogram (ECG) measurement from your wrist, which you usually do by holding your finger against one part of the device for 30 seconds. These ECG scans can detect atrial fibrillation, ie an irregular heartbeat – a common condition, but one that you will want to get checked out by your GP if a device does detect it.
Watches with the ability to take an ECG reading also often be able to monitor your heartbeat proactively to detect abnormally low or high heart rates, or prompt you to take an ECG if they spot any signs of an irregular heartbeat.
ECG-enabled fitness trackers require a CE mark in the UK and Europe, which means some devices that can technically do it don’t offer the feature yet while this certification is pending. Those that already have a CE mark include the Apple Watch, the forthcoming Fitbit Sense, Fitbit’s Ionic and Versa smartwatches via a third-party app FibriCheck, and the Withings ScanWatch. The Samsung Galaxy Watch 3 and Galaxy Watch Active 2 devices are awaiting formal certification.

Stress Tracking

Fitness trackers that have the ability to measure your heart rate variability – the time between your heartbeats – can use that info to rate how physically stressed you are. The higher the variability in this time the better, because it means your body is in relax mode, whereas low variability means your body is in action whether that’s because you’re digesting food, processing alcohol or just heading into an important meeting.
This state of physical stress is completely normal, but it does need to be balanced with downtime, which is usually when you’re asleep. Devices with stress tracking use your heart rate variability to give you a stress score, usually a simple number out of 100, which can be helpful in identifying whether you’re giving your body the chance to relax and recover regularly.

Sleep tracking

Sleep is just as important as exercise and diet when it comes to your overall health. Many trackers now record how long you spend asleep and break that down into periods of deep, light and REM sleep, allowing you to gauge your sleep quality.
This information can be useful if you pay attention to what might be responsible for a bad night’s sleep (eg booze) or a good one (eg no booze), but there is a limit to how useful this information can be. It’s not like steps where you can actively try harder to get more. However, the better devices can help nudge you towards better habits, allowing you to set reminders for a consistent sleep schedule.

GPS tracking

The addition of a GPS chip in the device means your tracker will accurately record speed, distance and elevation during outdoor activities like running and cycling. Cheaper trackers will use an accelerometer to estimate distance covered, with mixed results – see the perennial “fitness tracker doesn’t accurately track a marathon” story that comes out before the London Marathon every year. That exposé uses an accelerometer, while virtually every runner in the London Marathon will be using a GPS tracker. Some trackers offer an in-between option that connects to your smartphone and uses its GPS signal to offer more accurate tracking, which obviously means you need to have your phone on your person throughout your session.
A device with built-in GPS capability will be far more accurate in measuring distance than an accelerometer’s estimate, but it’s still not perfect. A manufacturer may decide to take readings less frequently to save the battery, which is why when you zoom into a map of your tracked route it can look as if you’ve passed through a building. Since a GPS signal is reliant on line of sight between your device and a satellite, it also means clouds and running in built-up urban areas can skew readings. If you’re committed to exceptionally accurate tracking, look out for trackers that offer compatibility with other satellite tracking systems – that’s GLONASS, the Russian equivalent of GPS, or Galileo, the EU’s satellite system.

Customisable workouts

Having an intervals mode on your fitness tracker is useful for guiding you through all types of workouts, if only because it will stop you extending your rest sections way beyond what they should be. On running and triathlon watches you’ll also often have the ability to set up more complex workouts, with work periods based on targets like distance, heart rate or pace, rather than just time. You’ll find a simple intervals mode on most mid-range fitness trackers, but for more complex customisable workouts you’re generally looking at spending over £250 on a sports watch.


If you’re keen on exercising outdoors then navigation is a great feature to look out for. It will not only stop you getting lost mid-run, hike or ride, but it’ll also help you to explore new places and avoid repeating the same routes near your house until you’re thoroughly bored with them. You can find basic breadcrumb navigation – where you get a line showing a preloaded course and pointer to show your position – on watches that cost from £200, while watches with full maps and on-the-go route mapping cost over £500.

Swim tracking

Almost all trackers offer some degree of water resistance, which means you can run in the rain or take a shower with them, but if you’re a keen swimmer you need not only a fully waterproof design, but also a dedicated swim tracking mode – some of the cheaper swimproof Fitbits merely offer automatic recording of time in the water.
We recommend settling for nothing less than the ability to track your laps in the pool automatically. More advanced watches will also offer stroke recognition and record stats like stroke rate and SWOLF, the latter a measure of your efficiency in the water.
Triathletes will also want an open-water swimming mode that uses a device’s GPS. This is something you’ll rarely find outside dedicated multisport watches that cost at least £250.


Having space for music on your tracker provides one more reason to leave your phone behind when exercising. Most smartwatches offer this feature now, and while all can stream stored tracks, some – like the Apple Watch – can handle their own data connection through either WiFi or, if you’re happy to pay a monthly data fee to a mobile network, a 4G sim.
We think the ability to sync with streaming services wirelessly is a key feature to look out for here. Being able to transfer over your favourite exercise playlist via wires is useful, but you can end up listening to the same music over and over again because let’s face it, plugging things in is a pain. If you can link to Spotify (which Garmin, Samsung and Android watches do), Apple Music (Apple Watch) or Deezer (Fitbit) and update that playlist wirelessly it’s much easier to put new tracks on your watch. However, you’ll need a premium account for those streaming services to use this feature, no matter which watch you use.

NFC payments (contactless)

With the ability to make payments from your watch, you can also leave your wallet behind when exercising outdoors. Smartwatches from tech companies like Apple and Samsung have got this down, having partnered with all the big banks when bringing payments to smartphones, but Santander is the only high street bank working with Garmin and Fitbit. More challenger banks are signed up, though, and there are third-party services available that are the digital equivalent of pre-paid debit cards.


Entry-Level Fitness Trackers (Less Than £100)

A modest budget is no barrier to picking up an excellent fitness tracker, as these four entry-level options show. Whichever feature you value most, be it heart rate monitoring, a long battery life or a waterproof design, you can find an effective tracker for under £100.
Best Apple Running Watch

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Fitbit Inspire Health & Fitness Tracker

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Fitbit’s new entry-level trackers, the Inspire and the Inspire HR, are both impressively full-featured devices that cost under £100, but we reckon the heart rate tracking of the Inspire HR is worth the extra £20. That’s because the heart rate monitor unlocks several first-rate features, including an estimation of your Cardio Fitness Score (equivalent to VO2 max) and resting heart rate, which are both helpful indicators of your overall cardiovascular fitness. The former is especially useful as it compares your score to other people of the same sex and age. Alongside heart rate tracking the Inspire HR logs all your everyday activity and sports, is waterproof so you can use it for swimming, and will link with your phone to offer Connect GPS tracking for outdoor activities.

Amazfit Bip Lite - Smartwatch Black

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The Bip is by no means a perfect device, but you can certainly forgive the accuracy issues it sometimes suffers from when you consider the following: it’s a GPS tracker with a one-month battery life, a big screen and a heart rate monitor, and it costs well under £100. It doesn’t look half bad on the wrist either. One important thing to note is that the Bip only tracks running, cycling and walking, so if you get your fitness kicks in some other way, you’ll find it limited.

Garmin Large vivosmart 4 Smart Activity Tracker

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One of the best things about Garmin is that once a new feature has appeared on its high-end trackers, it usually trickles down to the brand’s cheaper wearables. The Vivosmart 4 is laden with impressive features, including automatic rep counting, estimates of VO2 max and fitness age, all-day stress tracking and automatic activity tracking, as well as being waterproof so you can take it swimming.

It also has a built-in heart rate monitor for 24/7 tracking and a resting heart rate measurement, and it will even estimate your energy levels with the new Body Battery feature.


Mid-Range To High-End Fitness Trackers

As you’ve seen, there are useful trackers available for less than £100, but step above that mark and you open up a new world of exciting features like heart-rate monitors as standard, smartwatch-style notifications and even touchscreens. Get excited, people.
Best Polar Running Watch

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Fitbit Charge 4 Advanced

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The latest version of Fitbit’s wildly-popular Charge series fixes our biggest gripe with Fitbit – the persistent lack of built-in GPS. Even better, the Run Detect feature means you needn’t bother waiting for the device to lock on to a satellite, just set off on a run and the Charge 4 will fire up GPS run tracking automatically. Fitbit’s latest also debuts Active Zone Minutes, a feature built around the NHS-approved recommendation to get 150 minutes of activity a week, with more strenuous activities which get your heart rate up counting double. Add in swim tracking, Fitbit’s best-in-class sleep tracking, NFC payments using Fitbit Pay as standard and a stylish frame with a variety of attractive interchangeable bands, and you’ve got a great value package.

POLAR Ignite Fitness Watch

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The Ignite is a fully-fledged multisport GPS watch that can track pretty much any sport you can think of, but what really sets it apart is its unique ability to shape your training routine. The Ignite will rate how well you’ve recovered overnight and tailor a range of guided workouts for you to choose from, based on how ready your body is to train. It also has a bright touchscreen and a stylish design that you can wear everywhere to track your daily activity.

HUAWEI WATCH GT 2e Smartwatch,

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The GT 2e looks like a smartwatch with its large colour touchscreen, but since it isn’t compatible with the Google Play store and so can’t get apps a more apt description would be fitness watch, especially since it has built-in GPS and 100 workout modes to pick from. The watch’s battery life is also impressive thanks to the divorce from Google, with Huawei’s own software allowing the GT 2e to run for over a week between charges even when using it frequently to track exercise, and having the screen and heart rate monitoring on all the time.

There is also music on the watch, but only for Android users – the iOS app doesn’t allow you to sync songs to the GT 2e. Everyone gets access to Huawei’s excellent sleep tracking, however, and runners in particular are well served by the sports tracking: there are 13 preset workouts to use plus in-depth training and fitness analysis through a partnership with Firstbeat, which provides the same data analysis on Garmin’s sports watches.

The result is a pretty impressive all-round watch, especially given that it costs £160 and is often reduced on Amazon. For that you get solid sports tracking, great battery life and sleep tracking, and a smartwatch-level screen. Not bad at all.

Fitbit Versa 2 Health & Fitness Smartwatch

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The Versa 2 improves upon its popular predecessor by tweaking the design to make it more stylish, adding an always-on screen and introducing Amazon’s voice assistant Alexa, which we found matched up to Siri on the Apple Watch. The Versa 2 still doesn’t have built-in GPS (though you can connect to your phone’s GPS to track outdoor activities), which puts it at a disadvantage compared with several other watches in its price bracket, but it’s still a great smartwatch with music storage and streaming that offers excellent everyday activity tracking.

Apple Watch Series 3 (GPS, 38mm) - Space Grey Aluminum Case with Black Sport Band

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This Series 3 is a couple of years old now, but when its price was reduced to £199 recently, it immediately became a major player in the mid-range smartwatch market. The Series 3 doesn’t have the larger, always-on screen of the Series 5, but it is a terrific smartwatch that has Apple’s latest watchOS 6 software, built-in GPS, a heart rate monitor and, most importantly of all, access to the thousands of apps on the App Store.

Top of the Range Fitness Tracking Watches

Top of the Range Fitness Tracking Watches

A modest budget is no barrier to picking up an excellent fitness tracker, as these four entry-level options show. Whichever feature you value most, be it heart rate monitoring, a long battery life or a waterproof design, you can find an effective tracker for under £100.
Best Garmin Running Watch

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COROS APEX Premium Multisport Watch Trainer

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The Apex looks like a £500 multisport watch and has most of the key features of one too, yet it only costs £269.99 for the 42mm version and £299.99 for the 46mm. The battery life clocks in at a massive 35 hours of GPS on the larger version (25 hours on the 42mm) and the Apex offers detailed tracking of running, cycling and swimming, including a nifty Stamina stat for running that estimates how much energy your body has left. However, it does lack other sports modes, customised workouts are restricted to a simple intervals mode, and we have found the heart rate monitoring to be a little spotty while running. Still, given the price, this a stand-out option for triathletes and keen runners who don’t want to splash out big bucks on something like the Garmin Fenix 6 Pro.

Polar Unisex's Grit X - Rugged Outdoor Watch with GPS,

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The Grit X is a multisport watch with a feature set that will be particularly beneficial for adventurous off-road runners, with a 40-hour GPS battery life, turn-by-turn navigation and FuelWise, a feature that helps you to plan your nutrition for exercise sessions of over 90 minutes. It also has Polar’s detailed Nightly Recharge sleep tracking and will suggest cardio, strength and stretching workouts for you each day based on how well you’ve recovered overnight so you’re not overdoing it when your body hasn’t rested well. It’s well priced at £380, offering a little more than the watches you’ll find for £300 and below, and even including some of the features you’ll find on the all-conquering Garmin Fenix 6 Pro, which is much more expensive at £600. If you’re contemplating stepping up to ultradistance running but balk at the price of the Fenix, it’s well worth a look.

Apple Watch Series 5 (GPS, 40mm) - Space Gray Aluminum Case with Black Sport Band

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There is simply no better smartwatch out there. The Apple Watch Series 5 offers brilliant everyday tracking through the addictive activity rings system, solid native sports tracking plus the widest range of popular apps like Strava, music streaming and an easy-to-use wallet that can store cards and tickets. The latest version of the Apple Watch Series 5 didn’t add a whole lot in the way of new features compared with the Series 4, but the long-awaited arrival of an always-on screen is significant, especially for sporty types who can now see their workout stats at a glance without having to wake the display. The Watch also has the exceptionally accurate heart rate monitor that was introduced with the Series 4, which can take an ECG reading from your wrist.

Garmin fēnix 6 Pro, Ultimate Multisport GPS Watch,

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If money is no object, the Fenix 6 Pro is the best sports watch available today, offering runners and triathletes unparalleled detail on their training as well as smart features like music and colour maps that allow you to create routes on the fly. With the Fenix 6 range Garmin also introduced its smart PacePro feature, which can help runners pace their events perfectly based on mile or kilometre split targets that take into account the hills in that section, plus your overall time goal.