What is the most accurate wearable fitness tracker?

Whether it's a slender Fitbit or a rugged smartwatch, the best fitness trackers can be invaluable to achieving your health and fitness goals. Studies have shown that using smart wearables can help you increase physical activity levels and improve body composition, according to a 2022 meta-analysis published in the journal Lancet Digital Health.

"Fitness trackers not only encourage exercise and weight loss, but may also help lower blood pressure and cholesterol in people with Type 2 diabetes and other health conditions," Nathan Kennedy, a certified personal trainer and representative for a sports nutrition brand Bio-Synergy, told Live Science.

The best fitness trackers don't just track your vital stats — they can map your running trails, tell the altitude, and even warn you when the weather conditions are about to change. Some may even act as a handy extension to your phone, thanks to smart features like contactless payment solutions, notification alerts or music playback. In fact, a good fitness tracker can be a convenient one-stop shop for all your needs. 

However, choosing the right fitness tracker is not an easy task. Smart wearables come in all shapes and sizes, and even the most tech-savvy shoppers may end up utterly confused at the sheer range of models available on the market. But that's where we step in. To help you find the best fitness tracker for you, the team at Live Science has spent countless hours testing some of the top ranking wearables. We looked at price, value for money, design, features, comfort, durability and battery life, as well as looks, ease of use, and connectivity with third-party devices. 

Read on to find out which fitness trackers ranked best, and don’t miss our guides to the best Fitbit and best Garmin watches, too.

The best fitness tracker overall

(Image credit: Andrew Williams)

If you're looking for great GPS and heart rate hardware, The Apple Watch Series 8 is a fantastic fitness tracker and our favorite of all the watches we've tested.

Apple really does offer best-in-class when it comes to health and safety features. In the Series 8, you’ll find an ECG monitor that can detect abnormal heart rhythms, a blood oxygen monitor and sleep tracking too. There’s also an advanced gyroscope for fall detection, as well as ovulation tracking for those with a menstrual cycle. These are all features that you can find in other trackers, but in our experience the heart-tracking capabilities of Apple outstrip its competitors. 

On top of that, the watch has an app library that’s bigger than all of its rivals put together. You can find second-party apps that will improve your yoga flows, help track your workouts and guide you on meditations. Compared with its predecessor, the Apple Watch Series 8 also offers more in-depth data on activities like running, including heart rate zones. You can even create custom workouts and save them to your watch.

But it’s not without its faults; the watch is only compatible with iPhones and battery life only lasts for one day. Still, we think the model is the best combination of value, features and performance available on the market.

• Read our full Apple Watch Series 8 review 

Best fitness tracker for advanced metrics

(Image credit: Andrew Williams)

A Garmin Fenix 7 is the best fitness tracker to get if you want the most comprehensive set of built-in exercise features available. These stand out when you bring other hardware into the mix.

The Fenix 7 series can connect to heart rate straps and foot pods, bike turbo trainers, and even Garmin’s bike lights. We liked that you can download continents’ worth of maps to the watch’s internal memory and plan hike, bike and run routes so you can leave your phone at home. 

It lets you download music and podcasts from some of the most popular music services, including Spotify and Deezer. And the MiP screen only becomes clearer in bright sunlight, so tracked outdoor sessions won’t kill the long-lasting battery. 

Its heart rate and GPS accuracy are great, and the presentation of stats like training load and VO2 Max seems tailored for the fitness enthusiast. 

A Garmin Fenix 7 may be a bit much if you just want to track 5km runs a couple of times a week. It’s not light and it’s not cheap. The bulk isn’t ideal for sleep tracking, so consider Garmin’s Versa 2 if you like the sound of Garmin’s style but would prefer something smaller. 

That said, Garmin’s watches are less intimidating than they once were. The Fenix 7 has a touchscreen and a quick swipe up from the watch face gives you a neat run-down of all your important daily stats. It has encyclopedic features, but works well for casual all-day tracking too. 

• Read our Garmin Fenix 7 Sapphire Solar review

Best budget fitness tracker

(Image credit: Sam Hopes)

The Xiaomi Smart Band 7 has joined the flock of one of the most popular wearable brands in the world, offering users features often reserved for premium-priced wearables. 

For $54.99, this fitness tracker is hard to beat for the number of features. Closely resembling the Fitbit in looks, the crisp 1.62'' AMOLED high-resolution display is glare resistant and 25% larger and brighter than its predecessor – the Xiaomi Smart Band 6. 

The Smart Band 7 is iOS and Android compatible, pairing with its own Mi app to give access to data like heart rate, oxygen monitoring, sleep, and workout analysis. You can also follow guided meditations via the app and check in on your daily stress level data. Xiaomi has thrown the kitchen sink at fitness enthusiasts, offering GPS tracking and 110 sport and fitness modes, including swimming (the watch is 50 meters waterproof) and yoga. 

We loved the female health management feature that allows you to track your periods and form patterns between your workout data and health stats. However, we found that a few features lacked accuracy, including sleep (and sleep stages) data and workout stats like calories and distance. The touchscreen also became unresponsive during sweaty workouts, which could be frustrating for activities like running or CrossFit. 

• Read our full Xiaomi Mi Smart Band 7 review

Best smartwatch for runners

(Image credit: Andrew Williams)

The Garmin Forerunner 965 takes the crown of the best fitness trackers for runners thanks to its user-friendly design, excellent navigation, and a wealth of useful features. 

The Forerunner watches have won our seal of approval multiple times, even despite the ever-increasing retail prices. We loved the Garmin Forerunner 955, but had to admit it was slightly too expensive for a watch with a plastic shell. The Forerunner 965 has stepped up its design, though — while the main part of the shell is still made from a plastic “resin”, its bezel is now crafted from rock-hard titanium. 

The Forerunner 965 screen boasts the biggest OLED Garmin has put into a watch to date, a 1.4in panel of 454 x 454 pixels. The display is also crisp, bright and colorful, making it easy to track your stats and follow the route on-the-go. 

The Garmin Forerunner 965 is packed to the brim with features that can help you level up your running performance. There is a good range of reliable health and activity stats to give you valuable insights into your cardiovascular health, exercise performance and recovery time. The Forerunner 965 is also equipped with excellent navigation systems and detailed maps, so you'll not veer off the track and get lost when running through unfamiliar places. Mind you, this model currently has the 8.8GB Europe Topo maps pack installed, but you can freely install others if you like. 

You also have 32GB on which to store any music you might want to carry around with you, smart notifications and handy workout suggestions to spruce up your exercise routine. 

• Read our full Garmin Forerunner 965 review

Best value fitness tracker

The transflective screen looks very clear, even in direct sunlight

(Image credit: Future/Andrew Williams)

5. Coros Pace 3

An excellent value-for-money fitness watch with impressive stat tracking accuracy

Our expert review:

☆

☆

☆

☆

☆

Specifications

Screen:

1.2-inch, 240x240 pixel screen

Water resistance:

5ATM

GPS:

Yes

Compatibility:

iOS, Android

Battery life:

Up to 24 days

Today's Best Deals

Reasons to buy

Reasons to avoid

The Coros Pace 3 is an ideal fitness tracker for those who might have been considering a Garmin but find them too expensive.

True, it is not made of Sapphire glass or stainless steel, but that is what keeps the weight and price low. Instead, the watch face is plastic with a 'mineral glass' top layer, and the strap is made of nylon. The whole tracker weighs just 30g; during our hands-on Coros Pace 3 review, we thought wearing it was an absolute pleasure. As it has 5ATM water resistance, you can easily clean its strap without having to remove the watch face.

One of the most impressive features for this price point is the dual-band GPS, which helps where the signal might be patchy, such as in busy built-up cities or dense woodland. You have to turn this on manually to preserve battery life when it's not needed.

Route syncing is another highlight. Draw routes on your phone and beam them over to your watch; it works surprisingly well at working out efficient running routes, but it only gives a breadcrumb line to follow rather than a map or turn-by-turn directions. Instead, it gives your wrist a buzz should you go off route, and an on-screen prompt tells you how off-course you are.

Countless watch faces are available in the Coros app to complement the five that come pre-installed. The display is 'always on,' so you don't have to tap it or 'wake it up' if you only want to glance at the time without getting distracted.

Overall, it is a great and stylish option for fitness watch buyers on a budget.

• Read our full Coros Pace 3 review

Best fitness tracker for stress management

(Image credit: Andrew Williams)

The Fitbit Sense 2 is one the most premium model from Fitbit, thanks to its combination of features and sleek AMOLED display. It’s relatively well-priced, too, regularly discounted from its original price of £299/£269. While you won’t get all the high-end features found on Garmin watches, you do have some other tasty extras, such as the EDA scanner. This measures ‘stress’ by basically reading how sweaty your hands are – if the model senses that you’re feeling hassled, it will suggest some meditation practices.

The watch also comes with an ECG scanner, which offers some insight into your heart health and will give you alerts if your heart rate is unusually high or low. We found it a little flaky during exercise, taking about five minutes to start working accurately. 

The Sense 2 has 40 workout modes, although we found some of them are more or less the same with a different label attached. 

The overall design is good; it’s not so clunky that it feels uncomfortable to wear during sleep. The large screen makes the display easy to read, even in sunlight, and we were impressed by the six-day battery life. Unfortunately, there is no music support, and the “always on” mode, while a handy upgrade from the original Sense, drains the battery life significantly. 

• Read our full Fitbit Sense 2 review

Best smartwatch for sleep tracking

(Image credit: Lloyd Coombes)

If you are looking for a fitness tracker that can help you get a more restful shut-eye, you can't go wrong with the Fitbit Charge 5. It’s rare to see a fitness tracker this small that is so comprehensive in the stats it can gather, and Fitbit’s sleep tracking is among the best on the market. 

But it is not just the extensive sleep metrics that make the Charge 5 stand out among competitors — it is one of the best Fitbit models out there, we dare say. If you have your heart set on a Fitbit, you just have to decide whether you’d prefer this or the bigger, more expensive Fitbit Sense. This model is much smaller, as it's more of a band than a watch. And you don’t get the downloadable apps available on Fitbit’s Versa and Sense — like Spotify, for example. If you want to go for a run and listen to music, you’ll have to use your phone if you’re using a Charge 5. 

However, the sheer amount of stuff Fitbit packs into the Charge 5 is impressive. It has full GPS, for phone-free route tracking. It has the EDA stress sensor Fitbit introduced in the Sense watch, and even an ECG sensor. This analyses your heart rhythm to check for abnormalities, using hardware completely separate from the optical heart rate reader on the back. 

Mind you, to see the Fitbit Charge 5 at its full strength you’ll need to sign up for Fitbit Premium. It costs $9.99/£7.99 a month and the watch includes a 6-month trial. While a Charge 5 works fine without it, fitness plans and even blood oxygenation readings sit behind this paywall. 

• Read our Fitbit Charge 5 review

Best screen-free fitness tracker

(Image credit: Future)

8. Whoop 4.0

Best screen-free fitness tracker

Our expert review:

Specifications

Screen:

N/A

Water resistance:

IP68/2M depth

GPS:

No

Compatibility:

iOS, Android

Battery life:

4-5 days

Today's Best Deals

Reasons to buy

Reasons to avoid

The Whoop 4.0 does not resemble any other fitness tracker on the market — but that's what makes it so special. This peculiar-looking wearable lacks a giant touchscreen or bulky buttons; instead, it comes with a discrete “sensor suite” and a woven, elasticated strap. It may come as a surprise, but the Woop 4.0 does not count steps, either. What you get, however, is continuous monitoring of health metrics including heart rate, skin temperature and heart rate variability, as well as in-depth sleep tracking. This data is then combined and analysed to produce three easy-to-understand daily scores; strain, sleep and recovery. 

We tested the Whoop 4.0 for nearly a month, and found this alternative approach had both benefits and drawbacks. This fitness tracker will not find any devoted fans among endurance athletes, since it does not have a screen, in-built GPS or other features that display stats while running. On the other hand, its discreet, screenless design will appeal to swimmers and weightlifters. The Whoop 4.0 feels sturdy, durable and shows no signs of damage after being smacked with a dumbbell or submerged in a swimming pool. 

The strain, sleep and recovery scores allowed us to get the most out of our training sessions without having to ponder on the individual metrics. But if you like your numbers, you can still get plenty of in-depth data on the Woop's dedicated app.

• Read our full Whoop 4.0 review

Best mid-range fitness tracker

(Image credit: Emma Hall)

9. Amazfit GTR 3

Best mid-range fitness tracker

Our expert review:

Specifications

Screen:

1.39in 454 x 454 OLED

Water resistance:

5ATM

GPS:

Yes

Compatibility:

iOS, Android

Battery life:

Up to 21 days

Today's Best Deals

Reasons to buy

Reasons to avoid

The Amazfit GTR 3 is a fitness tracker that looks a lot like a smartwatch. It has a super-sharp 1.39-inch OLED screen similar to the display of the Samsung Galaxy Watch 4, which is a lot more expensive. 

Its outer casing is aluminium, and it has a rotary crown controller similar to the Apple Watch Series 7’s. The back of the watch face, which sits on your wrist, is plastic. But this just sums up what the Amazfit GTR 3 is all about. Amazfit tries to pack in features and higher-end style where you’ll notice it, and leaves out more expensive parts where you won’t. 

The Amazfit GTR 3 comes with full GPS and an optical heart rate reader with six light-sensing photodiodes. It also packs more than 150 workout modes, menstrual tracking, Amazon Alexa support, and 5ATM water resistance. Cherry on top? Fantastic battery life of up to 21 days (6 days if you use the always-on screen mode). 

The message is clear: the Amazfit GTR 3 does a lot, for not all that much money. It’s important not to expect stellar depth or accuracy, though. The heart rate sensor is not as good at tracking interval workouts as an Apple Watch or Garmin Instinct 2, and unlike the “Pro” version of the GTR 3, you can’t load this watch up with music for phone-free workouts. 

• Read our Amazfit GTR 3 review

Best looking fitness tracker

(Image credit: Future)

We've tested both the Withings Scanwatch and the recently released Withings ScanWatch Horizon — and the original model remains our favorite. It expertly blends a fashionable wristwatch design with high-tech health and fitness tracker. 

We loved testing this sophisticated watch, playing with features like on-the-spot oxygen and ECG monitoring, sleep and fitness tracking, and basic metrics on calories and step count. It’s brilliant for gathering comprehensive data on your health, helping to provide a holistic picture of your wellbeing. 

The crown on the side of the watch flicks through features on a small digital screen within the clock face, bringing old and new together into one medical-grade wearable. 

The Withings ScanWatch is iOS and Android compatible and partners with the Health Mate app, where you have access to a dashboard of data like blood pressure, average heart rate, and more in-depth sleep analysis. You can also link up to third-party apps including Strava and Apple Health, and set up weight loss goals, macro tracking, or step count. It’s even waterproof (up to 50 meters) if you fancy taking it for a swim, but it’ll set you back a cool $279.95/£249.95.  

• Read our full Withings ScanWatch review

Best fitness tracker ring

(Image credit: Future)

11. Oura Ring (Generation 3)

Best fitness tracker ring

Our expert review:

Specifications

Screen:

N/A

Water resistance:

10ATM

GPS:

Connected only

Compatibility:

iOS, Android

Battery life:

4-7 days

Today's Best Deals

Reasons to buy

Reasons to avoid

We were impressed with the performance of the Oura ring during our month-long testing period. Its accurate sleep tracking is the real stand out feature; we found that whenever we woke up feeling groggy and poorly rested, the Oura ring was able to show us exactly when our rest had been disturbed and how it had affected our REM sleep.

The ring is able to take this data and make suggestions too. For example, our tester was advised to shift their workouts to earlier in the day and found that doing so had a positive impact on their sleep latency (how long it took them to fall asleep.)

As the ring is so small, it doesn’t have a screen. Instead, you’ll have to rely on a companion app to look at most of your health data. We didn’t find this to be a massive issue, although it does mean there’s no easy and quick way to check things like your heart rate when you’re in the middle of a workout.

There’s an impressive amount of data gathered by the ring. It measures your heart rate at various intervals throughout the day, along with your heart rate variability at night, to help check for potential health problems. And it has a helpful ‘readiness’ feature that will let you know if you should prioritise exercise or rest.

We did find that it’s not 100% accurate at tracking all health metrics. For example, we found it massively over estimated calorie burn during our testing period. And its ‘auto-detect’ feature often attributed the wrong exercise to our workout, for example recording a HIIT session as a weights session.

Despite this, we really rate it, thanks to its unusual design and brilliant, unmatched sleep-tracking ability. 

• Read our full Oura ring Generation 3 review

Best Apple Watch alternative

(Image credit: Andrew Williams)

If you want a Fitbit that’s similar to the Apple Watch, the Versa 4 has a ton of the same features. It can track heart rate, temperature, blood oxygen level (spO2), as well as the usual steps and calories, but it’s half the price of an Apple Watch Series 8. In fact you could put the money you save toward a Fitbit Premium membership ($9.99/£7.99pm), which opens up access to loads of extra content and features.

One thing Fitbit is really good at is sleep tracking, and the Versa is no exception. You can monitor your sleep patterns through the night and the spO2 sensor will measure your blood oxygen levels so you can track the data when you wake up (although bear in mind some of the stats can only be accessed if you have a Premium subscription).

As you’d expect, the fitness tracker syncs with your smartphone (iOS or Android) and  can receive notifications from any app on your phone. You can also talk to Amazon Alexa through a Versa 4, by long-pressing the side button. This works fairly well, but if your phone isn’t nearby, and connected over Bluetooth, Alexa won’t work. 

Fitness tracking performance is not top-tier, but probably fine for more casual use. Battery life is in step with this style too. We found it can last an estimated 6.2 days with around 45 minutes to 1 hour of GPS tracked exercise every other day. 

Our main gripe is that offline music has been removed since the Versa 3, with the watch no longer supporting any form of music.

• Read our full Fitbit Versa 4 review

Best for accurate fitness tracking

(Image credit: Tantse Walter)

13. Samsung Galaxy Watch 4

Best smartwatch for fitness tracking capabilities

Our expert review:

☆

☆

☆

☆

☆

Specifications

Screen:

Circular Super AMOLED 1.2 inch / 30.4 mm

Water resistance :

IP68

Compatibility:

Android

Battery life:

40 hours (depending on use)

GPS:

Yes

Heart rate monitor:

Yes

Reasons to buy

Reasons to avoid

Fitness trackers are never precise, but some wearables may be more accurate at tracking your health data than the others — and that's not necessarily down to their price. The Samsung Galaxy Watch 4 is not the most expensive or advanced smartwatch on the market, but when it comes to reliability of its data, it easily blows the competitors out of the water. 

We assessed its health and fitness tracking abilities by comparing the measurements obtained with the smartwatch to the values obtained with more professional devices. We were amazed how similar they were, and that's something we do not see often.

The Samsung Galaxy Watch 4 can also make calls, read and reply to messages, set calendar reminders, control your smart devices, and even pay for your shopping. It is highly customizable, too — the Galaxy Watch 4 works with a range of third-party apps and its straps can be easily changed so they better match your outfit. 

True, this isn't the newest model of Samsung Galaxy Watches, but it does not differ much from the newer Galaxy Watch 5. Compared to its younger sibling, it comes with slightly shorter battery life and a more delicate display, but otherwise it offers the very same features. And given that the cost of living is in full swing right now, we've decided to include on the more affordable Samsung Galaxy Watch 4 model.

• Read our full Samaung Galaxy Watch 4 review

Best value outdoor smartwatch

(Image credit: Andrew Williams)

14. Coros Apex 2

Good value for high-end hiking and adventuring features.

Our expert review:

Specifications

Screen:

1.2in 240 x 240 Memory LCD touchscreen

Water resistance:

5ATM water resistance

Compatibility:

iOS and Android

Battery life:

Up to 17 days

GPS:

Yes

Heart rate monitor:

Yes

Today's Best Deals

Reasons to buy

Reasons to avoid

The Coros Apex 2 strikes a perfect balance between quality and affordability. And although this rugged smartwatch was designed with outdoor enthusiasts in mind, it can pull some serious weight in the gym, too. The Apex 2 is relatively light and compact, looks good on the wrist, comes with a long-lasting battery life, and boasts an eye-pleasing design — we reckon it can easily compete with the top offerings from Garmin, Fitbit and Apple.

In addition, the Coros Apex 2 is one of the least expensive ways to get a dedicated fitness watch with true on-watch mapping that does not need any kind of internet connection to work. And yes, Garmin’s mapping features may be more advanced and detailed, but the price of entry is higher for those. And the Coros Apex 2 beats such models with its use of durable materials like titanium and sapphire. 

In our view, its health tracking abilities fall slightly behind those of the best from Garmin or Apple, but this mostly seems to affect all-day readings. But if you do not mind these tiny discrepancies, the Coros Apex 2 can be an invaluable companion on hiking trails. 

• Read our full Coros Apex 2 review.

How we test

How do we test fitness trackers at Live Science?

You can trust our recommendations when it comes to picking the best fitness trackers; each product on this list has been tried and tested by our expert fitness team. We gathered a range of top wearables and put them through their paces, wearing them for a variety of activities including running, swimming, gym sessions, HIIT workouts, and more.

We looked at the features, feedback and metrics on offer from each one, from the industry-standard step-counters to more detailed data like heart rate variability and blood oxygen saturation. Other factors considered included their design, comfort and performance, with our experiences in each area used to decide a final score out of five stars. 

FAQs

Garmin vs Fitbit: which is better?

Garmins are for fitness nerds, Fitbits are for those who would prefer a tracker with a more friendly face. That has been the traditional take on these two brands, and it still mostly holds up in 2024.

Garmin’s best fitness trackers offer significantly better core stat accuracy and reliability than Fitbit in our experience. A recent Venu/Fenix/Forerunner wearable will typically deliver superior heart rate readings to a Versa/Charge/Sense watch.

The latest Garmins also have more advanced GPS, with support for multi-band reception and Galileo. Don’t know what those are? It means you’ll get reliable signals across a wider range of locations and environment types — but that probably won’t have much of an effect if you plan on going for runs around your local park.

Garmins are clearly the obvious pick for the hardcore crowd. However, Fitbits tend to have a more deliberate sense of style, and their prices don’t reach anything like the heights of the top Garmin trackers.

The “high end” Fitbit Sense and Charge 5 cost about as much as some entry-level Garmin models. These two in particular also have a couple of features not seen in Garmin rivals.

They have ECG/EKG hardware, to monitor sinus rhythm, and an EDA sensor (which uses the ECG hardware) that estimates stress levels. Both of these require active participation — you hold a finger to the watch bezel — but are nifty health-related extras.

Apple’s Heart Study from 2019 found 34% of those who were given an alert from their Apple Watch’s ECG did indeed have atrial fibrillation. It can be a genuinely useful feature from a health perspective.

(Image credit: Andrew Williams)

Fitbit vs Apple Watch: which is better?

Fitbit makes a wider array of wearables than Apple. There’s the affordable, petite Inspire 2 and its upmarket sibling the Fitbit Luxe. The trim Charge 5 has all the features a fitness tracker needs to less outlay than an Apple Watch. 

Conversely, all Apple Watches look roundly similar aside from how much of the front is covered by screen. There’s the lavish one, the more affordable one, and the old one: Watch Series 7, Watch SE and Watch Series 3. 

Like that look? The Fitbit Versa and Sense watches get much closer to the Apple Watch style. However, even these last significantly longer than Apple’s watches off a charge. Stamina varies between models, but at least 4-6 days is the norm for Fitbit, compared to roughly a day or so with an Apple Watch. 

This makes Fitbits better for sleep tracking, and Fitbit probably still has the best sleep tracking software on the market right now (apart from maybe the Oura ring). However, to get the most out of a Fitbit you’ll need a Premium subscription ($9.99/month). This offers additional stats and proper longer-term health metrics, as well as loads of workouts and mindfulness sessions. 

An Apple Watch, regardless of the model you get, will have a better heart rate sensor than a Fitbit’s. Even the best Fitbit Versa 3 and Sense trackers aren’t close to Apple’s for reliability and accuracy. 

The Apple Watch also has the best app ecosystem of any watch. Want apps for third-part platforms, yoga tutorials or mindfulness exercises? Apple can’t be beaten in this area. 

Apple Fitness+, the equivalent to Fitbit Premium, is also more high-end than its Fitbit rival, packed with loads of high-quality video classes. 

If the Apple Watch had Fitbit’s battery life, this would be a fairly clean sweep for Apple. But it doesn’t, and many will find a Fitbit easier to get along with longer-term. 

(Image credit: Future/Lloyd Coombes)

What is a fitness tracker good for

Back in the early days a fitness tracker was a step counter. Iconic models like the Fitbit Zip and Ultra would attach to your shorts or jeans, not your wrist. 

Today, trackers can do a lot more, but they still count your steps. Most will measure your heart rate 24/7: handy for exercise, and your resting heart rate is a decent fitness and health indicator, as explored in a BMC Cardiovascular Disorders study published in 2020.

"Fitness trackers have many useful features and have helped myself and my clients with data collection you can then use to make better fitness decisions," said Kennedy. "Most fitness trackers track number of steps taken, heart rate, and sleep patterns. Some also have connected apps that allow you track your overall progress, set goals as well as offer guidelines to help you achieve your fitness goals."

You can indeed use a fitness tracker to monitor your sleep. And they are better-suited to the job than a smartwatch as trackers often last a week or more between battery charges. 

Some fitness trackers have a feature that lets you sound an alarm on your phone should you misplace it. And nowadays plenty have advanced health and fitness features. 

Any fitness tracker with GPS is a good tool for runners. Many can measure your SpO2 blood oxygen saturation, and a few high-end models have an ECG sensor. There are many stories of this alerting people to atrial fibrillation, a potentially life-saving move. 

Fitness trackers frequently have “stress” monitoring, and guided mindfulness breathing exercises to help you lower that stress level. Even cheap fitness trackers will also relay notifications received, and this can be a useful if you want to spend less time on your phone after work. 

Put the phone in another room, and you can still quickly check for important calls or emails with a quick wrist flick — no chance of getting sucked into YouTube/Facebook/Instagram for an hour. 

"Accountability is much higher when using a fitness tracker as you get the sense personal motivation or if you’re in a group challenge with your friends," added Kennedy. "Trackers can provide feedback to help people monitor their progress toward activity goals and can remind wearers of them. Some trackers come with or integrate with mobile apps that inspire a variety of behavior changes. Ideally, trackers can help users to develop lifestyles that make it easier to integrate physical activity into daily life. The easier it is for the user to get into a lifestyle that works for them the bigger the chance of them achieving their end goal is."

(Image credit: Getty)

Are fitness trackers accurate?

Fitness trackers record a bunch of metrics, each of which introduces accuracy headaches. For step counting, how does a tracker separate steps from hand movements while you work sat at a desk? How can a yoga tracking mode really judge calories burnt when it does not know your muscle tension or perhaps even the positions you adopt?

The best fitness trackers now offer good reliability in a few crucial areas, though, heart rate and location — which look at the distances you run or walk. 

We find Apple Watches and some of the latest Garmin watches, like the Fenix 7, are top-tier performers for heart rate tracking. Apple led the pack for years, but others are starting to catch up. A 2019 study published in the Journal of Medical Internet Research found the Apple Watch offered “clinically acceptable accuracy” for HR tracking during exercise, a higher standard than it might sound — and that was for an old Apple Watch variant. However, it also found the  watch overestimated calories burnt. 

Almost all fitness trackers with GPS will provide fairly good distance stats, particularly if you give them time to lock-on properly before starting your session. 

A lot of other trackers still struggle a little with heart rate readings, though. Interval training and very high exertion in general can be problematic, although in truth this is not a huge issue for most people. Are you really going to pore over the heart rate graph in your tracker’s app?

SpO2 (blood oxygenation) readings can be more problematic, because we find most wearables can throw out highly suspect results at times. You will often get better results on a second or third attempt, but we frequently see readings that suggest we should head straight to the hospital from high-end trackers. 

That said, a study published in Nature concluded the old Apple Watch Series 6 is a reliable enough way to monitor SpO2 in patients with lung conditions. 

The best way to approach a fitness tracker’s stats is to compare your exercise results to your own, from previous sessions. Comparing with a friend’s tracker will expose the way different brands’ algorithms color the results. 

You should also make sure your tracker’s strap is snug and firmly strapped on before starting a tracked exercise session. This will get you the best results from the heart rate sensor.

(Image credit: Getty)

Can fitness trackers measure blood pressure?

Right now there’s only one mainstream consumer wearable that has true standalone blood pressure monitoring, the Huawei Watch D. And it is not widely available. 

Samsung has offered blood pressure readings in its top watches since 2020’s Galaxy Watch 3. However, the feature is only unlocked in certain countries/markets, and is much more limited than the Huawei Watch D’s version. 

Where the Huawei Watch D adopts the method used by blood pressure cuffs with a specialist strap that inflates, the Galaxy Watch uses the heart rate reader on the back to evaluate pulse transit time. Fitbit is researching a similar method, using pulse arrival time. 

However, such methods that do not demand bespoke hardware do need to be regularly recalibrated using a traditional blood pressure cuff. Samsung says results should be taken with one every four weeks, for example. 

Rumors of a blood pressure feature for Apple Watches have circulated for a while, but the latest report suggests we won’t see it released until September 2024. However, you can use an Apple Watch to log blood pressure readings taken elsewhere, in the Apple Health app. Apple sells Withings’s BPM Connect smart blood pressure cuff at the Apple Store. 

Blood pressure via a wearable? It’s not quite there yet. And as the Huawei Watch D is expensive, hard to get hold of, and something we have not tested, you are better off with a more traditional cuff-style design for now. 

(Image credit: Getty)

Why is GPS important in fitness trackers?

GPS is arguably the most powerful tool for fitness trackers. It’s why runners, keen walkers and cyclists should make sure their next fitness tracker has it. 

GPS triangulates your position with the help of satellites. One of these satellite arrays is called “GPS”, but today’s best watches also support others like GLONASS and Galileo. Each of these satellite arrays is maintained by a different country, or set of countries. 

By tracking your location, fitness trackers can produce maps of your runs, hikes and rides. These make historical records much more useful, so you can actually remember which workout an entry refers to. 

Accurate distance data is also important because it affects so many other readings. If the recorded distance is too low, the tracker will think you are slower than you are. And this in turn could affect fitness metrics like VO2 Max. It works the other way around too, of course — too long a recorded distance and the tracker will say you are faster than you really are.

We always recommend a full GPS watch to runners in particular, but there is a second type of GPS. It’s Connected GPS. This is where the tracker does not have its own GPS chip, but can take GPS data from your phone, over Bluetooth. 

Many cheaper trackers without GPS have Connected GPS. And if you plan on running with your phone anyway, to listen to music or podcasts, it’s a decent stand-in. 

With no GPS at all, your tracker has to extrapolate distance using its motion sensors. It can count your strides and evaluate the pace of them to differentiate between running and walking. This can work pretty well with a good algorithm running behind the scenes, but GPS is better. And considering how cheap Connected GPS wearables get, we don’t recommend entirely non-GPS watches to many folks these days. 

Our Expert

Nathan Kennedy

Nathan Kennedy is a fully qualified personal trainer, online coach and fitness expert. He has been part of the fitness industry since 2005, going to the gym and competing in bodybuilding shows. Kennedy has been a personal trainer for 6 years. He is also a representative for sports nutrition brand Bio-Synergy 

Since 2015, we’ve been running, walking, swimming, cycling, sleeping, and basically living with 46 different fitness trackers day and night, to assess their accuracy, ease of use, and comfort. Although no tracker perfectly recorded every metric we tested, we found that the simply designed yet feature-packed Fitbit Inspire 3 is the best option for most people who want to monitor their activities, with metrics like distance traveled, step count, heart rate, and estimated calories burned.

Wrist-worn fitness trackers that can monitor your steps and heart rate were once seen as cutting-edge devices. Now these wearables are becoming more high-tech with each release, equipped with features like personalized workout programs and the advertised ability to monitor stress or sleep quality.

The Apple Watch SE delivers some of the most precise readouts and—with a mobile plan—can be used for calls and messaging. But its battery life is much shorter than that of our Fitbit picks.

The latest version of the Charge series continues a tradition of accurate activity tracking, but many of the new additions require Google integration.

This easy-to-use tracker is comfortable to wear all day and provides accurate measurements, without too much clutter on the homescreen.

We walked, jogged, and ran with each fitness tracker to see how well it documented workout data.

We wore each device for two days straight, comparing step-count data to that of a pedometer we know to be precise.

The Fitbit Inspire 3 was the most accurate fitness tracker for step count and near the top of the rankings for every other test we performed. The touchscreen display is only 1.5 inches tall but is simple to navigate, thanks to its sharp colors and easily readable text and icons. The thin, half-inch band doesn’t feel clunky during workouts or everyday use, and the Inspire 3 weighs just 0.32 ounce—lighter than a typical USB flash drive.

Fitbit has a free app where you can connect with other Fitbit users, log information to learn about stress management, and dig deeper into data such as heart-rate history (a premium version of the app costs $10 per month or $80 per year) and offers access to apps like Calm for sleep and meditation). The Inspire 3’s battery is advertised as lasting 10 days before charging, although we found it to come in a fair bit short of that mark.

Battery life: up to 10 days
Water resistance: yes, for up to 50 meters
GPS: when connected to a phone

The Fitbit Charge 6 offers a few upgrades from the Charge 5 , which we previously recommended as a runner-up pick. The most notable upgrade is a haptic side button that allows for easier screen navigation than swiping on the touchscreen (which, we found, sometimes isn’t responsive). The Charge 6 also has built-in GPS, which the Inspire 3 doesn’t have, in addition to access to Google Maps, Google Wallet, and YouTube Music (with subscription). But when it comes to tracking distance, the Inspire 3 performed better in our tests.

Battery life: up to seven days
Water resistance: yes, for up to 50 meters
GPS: built in

The second-generation Apple Watch SE has a vibrant, clear display and the best intuitive touchscreen of the devices we tested. Even if you’re not connected to an iPhone, you can take advantage of a large library of apps. Performance-wise, the Apple Watch SE—also our budget pick smartwatch for iPhone users—accurately measured heart rate, steps, and distance. But for people who want to go on a run and just track, say, their pace and distance, the Apple Watch SE might be overkill, especially given its higher price and limited battery life.

Battery life: up to 18 hours
Water resistance: yes, up to 50 meters
GPS: built in