Do fitness trackers really work?

Fitness Trackers 1

When it comes to wearable fitness tech, it seems just about everyone has one. From Apple watches to Garmin Forerunners and Fitbits to WHOOP bands, activity tracking has become a competitive sport. But as fitness trackers and health data become ever more prolific, are we actually getting healthier?

No, according to recent research. In fact, a study of 800 test subjects found that after 12 months, fitness trackers had no effect on the subjects’ overall health and fitness – even when combined with a financial incentive. 

A study in the Journal of the American Medical Association found users without fitness trackers lost more weight than those who wore one. And a 2016 study of 9,592 survey respondents found 30 per cent of users tossed their tracker because they didn’t find it useful or got bored with it. 

Researchers from Deakin University report even higher abandonment rates: 25 to 50 per cent of adults ditch their devices six months after purchase.

And yet, sales of fitness trackers continue to skyrocket, with global revenue from fitness wearables tipped to top USD $3.3 billion by 2022.

How accurate are fitness trackers?

Researchers from the University of Wisconsin concluded that trackers are less accurate for energy expenditure than for counting steps. However, overall, the ‘validity data for wearables are fairly encouraging’. 

The study noted that accuracy drops at very slow walking speeds and during running, and that differing algorithms between brands and even models within the same brand can impact accuracy.

Can wearing activity trackers spark behavioural change?

A study in the Journal for Nurse Practitioners noted that while accuracy of trackers is not absolute, fitness trackers are ‘sufficiently accurate to provide patients with the feedback they need to set goals and monitor progress’. 

In short, goal setting and progression are the true benefits of wearables. Not relying on your daily step or calorie count as 100 per cent accurate. 

When to use activity trackers

Fitness trackers using a GPS can be very accurate, says David Cunningham, Triathlon Coach with T-Rex Triathlon Club on the Gold Coast. 

‘If used properly, smart watches such as Garmin are very accurate,’ he says. But if you start moving before the satellite is picked up by the watch, the data will be off. Trees can affect the GPS reading in trail running and ‘…we’ve found variations in distance measured in open water swimming – up to 10 per cent discrepancy,’ adds Cunningham. 

Daniel Robson-Petch, Director of Resistance Sports Science, agrees: ‘We have found they are generally reliable for pace, splits and sleep. However, calories burned requires greater work as it differs depending on the type of exercise.’

And if your daily activity comes more from incidental movement than structured exercise, your tracker won’t necessarily reflect your output. 

‘An important gap in trackers’ technology is the inability to capture brief (one to three minutes long) bouts of vigorous physical activity done during activities of daily living. For example, stair climbing or carrying shopping bags,’ says Professor Emmanuel Stamatakis from the University of Sydney.  

‘When repeated several times across the day, such a pattern could potentially improve and maintain fitness. It’s a missed opportunity for wearable devices,’ he says.

What about the accuracy of sleep trackers?

‘Sleep trackers typically measure body movement, heart rate and/or respiration rate,’ says Professor Philip de Chazal from the University of Sydney. ‘Based on patterns in these signals, mathematical algorithms try to estimate when you are awake or in different stages of sleep during your sleep period.

‘The ideal sleep period contains a mixture of light sleep, deep sleep and REM (or dreaming) sleep. Wearables try to measure the amount of time you spend in these sleep states. 

‘By comparing your values to the ideal values, wearables then provide a measure of how close you are to the ideal values and therefore provide a measure of your sleep quality.’

Why is sleep quality important? ‘Sleep is an essential function that allows your body and mind to recharge, leaving you refreshed and alert when you wake up. Healthy sleep also helps the body remain healthy and fight off diseases. A healthy sleep is having the right amount (quantity) of good quality sleep,’ says de Chazal.

And while fitness trackers are notoriously inaccurate in measuring true sleep quality, there is hope on the horizon. Researchers from Michigan Medicine reported a new algorithm that tracks sleep using heart rate and acceleration, with an accuracy of 90 per cent in determining sleep from wakefulness.

So should you wear a fitness tracker?

Yes, say our expert panel.

‘For previously inactive people who start to exercise, perceived exertion is the best guide,’ says Stamatakis. 

‘Then as they become more experienced and they understand better their body’s responses to exercise, trackers can be a useful tool for increasing intensity in line with progressive workload principles.’

While his athletes’ workouts, output and programs are synced via smart watches and software, Cunningham says sometimes RPE (rate of perceived exertion) is just as useful as your tracker. For swim sets where you can’t look at your watch, perceived effort is your best guide, alongside lap times. 

‘Our athletes use fitness trackers primarily for distance or kilometres per week. We use them as a practical way of calculating load and RPE which decreases our athletes’ chance of injury,’ says Robson-Petch. 

‘However, we don’t recommend obsessing over the data. There are many more factors that require our athletes’ attention, such as fatigue scores, nutrition, recovery, high speed meters and strength training.’

It’s the slippery slope into monitoring our every move which has led to a rise in obsessively tracking our daily activity – now known as health anxiety.

When tracking becomes obsession

This phenomenon, driven by the availability of health data from your tracker, can cause such excessive monitoring that it might be interfering with your mental health, work and relationships.

In fact, when it comes to sleep tracking, researchers from Rush University Medical School in Chicago even coined a name for it: orthosomnia or the obsessive pursuit of the perfect sleep.

Some athletes may be at risk of overreaching or overtraining if they stop listening to their bodies and instead chase the numbers on their watch. 

‘And there’s no point tracking data without a structured plan,’ adds Cunningham. 

Robson-Petch agrees: ‘Just because you are feeling good and believe you are fine to run another few kilometres, we need to think about how that will affect skills and strength training. A well written plan has much more value over hitting precise measurements.’

For those stressing about sleep quality, de Chazal notes a flipside of tracking: ‘Some people find out they sleep better than they think and then stop worrying about their sleep!’

How to get the most from your tracker and what to look for:

  • Use your tracker to chart trends: Don’t get hung up on the intricate detail of one run or one night’s sleep. 
  • Choose a user-friendly interface: ‘Sleep trackers are probably most useful when looking at changes in your sleep patterns over time,’ says de Chazal. ‘So, look at the supplied software/web interface to see how easy it is to track and compare your sleep over multiple nights.’ Same goes for your activity data.
  • Choose one method and stick with it: ‘There’s a discrepancy between wrist measurement and chest strap heart rate monitors,’ says Cunningham, noting chest straps are far more accurate than watches.
  • Consider time of day and climate: ‘In hot or humid environments, your heart rate can be ten to 15 beats higher in the middle of the day than in the morning,’ says Cunningham.
  • Know what you are tracking for: If you’re a runner, you don’t need all the bells and whistles of a multisport watch. If a pumping playlist is your jam, look for a watch that supports music. ‘We look for heart rate, stopwatch settings, distance travelled and splits,’ says Robson-Petch. 
  • Think about battery life: ‘Decide if you want a wearable or non-wearable tracker,’ suggests de Chazal. ‘For wearables, look at how often they need to be charged up.’

Benefits of training tech-free

A study of Fitbit wearers found that 60 per cent felt their daily activities were controlled by their device, and 30 per cent reported their gadget made them feel ‘guilty’. So, if running unplugged gives you greater joy, ditch the devices. 

In fact, some coaches recommend training tech-free to tune into your RPE and your body’s response to high exertion. ‘Perceived effort is still one of the best measures – if you don’t train without the tech, you won’t know what your perceived effort is,’ says Cunningham. 

The mental focus of training without watches is an added benefit, says Robson-Petch: ‘Many of our athletes train tech-free. There are no distractions and their thoughts are only on what is ahead of them. This can be a great mental release, which we know is just as important as physical recovery.’


STRONG Australia’s Editor-in-Chief, Katelyn Swallow, tested a few of the fitness trackers on the Australian market, with the newly updated Suunto 7 smart sportwatch coming up trumps.

Perfect customer: Sports enthusiasts, offering over 70 sports modes to track everything from running, cycling and skiing to surfing.

What we love:

  • This GPS-enabled tracker is shock proof, water-proof and dirt-proof and oh so pretty. Wear it out or wear it in the gym – the rose gold colour and beautiful watch detailing is guaranteed to impress. 
  • The app is also reasonably easy to use, allowing you to set goals and track steps and calories, that are also visible on the watch itself. 
  • The new heat map function lets you discover the local tracks and trails where there’s less foot traffic – good news for those still social distancing!

What we don’t love as much:

  • Battery time. With the GPS mode enabled, you get about 12 hours before needing to recharge. So it’s no good for those wanting to track sleep.
  • The watch face is a statement piece and not exactly small – easy to bump into things!

Where to get it:
$599.99 from the Suunto website

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