I'm a fitness instructor and here's why your wearable is a waste of money

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As a fitness professional with over 30 years' experience, I’ve seen many trends come and go. From vibrating belts to Jane Fonda’s aerobics, the combat-inspired Tae Bo and Zumba, there has been a constant flow of gadgets and workouts that have promised to deliver. While all burned brightly at first, most saw interest dwindle. However, there is one fitness trend which seems here to stay.

Fitness wearables give an insight into lots of metrics – this can be both interesting and helpful. As someone who recently binned my own tracker, I feel that constant monitoring could be problematic on a number of levels. So, what are they, what do they do and more importantly, should you join the 23% of Brits and 21% of Americans who wear one? Or is it just another fitness craze to steer clear of…

Person with fitness tracking watch and mobile phone

The history

The popularity of fitness trackers has grown exponentially in the last few years, becoming an indispensable tool for many fitness enthusiasts. One report indicates market size is around £42 billion with potential to grow to £100 billion by 2030. I suspect that on seeing the size of those numbers, the Swiss horologist, Abraham-Louis Perrelet who is credited with inventing the first step counter in 1780, might take a sharp inhale – which, of course, could be measured on many of today’s devices.

From the first commercial heart rate monitor used in Japan in 1965, to the launch of Fitbit in 2007 and the birth of the Apple Watch in 2015, we have certainly seen changes. Gadgets such as smartwatches – which make up nearly 32 per cent of all wearable device purchases – can not only monitor aspects of fitness performance, but also tell the time, show notifications, play music and make calls.

The hardware

Wrist-worn devices are the most popular, hence the wide range that includes Fitbit, Whoop and the Apple Watch, with Samsung, Garmin and Huawei offering similar. If you prefer to go more discreet, the less bulky rings from Oura, RingConn and Ultrahuman are a good alternative. Even more low-profile are earphone trackers that give the same data as wrist and finger devices but can be more accurate when measuring blood pressure, heart rate and body temperature.

Using a combination of built-in tools, like optical sensors, data is gathered and then presented. The metrics available has grown considerably since that first step counter in the late 18th century and includes distance, calories, heart rate, sleep, blood oxygen level, heart rate variability and blood pressure. A new device being used by the US army measures sweat composition, fluid loss, skin temperature and more to highlight early signs of fatigue.

It’s easy to see how this data can be useful for elite athletes to improve their performance by ensuring training and recovery sessions are effective, but what about those of us who are not training for the next Olympics?

Do fitness trackers actually work?

Researchers at McMaster University found that while the Fitbit Charge is a fairly accurate step counter and the Apple Watch is a good indicator of heart rate, none of the devices tested, which included Garmin and Nike products, were reliable when it came to energy expenditure. This is worrying if you’re looking at calories in vs calories burned.

Although it would be great to know you’ve increased your step count, if that was through a leisurely stroll in the park, it won’t impact your fitness in the same way completing those 200 steps on hill sprints would. This is why some trackers measure strain rather than steps. Although there isn’t agreement across brands as to precisely what this metric means and how it’s calculated.

In terms of weight loss, one study by the Journal of American Medicine Association asked 500 overweight individuals to diet and exercise but gave trackers to only half the group. Results showed that, over an 18-month period, the control group lost an average of 13lbs while those wearing the devices only lost an average of 8lbs.

Wearables suppliers claim that an awareness of your activity enhances motivation to exercise and this is true initially, as the brain reward pathway releases dopamine when we log our daily numbers. However, repeated exposure to this stimulus can lead to a decrease in the system's sensitivity so the effect wears off. Additionally, after a few days of seeing your step count break the 10,000 barrier due to your new ‘get off the bus three stops early’ or ‘walk to the shops’ routine, you know the change is doing you good so the tracker becomes redundant.

In terms of sleep, it’s well-established that alcohol, caffeine, stress and exercising too close to bedtime can negatively impact sleep quality, so is it of any value to know if your sleep score is five per cent better or worse than yesterday?

What nobody tells you about fitness trackers

Fitness trackers collect various health measurements, some of which could be sensitive information so, naturally, there may be concerns about data security.

A study of female health monitoring apps by King’s College London and University College London found that 35 per cent of them mention some level of third-party sharing in their privacy policies.

Goal-setting is a great tool for your fitness journey but if you become obsessed with certain metrics and feel pressure to hit your targets, this could lead to increased anxiety, according to a study published in the American Journal of Health Education. In a worst-case scenario, this could result in compensatory behaviours, such as over-training the next day or drastically reducing food intake.

There is a risk that users could become driven by their statistics, for example, constantly repeating that HIIT workout that shifted calories, rather than striving to improve general health in a balanced way.

Some research highlights a worrying dependency on trackers for some participants, with motivation to exercise significantly reduced if the device wasn’t available. This was found to be more common with those who were pursuing aesthetic goals, compared to those who exercised for enjoyment.

Users are encouraged to share their metrics with the aim of building a supportive community. However, research has shown that regular comparison with others could negatively impact self-esteem.

If you wear your wristband in a slightly different position or a little looser than usual, this can affect readings, an effect that could be exacerbated if you applied sunscreen or insect repellant prior to your outdoor workout. This then makes it difficult to compare your performance and achievements in different workouts.

Surprisingly, paying a higher price doesn’t guarantee better quality according to Loughborough University's National Centre for Sports and Exercise Medicine. For some of the measurements tested, the more expensive fitness trackers were actually less accurate than cheaper alternatives, for example with step count.

A man on a running track checking his sports watch

The takeaways

It’s true, there are stories about wearables saving lives by identifying atrial fibrillation. However, the British Heart Foundation warns that results can be affected by the position of the tracker, plus it can be inaccurate compared to one used in a medical setting. So, whether your tracker sends an alert, you feel symptoms or you just haven’t had a check up for a while, contact your medical professional.

During workouts, you could try monitoring the intensity using the rate of perceived exertion, a technique developed by Swedish scientist Gunnar Borg. This rates physical output from zero to 10 and can be used to achieve results.

When it comes to recovery, you don’t need a statistic to tell you how you feel after yesterday’s workout. If you pushed it a bit too hard, try a gentle walk, a full-body stretch or massage.

To improve your sleep quality, keep a journal to identify any potential problems, such as diet, bedtime, tech usage and room temperature.

If you don’t know really know what your heart rate variability and blood oxygen levels are, should be or how to change them, then you’re paying for features you don’t use (and most of us don’t need).

Rather than becoming a slave to metrics based around population norms, define what success means to you. You can then monitor your progress by manually recording it. As Leonardo da Vinci once said, “Simplicity is the ultimate sophistication.”

So, are fitness trackers worth it?

Realising you feel energised after a morning workout or noticing you feel calm after taking a moment to breathe helps create an awareness, action, feedback loop that reinforces positive behaviour. This will lead to a sustainable shift towards good long-term health and it’s not essential to quantify it... particularly if it’s done inaccurately!