🔗 Share this article

A sense of nervous excitement. I can see the chilled vapour coming from my competitors as they execute the "pre-race" wiggle on the start line.

A quick movement of the hips.

I'm at my local 5km community parkrun and I mean business. Three, two, one...

Hold on. I need to sort my tracker. The same goes for the guy beside me.

The person in the line sighs. I won't start until… done! Connection established, I'm off.

Amidst the crowd, it's difficult to find a arm without a wearable on it. And it's not just us runners who wear them.

It's a explosive, multi-billion pound sector. Companies like Apple Watch lead the market, all offering an broad range of various versions to cater to a range of budgets. Based on how high tech the watch you go for, price tags can start from a hundred pounds to a significant investment.

"I find it infuriating, I can't switch off."

"It reassures me… It's like a companion guiding me."

"Stop telling me about a bad night's sleep."

A small sample of the responses I've received from other device users when I question what they think of theirs.

The Monitoring Conundrum

My thoughts on mine? At this moment, irritating. It's telling me my speed is wrong, leading me to doubt whether the overhead branches I'm running below are blocking my GPS connection.

Countless individuals of us fasten these little devices onto our arms and wear them all day and night, apparently at ease with the fact they're perpetually monitoring us.

Gone are the days when we depended on them exclusively to give us an idea of our step count. Now, they can measure our sleep quality, blood pressure, heart rate variability (HRV), our recovery score.

It's a challenge to find a health indicator they aren't designed to measure.

But do they do what they advertise? And are the numbers we obsess over a true reflection of the truth? Do they enhance our overall health, or do the plethora of metrics and motivational messages just contribute to our sense of overwhelm?

A Complicated Bond

"I do get a bit preoccupied with mine," a wearer admits.

While she values how her device tracks her exercise, she finds some of its other capabilities "overwhelming" at times - a feeling initially realised during a significant period.

Until she found out she could adjust the settings, her smartwatch repeatedly informed her she was not being energetic enough. Now, the watch keeps telling her she's had a bad night's sleep.

"I am caring for a six-month old, there's no point to be informed I've not slept," she says. "I know that all too clearly."

Couldn't she just take it off?

"I suppose I could, perhaps, but I've got this love-hate relationship with it," she says. "I value it for its workout tracking, I just wonder whether the myriad other functions it can now do is perhaps overkill for me."

How Do They Work?

Every device of smartwatch has its own novel way of tracking your bodily functions and analysing your data, but the majority use detectors on the underside of the watch.

They typically emit tiny, coloured LED lights onto your wrist which can detect blood flow, recording your BPM. Sophisticated devices measure changes in the electrical current that passes over the skin to assess your nervous system activity.

The Professional Viewpoint

A data scientist says that overall for smartwatches, it's a "fine balance" - while the ever-evolving tech could realistically prevent illness, "detecting disease before we show symptoms", it could also turn us device users into the "anxious healthy".

He points out that some of the latest wearables can conduct tests like medical-grade monitoring, which constantly monitor how stable the heart is. They can alert if someone is experiencing atrial fibrillation (AF), where there is abnormal electrical activity in the heart causing an uneven pulse.

This does not automatically signal someone is on the verge of a heart attack, but it can give an preliminary indication they might be more susceptible of a blood clot in the future.

But how to interpret these figures is not straightforward. The expert fears that as more functions are introduced, people may struggle to fully contextualise their data.

"I'm not entirely convinced that the ability to monitor so many things is such a positive development," he says.

A professor focusing on patient behaviour concurs. A study into the impact of wearable tech on a cohort of cardiovascular patients suggested a significant portion of those who were given devices to monitor their condition experienced greater stress and were "had a higher tendency to use medical services".

She observed a vicious circle with her patients - they saw a alarming metric on their watch. They became worried. Their BPM rose. They got more worried. They looked a second time, and their reading rose further.

"When people are presented with data about ourselves that we don't really understand then, understandably, we are going to seek clarification," the psychologist says. "We monitor, we check again - it becomes a self-fulfilling prophecy."