🔗 Share this article

There's a nervous excitement. I can see the frosty air emanating from my rivals as they do the "starting line" jiggle on the beginning point.

A quick movement of the hips.

I'm lined up for my local weekly parkrun event and I'm serious. Three, two, one...

Oh, hang on. I need to start my device. So does the runner next to me.

The person behind us expresses impatience. I refuse to go until… done! Connection established, and I'm running.

During the scramble, it's challenging to spot a wrist without a smartwatch on it. And this isn't only us runners who use them.

This is a thriving, multi-billion dollar market. Names like Apple Watch are prevalent, all offering an broad array of different models to cater to a range of lifestyles. According to how high tech the model you choose, price tags can range from an affordable sum to thousands of pounds.

"It makes me crazy, I can't stop checking."

"It comforts me… It's like a companion encouraging me."

"Please don't notify me I've experienced a restless night."

A small sample of the responses people have shared from fellow smartwatch wearers when I ask what they think of theirs.

A Sea of Statistics

My thoughts on mine? Currently, annoying. It's reporting I'm not hitting my target, causing me to question whether the trees along my route are blocking my satellite signal.

Countless individuals of us attach these small gadgets onto our arms and use them 24/7, seemingly comfortable with the fact they're constantly tracking us.

A distant memory are the days when we depended on them solely to give us an rough count of our daily steps. Currently, they can measure our nightly rest, heart rate, oxygen saturation, our recovery score.

It's a challenge to find a physical metric they aren't designed to measure.

But can they do what they say they do? And are the data points we scrutinise a faithful picture of our actual health? Do they enhance our mental and physical wellbeing, or do the multitude of readings and cheerleading alerts just increase our everyday anxiety?

A Complicated Bond

"I find myself getting a quite preoccupied with mine," a wearer reveals.

While she values how her device records her workouts, she finds some of its other functions "excessive" at times - a feeling first discovered during a significant period.

Until she found out she could put it into a specific mode, her smartwatch constantly alerted her she was being insufficiently energetic enough. Later on, the watch frequently reports her she's had a poor sleep score.

"I've got a infant, I don't need to be told I've not slept," she says. "I know that only too well."

Why doesn't she just take it off?

"It's possible, I suppose, but I'm in this push-pull dynamic with it," she continues. "I love it for its workout tracking, I just wonder whether all the other things it can now do is possibly too much for me."

How Do They Work?

Different brands of smartwatch has its own unique way of monitoring your health metrics and processing your data, but the vast bulk use optical sensors on the back of the watch.

They typically shine tiny, coloured LED lights onto your arm which can detect capillary action, recording your pulse rate. More advanced devices analyse changes in the bioimpedance that flows through the skin to gauge your nervous system activity.

A Fine Balance

A data scientist says that for most people for smartwatches, it's a "difficult line" - while the continuously improving tech could actually prevent illness, "spotting abnormalities 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 carry out tests like heart rhythm analysis, which regularly monitor how healthy the heart is. They can notify if someone is experiencing atrial fibrillation (AF), where there is erratic electrical activity in the heart causing an irregular heartbeat.

This does not mean someone is on the verge of a cardiac event, but it can give an advance notice they might be more susceptible of a heart problem in the years to come.

But how to interpret these numbers is complicated. The expert fears that as further capabilities are added, people may find it hard to fully comprehend their data.

"I'm not entirely convinced that having the capacity to monitor so much data is such a positive development," he says.

A health researcher focusing on wearable tech echoes this sentiment. A study into the impact of wearable tech on a specific group of cardiovascular patients suggested a minority of those who were given devices to monitor their condition experienced increased anxiety and were "far more likely to use medical services".

She identified a pattern with her patients - they saw a concerning reading on their watch. They grew concerned. Their pulse increased. They got increasingly anxious. They looked a second time, and their anxiety increased again.

"If we see stats about ourselves that we lack context for then, naturally, we are going to seek clarification," the psychologist says. "We look, we re-check - it becomes a self-fulfilling prophecy."