🔗 Share this article

An atmosphere of feeling of anticipation. I can see the chilled vapour emanating from my rivals as they perform the "about to run" shuffle on the start line.

A quick twitch of the hips.

I'm at my local weekly parkrun event and I'm focused. Three, two, one...

Hold on. I need to sort my watch. As does the person next to me.

The person waiting tuts. I'm not moving until… yes! Connection established, away I go.

During the scramble, it's hard to spot a wrist without a smartwatch on it. And it's not just us participants who rely on them.

It's a thriving, multi-billion dollar sector. Companies like Garmin lead the market, featuring an extensive selection of different models to cater to a variety of budgets. Based on how feature-packed the model you select, price tags can start from an affordable sum to thousands of pounds.

"It drives me insane, I can't stop checking."

"It provides solace… It acts as a supporter supporting me."

"Stop telling me I've experienced a bad night's sleep."

A handful of the comments I've had from fellow tracker enthusiasts when I inquire what they think of theirs.

A Sea of Statistics

My current opinion on my own device? Right now, frustrating. It's indicating I'm off pace, making me wonder whether the trees along my route are interfering with my location tracking.

Countless individuals of us strap these small monitors onto our arms and keep them on constantly, seemingly comfortable with the fact they're continuously monitoring us.

A distant memory are the days when we depended on them exclusively to give us an rough count of our pedometer reading. Currently, they can measure our nightly rest, blood pressure, glucose levels, our recovery score.

It's difficult to find a bodily function they aren't designed to measure.

But can they do what they say they do? And are the numbers we obsess over a accurate representation of our actual health? Do they boost our daily wellness, or do the plethora of readings and motivational messages just add to our sense of overwhelm?

A Complicated Bond

"I do get a a little obsessed with mine," an individual reveals.

While she loves how her device tracks her runs, she finds some of its other features "overwhelming" at times - a feeling initially realised during a pregnancy.

Prior to discovering she could change its configuration, her smartwatch repeatedly informed her she was being insufficiently energetic enough. In a new phase, the watch keeps telling her she's had a bad night's sleep.

"I have a six-month old, there's no point to be informed I'm tired," she says. "I know that only too well."

Couldn't she just remove it?

"I suppose I could, perhaps, but I've got this push-pull dynamic with it," she explains. "I value it for its fitness insights, but I'm unsure whether the myriad other functions it can now do is possibly too much for me."

How Do They Work?

Each model of smartwatch has its own proprietary way of tracking your health metrics and analysing your data, but the vast bulk use detectors on the reverse of the watch.

They usually project minute LED lights onto your wrist which can detect pulsation, identifying your heartbeat. Sophisticated devices detect changes in the skin conductance that flows through the skin to get an idea of your nervous system activity.

A Fine Balance

A professor says that in general for smartwatches, it's a "fine balance" - while the rapidly advancing tech could realistically save lives, "identifying issues before we show symptoms", it could also turn us watch wearers into the "worried well".

He points out that newer wearables can conduct tests like heart rhythm analysis, which regularly monitor how healthy the heart is. They can alert if someone is experiencing an irregular rhythm, where there is irregular electrical activity in the heart causing an arrhythmia.

This does not automatically signal someone is imminently going to suffer a heart attack, but it can give an advance notice they might be more at risk of a blood clot in the long term.

But how to interpret these figures is complex. The expert concerns that as additional features are introduced, people may not be able to fully contextualise their data.

"I have some doubts that having the capacity to monitor so many things is such a good idea," he says.

A professor specialising in wearable tech echoes this sentiment. A study into the influence of wearable tech on a set of cardiovascular patients suggested a significant portion of those who were given devices to monitor their cardiac function experienced increased anxiety and were "had a higher tendency to use doctor's time".

She identified a cycle with her patients - they saw a alarming metric on their watch. They grew concerned. Their BPM went up. They got even more concerned. They re-examined the data, and their heart rate increased again.

"Upon viewing data about ourselves that we lack context for then, of course, we are going to want to know more," the psychologist says. "We look, we check again - it becomes a self-fulfilling prophecy."