🔗 Share this article

An atmosphere of building tension. I can see the frosty air coming from my rivals as they perform the "starting line" wiggle on the starting line.

A rapid movement of the hips.

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

Hold on. I have to start my device. As does the person next to me.

The person behind us expresses impatience. I won't start until… there! Signal acquired, and I'm running.

In the mele, it's challenging to spot a person without a smartwatch on it. And this isn't only us runners who rely on them.

We're witnessing a booming, multi-billion dollar industry. Companies like Garmin dominate, each with an wide array of different models to fit a range of lifestyles. Based on how high tech the device you choose, costs can start from an affordable sum to a significant investment.

"It makes me crazy, it's impossible to switch off."

"It reassures me… It acts as a supporter guiding me."

"Please don't notify me about a bad night's sleep."

Just some of the responses I've received from like-minded smartwatch wearers when I ask what they think of theirs.

A Sea of Statistics

My current opinion on my own device? Right now, annoying. It's indicating I'm not hitting my target, making me wonder whether the trees I'm passing under are blocking my GPS connection.

Millions of us fasten these small devices onto our wrists and keep them on 24/7, ostensibly unconcerned with the fact they're perpetually recording us.

Long past are the days when we relied on them only to give us an idea of our step count. Now, they can measure our sleep patterns, stress levels, oxygen saturation, our VO2 max.

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

But are they able to do what they claim to do? And are the statistics we analyse a true reflection of reality? Do they improve our overall health, or do the multitude of readings and motivational messages just add to our everyday anxiety?

A Complicated Bond

"I become a bit obsessed with mine," an individual admits.

While she appreciates how her device monitors her exercise, she finds some of its other capabilities "excessive" at times - a feeling first discovered during a major life event.

Before she realised she could put it into a specific mode, her smartwatch constantly alerted her she was being insufficiently energetic enough. Later on, the watch insists her she's had a bad night's sleep.

"I am caring for a infant, it's unnecessary for me to be notified I've not slept," she says. "I'm acutely aware perfectly well."

Is it not possible to just remove it?

"I could, theoretically, but I'm in this love-hate relationship with it," she continues. "I appreciate it for its fitness insights, but I'm unsure whether the additional features it can now do is possibly excessive for me."

How Do They Work?

Each model of smartwatch has its own proprietary way of tracking your health metrics and processing your data, but the most use optical sensors on the back of the watch.

They usually shine minute LED lights onto your wrist which can detect pulsation, identifying your BPM. Sophisticated devices detect changes in the bioimpedance that runs through the skin to gauge your stress levels.

A Fine Balance

A data scientist says that overall for smartwatches, it's a "difficult line" - while the ever-evolving tech could realistically save lives, "detecting disease before we feel unwell", it could also turn us watch wearers into the "worried well".

He points out that newer wearables can perform tests like medical-grade monitoring, which regularly monitor how normal the heart is. They can alert if someone is experiencing an irregular rhythm, where there is irregular impulses in the heart causing an arrhythmia.

This does not automatically signal someone is on the verge of a cardiac event, but it can give an early warning they might be more vulnerable of a heart problem in the long term.

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

"I'm not entirely convinced that the ability to monitor so many metrics is such a beneficial thing," he says.

A health researcher specialising in wearable tech echoes this sentiment. Her work into the effect of wearable tech on a specific group of individuals with health issues suggested a minority of those who were given devices to monitor their cardiac function experienced heightened worry and were "had a higher tendency to use doctor's time".

She noted a cycle with her patients - they noticed a worrying figure on their watch. They grew concerned. Their heart rate went up. They got increasingly anxious. They checked again, and their heart rate rose further.

"Upon viewing data about ourselves that we can't properly interpret then, naturally, we are going to become concerned," the psychologist says. "We monitor, we check again - it becomes a self-fulfilling prophecy."