🔗 Share this article

There's a feeling of anticipation. I can see the frosty air coming from my competitors as they do the "pre-race" wiggle on the beginning point.

A quick twitch of the hips.

I'm lined up for my local weekly parkrun event and I mean business. The countdown begins...

Hold on. I need to start my tracker. The same goes for the person next to me.

The person behind us expresses impatience. I won't start until… done! Signal acquired, I'm off.

During the scramble, it's difficult to find a wrist without a fitness tracker on it. And it's not just us runners who use them.

It's a explosive, multi-billion pound market. Brands like Garmin are prevalent, featuring an wide array of different versions to suit a spectrum of budgets. According to how advanced the model you select, costs can vary between £100 to thousands of pounds.

"It makes me crazy, it's impossible to stop checking."

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

"I wish it wouldn't say I've experienced a restless night."

A handful of the comments I've received from like-minded tracker enthusiasts when I question what they feel about theirs.

The Data Dilemma

My feelings on mine? Currently, annoying. It's reporting my speed is wrong, causing me to question whether the overhead branches along my route are disrupting my location tracking.

A vast number of us attach these compact devices onto our arms and keep them on 24/7, seemingly at ease with the fact they're constantly monitoring us.

A distant memory are the days when we used them solely to give us an idea of our pedometer reading. Today, they can track our nightly rest, blood pressure, oxygen saturation, our VO2 max.

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

But are they able to do what they advertise? And are the numbers we obsess over a true reflection of our actual health? Do they boost our overall health, or do the plethora of readings and constant notifications just increase our sense of overwhelm?

A Love-Hate Relationship

"I become a a little fixated with mine," an individual confesses.

While she appreciates how her device tracks her runs, she finds some of its other features "daunting" at times - a feeling first discovered during a major life event.

Prior to discovering she could put it into a specific mode, her smartwatch kept telling her she was failing to be energetic enough. Later on, the watch frequently reports her she's had a bad night's sleep.

"I've got a infant, it's unnecessary for me to be notified I'm tired," 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 love-hate relationship with it," she continues. "I love it for its fitness insights, but I'm unsure whether all the other things it can now do is maybe overkill for me."

How Do They Work?

Different brands of smartwatch has its own unique way of tracking your vitals and processing your data, but the majority use optical sensors on the reverse of the watch.

They typically emit tiny, coloured LED lights onto your wrist which can monitor capillary action, detecting your pulse rate. More advanced devices measure changes in the electrical current that passes over the skin to get an idea of your stress levels.

Expert Perspectives

A professor says that in general for smartwatches, it's a "difficult line" - while the ever-evolving tech could potentially aid early diagnosis, "spotting abnormalities before we show symptoms", it could also turn us watch wearers into the "concerned but fine".

He points out that the most advanced wearables can carry out tests like medical-grade monitoring, which continuously monitor how stable the heart is. They can flag if someone is experiencing atrial fibrillation (AF), where there is irregular signals in the heart causing an arrhythmia.

This does not automatically signal someone is on the verge of 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 readings is not straightforward. The expert concerns that as more functions are added, people may find it hard to fully understand their data.

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

A professor specialising in cardiology concurs. Research into the effect of wearable tech on a set of individuals with health issues suggested a significant portion of those who were given devices to monitor their condition experienced increased anxiety and were "far more likely to use doctor's time".

She identified a pattern with her patients - they noticed a worrying figure on their watch. They became worried. Their pulse increased. They got more worried. They re-examined the data, and their anxiety increased again.

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