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There's a feeling of anticipation. I can see the frosty air emanating from my fellow runners as they do the "starting line" jiggle on the start line.

A swift flick of the hips.

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

Hold on. I have to start my device. So does the runner alongside me.

The person in the line tuts. I refuse to go until… done! Signal acquired, away I go.

During the scramble, it's challenging to see a wrist without a wearable on it. And this isn't only us athletes who rely on them.

This is a explosive, multi-billion dollar industry. Names like Samsung Galaxy dominate, each with an broad array of various devices to cater to a spectrum of budgets. Depending on how advanced the watch you select, price tags can vary between £100 to a small fortune.

"It drives me insane, I'm unable to stop checking."

"It provides solace… It's like a supporter encouraging me."

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

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

The Data Dilemma

My thoughts on my own device? Currently, irritating. It's indicating I'm off pace, causing me to question whether the overhead branches I'm passing under are interfering with my GPS connection.

A vast number of us strap these little gadgets onto our wrists and use them 24/7, apparently unconcerned with the fact they're continuously monitoring us.

A distant memory are the days when we used them only to give us an rough count of our step count. Today, they can analyse our sleep quality, stress levels, oxygen saturation, our body battery.

It's a challenge 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 accurate representation of reality? Do they boost our daily wellness, or do the multitude of readings and motivational messages just contribute to our daily stresses?

A Complicated Bond

"I do get a bit obsessed with mine," an individual confesses.

While she values how her device monitors her workouts, she finds some of its other functions "overwhelming" at times - a feeling that became apparent during a major life event.

Prior to discovering she could put it into a specific mode, her smartwatch kept telling her she was not being active enough. In a new phase, the watch frequently reports her she's had a poor sleep score.

"I have a young baby, I don't need to be told my sleep was poor," she says. "I know that all too clearly."

Is it not possible to just take it off?

"It's possible, perhaps, but I have this push-pull dynamic with it," she explains. "I appreciate it for its exercise data, I sometimes question whether the additional features it can now do is perhaps overkill for me."

How Do They Work?

Every device of smartwatch has its own proprietary way of measuring your bodily functions and analysing your data, but the vast bulk use sensors on the reverse of the watch.

They typically project minute LED lights onto your wrist which can detect blood flow, recording your pulse rate. Sophisticated devices measure changes in the bioimpedance that flows through the skin to get an idea of your stress levels.

The Professional Viewpoint

A data scientist says that in general for smartwatches, it's a "delicate equilibrium" - while the continuously improving tech could realistically aid early diagnosis, "identifying issues 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 heart rhythm analysis, which regularly monitor how healthy the heart is. They can notify if someone is experiencing an irregular rhythm, where there is irregular signals 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 preliminary indication they might be more vulnerable of a stroke in the future.

But how to interpret these readings is complicated. The expert worries that as further capabilities are introduced, people may struggle to fully contextualise their data.

"I have some doubts that the ability to monitor so much data is such a beneficial thing," he says.

A health researcher specialising in wearable tech concurs. A study into the effect of wearable tech on a set of heart condition patients suggested a minority of those who were given devices to monitor their heart health experienced increased anxiety and were "far more likely to use medical services".

She observed a pattern with her patients - they noticed a concerning reading on their watch. They became worried. Their heart rate went up. They got more worried. They checked again, and their reading went up again.

"When people are presented with stats about ourselves that we don't really understand then, of course, we are going to want to know more," the psychologist says. "We look, we re-check - it becomes a feedback loop."