Smartwatches - are they making us healthy or just hysterical?

Sunday, 24 August 2025

Kevin Norquay is a senior writer based in Wellington, covering social justice, technology and community change

EXPLAINER: Do hi-tech smartwatches help or hinder our health?

Amid promising to make us inspired to be healthier, they hassle us, waking us with sleep reports, stressing us with stress scores, interrupting our relaxation with relentless “get moving” nags.

If used wisely they are helpful, but the health anxious might do well to avoid them, doctors or psychologists agree.

Mine came with modest goals. First: tell the time (oddly difficult given the frenzy of available detail). Second: calculate distance to the green, or that invisible hazard on the 11th. Third: maybe ping when a message comes through. Enough, already.

But smartwatches are right across steps, floors, calories, heart rate, oxygen, body battery, stress, sleep, notifications, and maybe the most depressing of all - weather. You need AI, or a teenager, to make sense of it all.

I knew they were trouble when I found my self leaping off the couch mid-rugby test at 7.50pm, heading away from the TV desperate to bank 250 steps before the hour expired.

Worse, I’d be climbing into bed, see “9873” steps, and be “forced” into a few frantic laps around the house to tick past 10,000.

“What are you doing, you weirdo?” asked my snug blanket-covered wife from behind her book. She’s happily immune to step counts.

Turns out she was right (yet again), the 10,000-step goal is medical myth. Benefits start around 4000 steps, and plateau after 8000. I was just walking aimlessly in circles (yet again).

It’s all in a Lancet Public Health meta-analysis of 57 studies covering 160,000 adults which found about 7000 steps a day slashes the risk of the likes of heart disease, diabetes, dementia and depression.

But are smartwatches health helpful? Yes. Accurate? Yes(ish). Anxiety-inducing? Absolutely, for some.

Psychologists warn reliance can fuel obsessive behaviour: poor sleep scores can ruin sleep, stress alerts can raise stress, missed step goals come with guilt.

Yet the benefits are real. Wearables can flag early signs of atrial fibrillation, sleep apnoea, even Parkinson’s, studies have consistently found.

Smartwatch ECGs aren’t hospital-grade, but they can spot patterns. Consumer-grade watches - let’s say less than $1000 - are solid at counting steps, tracking distance, and measuring heart rate during exercise.

But their accuracy has limits. Smartwatch ECGs range from 65% to 99% accurate, which is potentially dangerous in an emergency.

Blood pressure readings? Patchy. Given the choice between ringing 111, or tapping your watch in disbelief … grab the phone.

University of Auckland research led by Dr Ruhi Bajaj developed a tool using smartwatch data - heart rate, calories, steps, distance - which fed into AI to detect anomalies.

“We developed a prototype application that used machine learning to help visualise long-term smartwatch data, detect heart-rate anomalies, and allow healthcare providers to communicate concerns to their clients or patients,” she said in a university newsletter.

Healthcare professionals tested it, with more than 60% rating its usability positively. Many saw potential for supporting patient engagement.

But some flagged big hurdles: interpreting raw data, accuracy limits, and the risk of overwhelming doctors with extra workload. An unnecessary second opinion, maybe?

Overall the conclusion was that smartwatches supported, but should not replace, medical care. Overseas studies echo that. Wearables can screen for heart rhythm problems and sleep disorders, but they don’t replace tests or treatment.

Blood pressure evidence is shaky. ECGs can guide, but they can’t diagnose. Your watch can nudge you to the doctor, where your doctor decides.

It could come down to the type of person you are. Knowledge can be power for those who know how to use it, but ignorance might be bliss for the anxious.

It’s a digital paradox.

For the healthy and stats-curious, smartwatches motivate and inform.

But for the health anxious, those with complex or serious health conditions, or those who can afford only cheaper devices offering dodgy readings, smartwatches can worsen worry and fatigue.

Constant monitoring can come with a mental load: health anxiety, data obsession, a creeping sense of failure. Monitoring your own body and mind might well work better than peering at your wrist.

So, yes the watches are pretty good, but not infallible: if it helps you live better, great; but if it stresses you out, bin it, or shove it in a drawer, buy an hourglass or a sundial.

Count your steps if it helps. If it doesn’t, take it off, and walk away - unrecorded steps still matter.

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