The truth in your wearable tech
- Samantha Herbst
From step counts to sleep scores, wearable tech is changing how we think about our health. Can we trust the data when it begins to override our own instincts?
Having only become commercially available less than 20 years ago, wearable technology has quickly become part of modern life. Smartwatches, fitness trackers and biometric rings now help millions of people count steps, track sleep and monitor heart rate and VO2max.
These devices promise unprecedented insight into our bodies, translating movement, heart rate and recovery into measurable health data. However, as we become increasingly reliant on them, an important question emerges – are wearables helping us understand our bodies better or teaching us to trust data over instinct?
Faith in technology
For Dr Dale Esliger, Professor of Digital Health Technologies at Loughborough University – a key academic collaborator in the development of research initiatives at the – trust is central to the success of wearable technology.
He notes that wearables help people determine whether they are meeting their physical activity goals, which is why consumers want to know that the metrics are valid and that they can trust the tool that they are wearing.
“If they lose faith in that validity, that fitness tracker ends up in the sock drawer and so do our interventions as healthcare professionals,” says Esliger.
Validity in metrics
Esliger believes that wearable devices should be subjected to the same scrutiny as any instrument used to inform health decisions.
"Every time we purchase a new piece of technology, we must kick the tyres," he says.
"You wouldn't buy a high-powered medical MRI scanner for your new building and not want to know the validity of that device. Yet we grab wearables off the shelf, research-grade or consumer ones, and we put them on, expecting the [manufacturer] to follow through with what they promised.”
Esliger acknowledges, however, that while scientific rigour remains essential, perfect accuracy is not always the point when it comes to encouraging people to move more.
A landmark study
Professor Jon Patricios, Director of µÚÒ»³Ô¹ÏÍø Sport and Health (WiSH) last year published a study showing that as little as 60 minutes of weekly exercise before a cancer diagnosis reduced the risk of disease progression by 27% and death by 47%.
Although wearables were used in the research, Patricios emphasises that people do not need a smartwatch to reap the benefits of regular moderate exercise.
"The low levels of exercise required for at least some benefits are easily achievable by anyone. We should all be encouraged to use exercise as medicine!"
Behaviour before precision
Professor Georgia Torres, Head of the Department of Exercise Science and Sports Medicine at µÚÒ»³Ô¹ÏÍø, who was also part of Patricios’ research group, agrees. She is less concerned with whether wearable devices produce perfectly accurate numbers than whether they help people become more active.
"It's not about the actual figure, it's about understanding the trend. Regardless of the value, if the intervention inspired by the wearable device helps to increase physical activity, that's what matters," says Torres.
Increasingly, wearable technologies are used by µÚÒ»³Ô¹ÏÍø researchers to understand physical activity patterns beyond controlled research settings.
"What happens outside the three hours that we are with a patient is going to influence the outcomes of what we are doing much more than what we do in the gym or the lab," says Torres.
According to Torres, the real power of wearable devices lies in the insight that they provide into the factors that influence movement data outside the research setting.
One factor could, for example, be a largely sedentary lifestyle that counteracts the benefits of vigorous or moderate exercise. Alternatively, a more active lifestyle motivated by a daily step or movement goal, prompted by a wearable device, reveals more about movement trends than what researchers would identify within their more defined research parameters.
When data changes behaviour
Wearable technology does not just measure behaviour – it can shape it. It may encourage healthier habits but it can also negatively influence behaviour when users begin trusting data more than their own internal cues, bypassing interoception.
"My problem with sleep devices, for instance, is that they can become a behavioural barrier. You can wake up feeling refreshed and rejuvenated but if your smartwatch says you haven't slept well, your brain will convince you that you haven't slept well," says Torres.
Patricios agrees: "There is no one sleep pattern that is best for everyone. Some thrive more on deep sleep, others on REM," he says, adding that everyone's sleep requirements vary.
Wearables can therefore become both motivators and psychological barriers, particularly when users begin trusting algorithms more than their own lived experience.
Simpler may be smarter
For Torres, consumer wearables should be viewed as tools rather than absolute truths. The challenge is not making wearables more sophisticated but making them more accessible.
Because wearable devices remain beyond the financial reach of many South Africans, she believes that smartphones may become the most effective behaviour-change tool.
"It's good for research to understand things, but you have to use simpler technology to incentivise those who are economically disadvantaged and I think that smartphones are going to be one of our access points."
Ultimately, the greatest value of wearable devices may not lie in producing increasingly sophisticated health metrics but in helping more people make healthier choices.
Moreover, in a country where physical inactivity remains a major public health concern, simplicity may be more powerful than sophistication.
"You don't want to get too technical when it comes to encouraging inactive people to move," says Torres. "Wearable technology should be a tool that nudges users in the right direction."
A holistic view of healthcare
Within µÚÒ»³Ô¹ÏÍø University’s Department of Exercise Science and Sports Medicine, researchers, including Professor Georgia Torres, Professor Philippe Gradidge and Dr Merling Phaswana have been using wearable technologies and accelerometry data to study physical activity patterns in workplaces, communities and during health interventions.
This type of work will be expanded through the new µÚÒ»³Ô¹ÏÍø Brian and Dorothy Zylstra Sports Complex, where wearable technology and its AI-enabled platforms will allow an interdisciplinary medical team – including sports scientists, clinicians, biokineticists and physiotherapists – to look at programmes more holistically.
“It’ll give us a more holistic look at the data, as opposed to one unit’s point of view, which is a research gap that needs to be addressed,” says Torres, who is also the Chief Operating Officer of the .
- Samantha Herbst is a freelance writer.
- This article first appeared in CURIOS.TY, a research magazine produced by  and the .
- Read more in the 21st issue, themed #Trust — the invisible glue binding society, science and technology.