Cover Sleep trackers tell us about bodily processes that were once largely invisible, translating sleep into stages, graphs and readiness scores (Photo: Getty Images)
Sleep trackers tell us about bodily processes that were once largely invisible, translating sleep into stages, graphs and readiness scores (Photo: Getty Images)
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Sleep trackers can reveal patterns in how we rest. But does this extra data really help users get healthier with better sleep, or does it just make nighttime another source of pressure?
You wake feeling reasonably rested. Then you check your phone: your sleep score is lower than expected, your deep sleep is apparently lacking and the app suggests taking it easy. Within minutes, the ordinary morning is now tainted with the evidence of a bad night.
For some people, this information is useful. A wearable may reveal that their bedtime has been drifting later, that travel has disrupted their routine or that alcohol reliably coincides with a higher overnight heart rate. For others, the score begins to outrank experience—they may have felt fine until the app told them otherwise.
Also read: Inside Asia’s biohacking landscape: the science, trends and scientists to know
We now have access to biofeedback and sleep technology like never before, in the form of wearables like rings, watches and bands that tell us about bodily processes that were once largely invisible, translating sleep into stages, graphs and readiness scores.
But sleep is not entirely amenable to optimisation. A tracker can make an invisible pattern easier to see, but it can also turn rest into a nightly performance review. Accuracy is only part of the question; the other is whether the information these devices provide is genuinely helpful.
What sleep trackers measure—and how much to trust
A consumer tracker does not observe sleep in the same way as a clinical sleep study. The latter records polysomnography signals, including brain activity, eye movement, muscle activity, breathing, heart rate and blood oxygen; most rings, watches and bands instead measure combinations of movement, pulse patterns, heart-rate variability, temperature and oxygen levels. Software then uses an algorithm to infer whether the wearer was awake or asleep and to estimate light, deep and REM sleep. In other words, the sensors record physiological signals; the algorithm turns them into a story about the night.
Research suggests these devices are generally better at recognising broad sleep periods than reconstructing every stage precisely. A 2024 laboratory study showed that the Oura Ring Gen3, Fitbit Sense 2 and Apple Watch Series 8 were highly sensitive at detecting sleep, but their sensitivity for individual stages ranged from about 50 to 86 per cent. In the meantime, a 2026 rapid review of 29 real-world studies likewise found moderate accuracy for total sleep time and time in bed, with lower precision for measures such as sleep efficiency, waking after sleep onset and stage classification.
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Above What users and reviewers say about the Oura Ring 5, Apple Watch 11, Whoop 5.0, Samsung Galaxy Ring and Ultrahuman Ring Pro
What users and reviewers say about the Oura Ring 5, Apple Watch 11, Whoop 5.0, Samsung Galaxy Ring and Ultrahuman Ring Pro
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When data helps
The strongest case for sleep tracking is not the precision of one night’s score—it is the ability to observe patterns over weeks or months.
The World Sleep Society’s 2025 recommendations for consumer health trackers, led by Prof Michael Chee from the National University of Singapore (NUS), propose that wearables can serve as continuous sleep diaries or “sleep minders”. It’s the most basic measurement that are the most useful: when someone goes to bed, when they wake, how long they sleep and how consistent those timings are. Exact estimates of deep and REM sleep deserve more caution.
That longer view of the data can reveal patterns that manual tracking might overlook. Someone may discover that their sleep is consistently shorter during the working week, that frequent regional travel shifts their schedule for several days or that late dinners repeatedly coincide with changes in overnight heart rate. For shift workers, caregivers and people with irregular social or professional schedules, even a rough record may make recurring disruption easier to recognise.
The data can also help personalise medical knowledge. Knowing abstractly that alcohol, late meals or inconsistent bedtimes may affect sleep is different from seeing the same association appear repeatedly in one’s own record. Of course, the data does not prove cause and effect: heart rate and sleep can be influenced by numerous variables, while the app’s analysis remains algorithmic. But it may provide a reasonable starting point for changing one habit and observing what happens.
Read more: Can AI help us live better for longer?
When tracking makes sleep harder
The same feedback can become counterproductive when sleep shifts from something to experience into something to perfect. In 2017 researchers introduced the term orthosomnia in a case series involving three patients who had become preoccupied with improving their sleep tracker data. Some extended the amount of time they spent in bed in pursuit of better numbers, despite this conflicting with established behavioural approaches to insomnia.
While orthosomnia remains a proposed concept rather than a formally established standalone diagnosis, the concept is nevertheless plausible: a low score increases worry about fatigue or long-term health, and that worry produces greater vigilance around the next night. The user spends more time monitoring, planning and trying to force sleep. Another imperfect result then appears to confirm that something is wrong, creating a vicious cycle.
A 2018 experiment involving 63 people with insomnia helps explain why feedback can carry so much authority. Participants received false actigraphy results indicating that they had slept either well or poorly. Those given negative feedback subsequently reported lower alertness and greater sleepiness and fatigue than those given positive feedback, even though the assessment was fake. So while the finding does not show that ordinary tracker use routinely causes insomnia, it does suggest that being told one slept badly can shape how the following day is experienced.
Above For some users, an imperfect sleep score can become another source of anxiety (Photo: Unsplash)
For some users, an imperfect sleep score can become another source of anxiety (Photo: Unsplash)
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App design may reinforce this effect. A message that says deep sleep was “below optimal” can sound more authoritative than the underlying estimate deserves. Daily scores also compress several imperfect measurements into a number that appears easy to understand but cannot be compared directly with a score from another brand. Different manufacturers use different sensors, definitions and proprietary weightings.
So the problem is twofold: a tracker may misread the night, or at least provide different readings across different brands; and then on the human side, users may begin to give that reading more authority than their own experience.
How to use a tracker without letting it run your life
The bottom line is that sleep data is not inherently helpful or harmful. Their effect depends on what is measured, how it is presented and how the user interprets it.
In a randomised Australian trial known as the Novel Insomnia Treatment Experiment, researchers assigned 113 adults with significant insomnia symptoms to receive either sleep education or five weeks of wearable monitoring accompanied by feedback and guidance on interpreting the results. The guided group reported moderately greater reductions in insomnia severity and sleep disturbance, although there were no meaningful advantages in anxiety, depression, sleep-related impairment or several measures of discrepancy between perceived and recorded sleep. The researchers stressed that the effects were modest and that wearable feedback was not sufficient as a treatment on its own.
For everyday use, a tracker is better approached as a diary than a judge. Consider how you feel before opening the app. Look at several weeks rather than reacting to one night. Give more weight to sleep timing, duration and regularity than to exact stage estimates. Compare patterns within the same device rather than treating scores from different brands as equivalent. When testing a habit, change one factor at a time.
Above Both the American Academy of Sleep Medicine and the National Sleep Foundation caution against treating consumer sleep technologies as substitutes for appropriate clinical evaluation (Photo: Unsplash)
Both the American Academy of Sleep Medicine and the National Sleep Foundation caution against treating consumer sleep technologies as substitutes for appropriate clinical evaluation (Photo: Unsplash)
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Stopping tracking is also a reasonable option, especially if checking the app increases anxiety, encourages compulsive behaviour or makes sleep feel like another health target to optimise, the information is no longer serving its intended purpose.
Persistent insomnia, pronounced daytime sleepiness, loud snoring or repeated pauses in breathing are possible health symptoms—not merely poor sleep scores to optimise. Both the American Academy of Sleep Medicine and the National Sleep Foundation caution against treating consumer sleep technologies as substitutes for appropriate clinical evaluation. They may contribute information to a conversation with a professional, but they cannot reliably diagnose or rule out a sleep disorder.
Sleep trackers can help when they make patterns visible and support realistic changes. They can make sleep harder when a proprietary score adds vigilance and judgement to a process that depends partly on letting go.
The best tracker may be the one that tells you enough to change something useful, and then allows you to turn it off.
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Kristine Fonacier is a widely published journalist and author, covering lifestyle, business, politics and travel. She was the editor in chief at the Philippine editions of Esquire and Entrepreneur, and the founding editor of Grid magazine. At Tatler, she was previously the regional editor for T-Labs, Power & Purpose and Asia’s Most Influential.
