Worn Out by Wearables: Health Isn’t a Number
The Seduction of Measurement
Wearable health tech has become the new normal. From smartwatches to biometric rings, we are tracking sleep, steps, heart rate, and breathing like never before. These devices promise optimization, insight, and prevention. But what they usually deliver is distraction, anxiety, or even harm. We are told we can fine-tune our lives to perfection if only we measure everything. But does measuring actually make us healthier, or does it simply turn us from people into patients?
Mistaking Health for Health Measures
Health is not the same as health metrics. It is built on eating well, exercising regularly, sleeping adequately, spending time outdoors, nurturing relationships, and cultivating reflection or a spiritual practice. None of these require a dashboard, and none can be reduced to the readout on your watch.
Step Counters Work, but Only a Little
Let’s start with what might work. Step counters and activity trackers can help people move more. In a review of 164,000 participants, they added ~1,800 steps per day, 40 minutes of walking, and wearers lost about 2.2 pounds (Ferguson 2022). Those effects are real, but some might simply be a Hawthorne effect: people move more when they know they’re being observed. Other studies suggest that those gains often shrink over the subsequent year (Chaudhry, 2020).
In my opinion, step counters can help get people started, but they don’t solve the harder problem of sustained lifestyle change. Once you’re up and active, believing that hitting 10,000 steps makes you “fit” or checks the box for your day’s physical activity is misleading. It reduces health to compliance with a device, not the pursuit of vitality.
Oura’s Validation Problem
Oura markets its ring as a sophisticated health device that measures your heart rate variability (HRV) and claims that it provides “insights into stress levels, as well as overall health and well-being.” Oura also suggests that day-to-day changes “can help you know how to approach your day.” But the published validation data do not support these claims (Cao, 2022) or the promise that you can wake up, check your HRV, and decide whether to train harder or rest. The tool isn’t sufficiently sensitive or accurate to guide day-to-day lifestyle decisions. Furthermore, in validation studies, ECG output was simplified to match Oura’s 5-minute snapshots, making the comparison easier but less fair. In my research lab, under carefully controlled conditions with validated algorithms and continuous ECG monitoring, it takes 50–80 people in a study to identify a true difference beyond biological variability and measurement error. Expecting a consumer ring to make those judgments for a single person, day to day, is unrealistic.
Technical Details – OK to skip: HRV is typically reported in milliseconds (ms) using RMSSD (root mean square of successive differences between beats). Against a gold-standard 3-lead ECG, Oura’s limits of agreement for RMSSD are on the order of ±15 ms for overnight averages and ±29 ms for 5-minute windows, with a systematic bias toward lower values. That means the ±5–10 ms wiggles you see from day to day fall entirely within measurement scatter and normal biological variability. At the individual level, these devices cannot reliably distinguish small changes from noise, particularly in short time windows. The limitation is not just hardware, but the combination of photoplethysmography, motion artifact, and physiologic variability, all of which degrade signal resolution in real-world conditions.
The Big Problem With the Data
Most wearable metrics aren’t actionable for healthy people, but they can easily convince you something is “off” - and that is a real harm.
HRV fluctuates with hydration, caffeine, alcohol, circadian rhythms, and more, yet consumer wearables can’t resolve meaningful changes. VO₂ max estimates are notoriously inaccurate, and day-to-day swings often reflect software more than physiology. Oxygen saturation is irrelevant outside of lung disease or high altitude, and even in illness it drops late, so it’s rarely useful for early detection in otherwise healthy people.
False Precision, Real Consequences
I once took care of a patient who had felt nauseated and short of breath. But his Apple Watch showed his oxygen saturation was normal, his pulse rate was normal, and he did not have atrial fibrillation (AF), so he figured he was fine … except he was having a heart attack and only came in 12 hours later, after he passed out. The damage was done and he was lucky to be alive, because he did not understand the limitations of what the Apple Watch could and could not diagnose. A false sense of safety delayed vital care.
This is not rare. Abnormal rhythm alerts lead to cascades of calls, testing, and costs. A Mayo study of over 200 patients found that over 90% of alerts were not actionable, yet many underwent unnecessary testing, such as medical grade heart rhythm monitors, echocardiograms, and office visits (Kaplan 2023). These calls are common and an added tax on an already burdened healthcare system. Recall that test accuracy depends on pre-test likelihood, so in healthy people under 55-60 years old, the likelihood that an alert for AF actually is AF is low. And these devices may worsen health inequities, since sensors are less accurate in people with darker skin and are less accessible to those with lower incomes, as is access to healthcare follow-up.
The Anxiety Machine
For others, the problem is the opposite: hypervigilance. One woman with AF performed over 900 ECGs in a year, most of which were normal. Each inconclusive result triggered panic, including 12 urgent clinic visits, and ultimately a diagnosis of illness anxiety disorder (Rosman, 2020). In a recent study, AF patients with wearables reported more anxiety, more treatment concerns, and higher healthcare use; about 20% felt anxious after alerts (Rosman, 2023). Rather than reassurance, devices can create dependency, obsession, and clinical anxiety.
Wearables blur the line between being a healthy individual and becoming a perpetual patient. They amplify normal physiologic variability into “alerts.” Most rhythm notifications occur in healthy people without symptoms, triggering cascades of testing and appointments, with no improvement in outcomes.
This paradox of false reassurance in emergencies, but hypervigilance in everyday life is dangerous both for patients and healthcare systems.
Narcissism as a Feature, Not a Bug
Why are these devices so seductive? Because they feed our favorite topic: ourselves. In a culture already glued to phones, wearables give us yet another reason to look down at our wrists. They encourage constant self-surveillance. Just as we Google ourselves and check “likes” on our social media posts, we now check our watches and rings to see if we feel good!
This isn’t harmless curiosity. It draws us deeper into self-absorption, away from connection with others and with the world around us. Wearables monetize narcissism, making us believe that scrutinizing our pulse or sleep score is the same as caring for our health. It’s not.
The Inevitable Advice
Here’s the irony: whether your watch says your sleep score is 95 or 55, the advice is the same. Sleep more. Move regularly. Eat a balanced diet. Manage stress. Spend time with loved ones. We don’t need a device to tell us these truths.
Conclusion: The Illusion of Insight
Wearables promise empowerment, but often deliver obsession. They trigger anxiety, feed narcissism, and provide false reassurance, while driving waste and inequity in healthcare. Health is not a metric to be chased; it is to be lived. The best thing you can do is put down the device and live well. I just turned off my step-counter!
References:
1. Ferguson T, et al. Effectiveness of activity trackers with and without incentives to increase physical activity: systematic review and meta-analysis. Lancet Digital Health, 2022.
2. Chaudhry UAR, et al. The effects of step-count monitoring interventions on physical activity: systematic review and meta-analysis of community-based randomised controlled trials in adults. International Journal of Behavioral Nutrition and Physical Activity, 2020.
3. Cao R, et al. Accuracy assessment of Oura ring nocturnal heart rate and heart rate variability in comparison with electrocardiography in time and frequency domains: Comprehensive analysis. J Med Internet Res, 2022
4. Kaplan DM, et al. Wear with care: A call for empirical investigations of adverse outcomes of consumer health wearables. Mayo Clin Proc Digital Health, 2023.
5. Rosman L, et al. When smartwatches contribute to health anxiety in patients with atrial fibrillation. Cardiovasc Digit Health J, 2020.
6. Rosman L, et al. Wearable devices, health care use, and psychological well-being in patients with atrial fibrillation. J Am Heart Assoc, 2023.
You make some good points, but I am going to continue using my Apple Watch to keep track of my exercise and workouts. It may not be hugely beneficial but if I like using it I don’t see the harm. I rarely use the EKG function.