Health Watch | Sleep trackers: Boon or bane

For many young professionals, the first thing they check in the morning is no longer the time—it is the sleep score on their smart watches. The shift reflects a growing awareness that sleep is as important to health as diet and exercise. People now want to know how well they slept and wearables promise to answer that question by tracking everything, from deep sleep and REM sleep to resting heart rate, blood oxygen levels, heart rate variability (HRV) and recovery or “readiness” scores.

Experts say the technology has encouraged many people to take sleep seriously for the first time. The information can also motivate healthier habits, such as sticking to a bedtime, reducing late-night screen time or cutting back on caffeine. But there is another trend emerging alongside it. Instead of helping people sleep better, the data is making some worry more about sleep. Many users now obsess over increasing their deep sleep or understanding why their readiness score is dropping.

Experts caution that consumer wearables are useful for identifying broad trends, but they are not medical devices. Sleep stages are estimates based on movement, heart rate and other signals, and should not be treated as precise measurements. Researchers have even coined a term for this phenomenon: orthosomnia—the unhealthy pursuit of perfect sleep driven by wearable data. Ironically, worrying excessively about getting a good night’s sleep can itself make it harder to fall asleep. But this does not mean people should stop using sleep trackers. Experts say they can be most useful when viewed as long-term guides rather than daily report cards.