Do sleep trackers actually work?
Short Answer
Sleep trackers can estimate sleep timing and trends, but they’re not very accurate for sleep stages. They’re useful for noticing patterns, yet they can misclassify wakefulness and shouldn’t replace clinical evaluation.
Why This Matters
This matters because data can help behavior change—seeing bedtime drift or short nights leads to better planning. But false precision results in anxiety (“I only got 12% deep sleep”), which can worsen insomnia. Using trackers for big patterns rather than nightly scores leads to better outcomes.
Where This Changes
If you have significant daytime sleepiness, loud snoring, or witnessed apneas, a sleep study is far more informative than a wearable. If tracking makes you obsess or sleep worse, it’s reasonable to take a break and focus on how you feel and function.