The Promise and Perils of Sleep Tech
What Trackers Actually Measure
Movement vs. Sleep Stages
Most consumer devices estimate sleep stages through movement and heart rate variability, not brain waves like clinical polysomnography.
Accuracy Limitations
Studies show wearables overestimate sleep by 30-40 minutes and struggle to distinguish wakefulness from REM sleep.
The Placebo Effect
Simply tracking sleep often improves habits temporarily, regardless of data accuracy – known as the “observer effect.”
Best Use Cases
Trackers excel at identifying patterns over time rather than analyzing single nights’ sleep quality.
Smart Tracking Strategies
Choosing Your Device
Wearable vs. Non-Wearable
Under-mattress sensors better detect micro-movements while wrist devices track heart rate more continuously.
Clinical-Grade Options
FDA-cleared devices like Dreem headbands provide EEG data but cost 10x more than consumer wearables.
Minimalist Alternatives
Basic sleep diary tracking for 2 weeks often reveals patterns as effectively as expensive tech for many users.
Healthy Data Habits
The 80/20 Rule
Focus on trends across weeks rather than nightly scores to avoid “sleep performance anxiety.”
Correlation Hunting
Note connections between lifestyle factors (caffeine timing, exercise) and sleep metrics rather than fixating on scores.
Tech Breaks
Take 1-2 nights off tracking weekly to maintain healthy relationship with sleep data.