Sleep Metrics That Matter
Clinically Valid Measurements
Heart Rate Variability
HRV scores correlate 0.89 with deep sleep quality.
Resting Heart Rate
Nighttime RHR below daytime average indicates recovery.
Questionable Metrics
Sleep Stage Accuracy
Consumer devices misclassify stages 30-50% of the time.
Absolute Sleep Duration
Quality matters more than rigid 8-hour targets.
Optimizing Tracker Usage
Data Interpretation Framework
Trend Analysis
Weekly patterns reveal more than nightly fluctuations.
Personal Baselines
Compare to your norms, not population averages.
Actionable Correlation Strategies
Lifestyle Experimentation
Test one variable at a time (caffeine, exercise timing).
Morning Alertness Journaling
Combine subjective and objective data for full picture.