Glossary
Wearable Metrics
Updated February 28, 2026
Wearable metrics capture activity and recovery data that inform daily plans. See Personalized Metrics for details.
Metric glossary
Each wearable metric serves a specific purpose in tracking your health patterns, though reliability varies significantly across devices and contexts. Understanding these limitations helps you interpret data more effectively and avoid overreacting to single measurements.
| Metric | What it tracks | Typical reliability |
|---|---|---|
| Steps and movement | NEAT and low-intensity output | medium |
| Heart rate and zones | cardio load and intensity | medium to high, high for intervals |
| Sleep duration and efficiency | sleep quantity and continuity | medium, depends on device |
| HRV | readiness and nervous-system trends | medium, strongest as trend |
Confidence bands and interpretation
Smart interpretation requires distinguishing between meaningful signals and random noise in your wearable data. These guidelines help you identify when changes reflect real physiological shifts versus temporary fluctuations.
| Pattern | Band rule |
|---|---|
| Single-night drops | treat as noise unless repeated 2 to 3 nights |
| Sudden spikes | verify manually for context (illness, heat, stress) |
| Stable 2-week pattern | use for plan-level decisions |
| Cross-device mismatch | prefer manual baseline until one device repeats trend |
Calibration workflow
Establishing reliable baselines takes patience and systematic observation rather than trusting initial readings. This structured approach helps you build confidence in your device's accuracy for your specific physiology and lifestyle.
| Step | Action |
|---|---|
| 1 | keep one device and one metric set for baseline period |
| 2 | run 3 to 5 days of manual checks for sleep and steps |
| 3 | compare trend direction before macro or calorie changes |
| 4 | recalibrate if two metrics conflict for 7 to 10 days |