A generic "resting heart rate is 60-100" range is useless for serious analysis. Your heart rate at 9am sedentary is different from your heart rate at 3pm post-coffee, which is different again from after a workout.
Verge builds a contextual baseline: a separate expected value for each combination of:
- Time of day — morning, midday, afternoon, evening, night
- Activity state — sedentary, light, walking, working out, post-workout
- Recent context — post-meal, post-caffeine, post-nicotine, or none
When you trade in the afternoon after a coffee, Verge compares your live heart rate against your typical afternoon-post-coffee baseline, not against a population average. The deviation it reports is meaningful.
The baseline takes a few weeks to settle into all the contexts you actually live in. During that calibration period, Verge shows the confidence level explicitly — so you know whether the deviation it's reporting is reliable yet.