Data guide
How every Vita metric is calculated: inputs, weights, bands, limitations, and the research each rests on. Written for people who want to know why a number should be believed.
How recovery is calculated
Recovery is a 0–100 reference score that compares today's HRV, resting heart rate, sleep, respiratory rate and wrist temperature against your own trailing 28-day baseline, then weights them — it measures you against your usual, not against other people.
See the method →How the sleep score is calculated
The sleep score is a 0–100 reference score combining duration (50%), deep-sleep share (25%), REM share (15%) and sleep efficiency (10%), each read against your own trailing 28-day baseline — because Apple Health gives you sleep stages but no score.
See the method →How activity load is calculated
Activity load is a 0–100 reference score for where today's expenditure sits within your own past 30 days — 70 means "heavier than about 70% of your usual days", not any absolute training standard.
See the method →How Body Age is calculated
Body Age starts from your actual age and adds or subtracts years according to how each of seven signals compares with an age-referenced value — every term is individually capped, and the result is their sum. It is a reference index, not a measurement of biological age.
See the method →Why we compare you with yourself
Vita's recovery, load and sleep scores are not compared with population norms but with your own trailing 28-day baseline, computed from the median and median absolute deviation (MAD), and requiring at least 7 days of data.
See the method →Every metric on this page is a reference index for observing your own trends. It is not medical advice and cannot replace a professional diagnosis. If you have health concerns, consult a qualified clinician.
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