Titan saves a score for every day, then recalculates recent days as new data and settings arrive. Each cause below says what happened and what you can do. Settings is reached from the avatar on Today, then the gear on You.
01Late data from Apple Health
Every Today refresh re-reads recent Health data and recalculates recent history. Sleep, Exertion, Training Load and Sleep Debt are recalculated across the last 60 days. Stress and Battery are recalculated for the last 2 days and for any day without a saved score. A workout or night of sleep that syncs late changes its day. No action is needed.
02Recovery changed before noon
Recovery works differently. A night's score can change until noon on the day you woke up, so a watch that syncs late that morning updates it. From noon on, the score stays fixed even if more readings arrive. Each night is scored against the nights before it, so a new night never moves an earlier night's Recovery. See how the Recovery score works.
03Your Stress baselines moved
Stress and Battery compare your heart rate and HRV with 60-day baselines as of today. As those baselines shift, the last 2 days are recalculated against the new values, so they can move a little from one day to the next.
04You changed a setting
These settings recalculate history when you change them. Set one back to reverse it.
- Use RMSSD for HRV, at Settings > Recovery & Sleep, rebuilds Recovery, Stress, Sleep and Battery.
- Sleep Debt Threshold, at Settings > Recovery & Sleep, and Sleep Goal, under Daily Targets on Your Profile, rescore Sleep and Sleep Debt.
- Use Custom Max Heart Rate, Max Heart Rate and Heart Rate Zones rebuild Exertion and Training Load for 60 to 180 days, set by Number of Workouts. All four live on the Your Training screen, which opens from the Your Training card on You.
05You cleared a cache or ran a resync
The Targeted Clears and Full Resync actions at Settings > Health & Connected Apps recalculate history from current Health data and settings. The rebuild covers 60 to 180 days, set by Number of Workouts, and older days stay empty. Raise Number of Workouts first to keep more history. Clear Recovery Cache also rescores Recovery nights that were already final. See resync and history.
06An app update changed a score
Each score carries a calculation version. When an update changes the math, Titan recalculates saved values from the old version.
07Titan Age history moved
Titan rebuilds 52 weeks of Titan Age from saved daily data when a new week closes, or when data changes on a day inside the most recent completed week. A new Titan Age model recalculates every past week. Each week is smoothed against the one before, so one changed week can move later weeks. Changes in the current week do not move it.
