Most common reason: Data is too recent

True Age uses a 28-day lookback window from last Sunday, not the current week.

This is the most frequent cause of missing metrics. If you've only entered data this week, it won't appear in your True Age calculation yet.

Why this happens:

True Age calculates from a trailing 28-day period ending last Sunday
Data from the current week (Monday onwards) isn't included in the current calculation
You need at least 4 weeks of historical data before last Sunday

Example timeline:

Today is Tuesday, January 13
Last Sunday was January 11
True Age looks back 28 days: December 14 - January 11
Any data you entered January 12 or later won't show yet

Fix: You'll need to wait and continue recording data consistently. Your metric will appear once you have enough data in the 28-day lookback window. This takes time, but ensures your True Age reflects established patterns rather than just a few days of data.

Other reasons metrics might be missing

Not enough data for the calculation

True Age requires minimum data thresholds for each biomarker. If you don't meet them, the metric won't appear.

Minimum requirements per week:

RHR: At least 4 measurements
HRV: At least 4 measurements
VO2max: At least 1 measurement
LBMI: At least 1 measurement (plus height)

Check your data completeness:

Open reThrive Home screen
Look at the This Week card
Each biomarker shows dots for recorded days
If fewer than 4 dots for RHR or HRV, you need more data

Fix: Wear your device more consistently, especially at night for RHR and HRV.

Learn more at What does Confidence score mean.

Gap in your data history

If you took a break from wearing your device, you might not have enough recent data in the 28-day window.

Why your metric might be missing:

You took a break from wearing your device
Your device battery died for several days
You changed devices and lost recent history
You only started tracking recently

Fix: Start wearing your device consistently. True Age will appear as you gather new data over the coming weeks.

Missing Apple Health sync

If data isn't syncing from Apple Health to reThrive, metrics won't calculate.

Fix: See Apple Health sync issues for troubleshooting steps.

Missing body composition data

LBMI requires at least one body composition measurement (weight and body fat percentage or lean mass).

If LBMI is missing:

Check if you've recorded weight and body composition in Apple Health
Record a new measurement from a smart scale or manual entry
Make sure height is recorded in Apple Health

See My LBMI is missing for detailed steps.

Missing VO2max measurements

VO2max requires cardio fitness data from outdoor activities tracked with GPS.

If VO2max is missing:

Do outdoor walks, runs, or hikes with your Apple Watch
Make sure GPS tracking is enabled
Push your heart rate up during the activity
Wait for Apple Health to calculate and record VO2max

Note: Indoor workouts typically don't generate VO2max estimates.

Troubleshooting specific metrics

True Age isn't showing

True Age requires all four biomarkers to have sufficient data in the 28-day lookback window.

Check each biomarker:

Do you have 4+ weekly measurements of RHR in the past 28 days (before last Sunday)?
Do you have 4+ weekly measurements of HRV in the past 28 days?
Do you have at least 1 VO2max measurement in the past 28 days?
Do you have at least 1 LBMI measurement in the past 28 days?

If any biomarker is missing, True Age won't calculate.

See What is True Age to understand the calculation.