Your biological age trends, on iPhone and Apple Watch
My Bio Age uses available Apple Health data on your iPhone to calculate a weekly biological age estimate and daily wellness scores. The companion watch app shows your Index, Recovery, Training Load, Stress Resilience, and Circadian Alignment with readable status indicators. The app is completely free, with no in-app purchases, subscription or account.
Your Index and daily scores on your wrist
Open the watch app while your iPhone is reachable to request updated scores. The watch keeps previously received values available offline, so check that your latest phone data has synced before interpreting a change.
- MyBioAge Index with trend direction and status color.
- Recovery Capacity with Ready/Moderate/Limited indicators.
- Training Load as a ratio with a status label.
- Stress Resilience Score (0-100) with color-coded zones.
- Circadian Alignment Score (0-100) with instant status feedback.
Color-coded feedback at a glance
Color and text labels help you scan the scores in the watch app. Open My Bio Age on iPhone for detailed signals, trend charts, and guided AI Coach explanations. A status color is wellness context, not a medical assessment.
- Read the score alongside its status and available data.
- Use iPhone trend charts to compare changes over time.
- Consider how you feel as well as what the app shows.
- Daily scores and the weekly Index use different time windows.
Built for Apple Watch athletes and everyday movers
Use your weekly Index and daily scores to reflect on routines over time. The consumer app is for wellness and fitness; it does not diagnose conditions, prescribe treatment, or establish whether a training session is safe.
What you will see on Apple Watch
- MyBioAge Index with color-coded status and trend direction.
- Stress Resilience and Circadian Alignment scores (0-100).
- Recovery Capacity with Ready/Moderate/Limited indicators.
- Training Load as a ratio with a status label.
How the Apple Watch biological age app works
- Install My Bio Age on iPhone and Apple Watch, then connect Apple Health.
- Allow VO2 max, heart rate variability, sleep, and activity permissions.
- Wear Apple Watch through workouts and overnight for the richest dataset.
- Review your weekly MyBioAge Index™ and daily scores on iPhone.
- Enable the Monday 10 AM reminder to review your in-app Weekly Digest.
Apple Watch sensors that shape your biological age
My Bio Age reads supported categories from Apple Health when you open and refresh the app. These are examples of the inputs you can explore; no single reading establishes your health status or true biological age.
- VO₂max: Review available cardio-fitness estimates and their longer-term trend.
- HRV: Compare your available readings over time, with attention to how and when they were measured.
- Resting heart rate: Put recent changes in the context of your own history.
- Sleep: Review duration and regularity alongside your other health signals.
Missing a reading?
Start by checking whether the reading exists in Apple Health. Our Apple Watch VO₂max troubleshooting guide explains why cardio-fitness samples may be missing.
Build a useful review routine
Review weekly changes
Use the Weekly Digest to see changes in the app’s estimate without assuming that one habit caused them.
Test a new training block
Compare available HRV, cardio-fitness, and Training Load trends across your training routine.
Dial in recovery rituals
Review sleep consistency and recovery patterns alongside your daily routine and how you feel.
Ready to explore your Apple Watch health trends?
Download My Bio Age free on the App Store, choose your Health permissions and explore your available trends. Your scores and optional AI Coach run entirely on iPhone, keeping your health data private. No subscription. No in-app purchases.
Apple Watch biological age FAQs
How does My Bio Age calculate biological age from Apple Watch data?
My Bio Age reads permitted Apple Health data and calculates the MyBioAge Index™ on iPhone using complete Monday-to-Sunday weeks. It combines 12 health inputs, or 14 with blood pressure, into a wellness estimate. The watch displays scores received from the phone; it does not calculate biological age itself.
Do I need to wear my Apple Watch all day for biological age tracking?
Consistent wear during everyday activity and sleep can provide more data to review. Availability varies by watch model, settings, permissions, and reading type. Missing readings can limit the app’s scores; more data does not make the estimate a clinical test.