I built Sarvita because I wanted to answer one question: am I getting biologically younger?

Apple Health already collects VO2 Max estimates, HRV, body composition, workout logs, and sleep data. But it doesn't synthesize this into anything actionable. Sarvita pulls this data and calculates three component ages — VO2 Max Age, HRV Age, and Body Composition Age — using age-percentile reference tables from population studies.

The AI coach then delivers weekly training plans based on the 4 exercise modalities with the strongest mortality-reduction evidence: Zone 2 cardio (mitochondrial biogenesis), strength training (sarcopenia prevention), VO2 Max intervals (the single strongest predictor of all-cause mortality per JAMA 2018), and stability work (fall prevention).

Technical notes: - iOS native, Swift/SwiftUI - Health data stays on-device. The AI coaching queries are processed via API and immediately discarded — no persistence of health data on my servers - Sync through the user's own iCloud account - Meal tracking uses vision AI — photo → macro estimation in seconds - Biological age calculation weights VO2 Max most heavily (~40%), reflecting the research on mortality prediction

The longevity science framework comes primarily from Attia's synthesis in Outlive, but the underlying research (Mandsager 2018, PURE study, Cochrane fall-prevention reviews) is independently solid.

Free to try: https://apps.apple.com/us/app/longevity-tracker-dont-die/id6...

I'm a solo dev. Feedback on the approach, the science, or the product is very welcome.