Sources & Methodology
Vita (iOS app) & 100old.app (web app)
01Important notice
All health information, scores, estimates and AI guidance in Vita are for general health and fitness reference only and do not constitute medical advice, diagnosis or treatment. Consult a qualified physician or healthcare professional before making any health, medication or exercise decisions, and whenever you have a health concern. In an emergency, seek medical care immediately.
Vita does not connect to, pair with, or control any medical device or hardware. It only reads data you already have: from Apple Health (HealthKit) and from WHOOP via WHOOP's cloud (OAuth) API. WHOOP, Apple Watch and similar products are consumer health/fitness devices, not regulatory-cleared medical devices; Vita does not provide clinical diagnostic interpretation of their measurements.
02Method & evidence base
Vita's metric interpretations and guidance draw on published exercise-physiology, sleep- medicine and nutrition-science literature, together with the “Medicine 3.0” preventive-health framework described in Outlive. Sources are listed by topic below. Individual variation is large; these sources provide general reference ranges and direction, not a medical judgment about you personally.
Overall framework
- Attia P, Gifford B. Outlive: The Science and Art of Longevity. Harmony, 2023.
03Body Age / cardiorespiratory fitness (VO₂max)
Body Age is an estimate based on published research, combining VO₂max, resting heart rate, heart rate variability, daily steps, sleep and recovery to convey long-term trend — it is not a clinical age assessment. The link between cardiorespiratory fitness (VO₂max) and long-term outcomes draws on:
- Mandsager K, et al. Association of Cardiorespiratory Fitness With Long-term Mortality. JAMA Network Open. 2018;1(6):e183605. doi:10.1001/jamanetworkopen.2018.3605
- American College of Sports Medicine. ACSM's Guidelines for Exercise Testing and Prescription (VO₂max age/sex normative reference), 11th ed., 2021.
04Sleep
Reference ranges for sleep duration and structure draw on:
- Hirshkowitz M, et al. National Sleep Foundation's sleep time duration recommendations. Sleep Health. 2015;1(1):40–43. doi:10.1016/j.sleh.2014.12.010
05Heart rate variability & recovery
HRV metric meaning and normative reference draw on:
- Shaffer F, Ginsberg JP. An Overview of Heart Rate Variability Metrics and Norms. Frontiers in Public Health. 2017;5:258. doi:10.3389/fpubh.2017.00258
Recovery and Strain scores are computed by WHOOP; Vita only displays them. Their algorithmic definitions are governed by WHOOP's own documentation.
06Nutrition & protein
Protein intake and per-meal targets draw on:
- Jäger R, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. doi:10.1186/s12970-017-0177-8
Calories and macros from photo analysis are AI estimates and vary with ingredients, portion and preparation; they are for logging and trend reference only.
07Lab reference ranges
Reference ranges in health reports (e.g. glucose, lipids, HbA1c) are provided by the issuing laboratoryand follow standard clinical ranges. Ranges differ across labs and assay methods — defer to your original report and the issuing lab. Vita only structures and generally describes the values you upload; it does not replace a physician's interpretation.
08AI-generated content
Vita's insights, Q&A and “buddy” chat are generated by third-party large language models (see Privacy Policy §6). The content is grounded in the evidence base above and your data, is general health information, may be inaccurate or not applicable to your personal situation, and does not constitute medical advice. Defer to your physician for important health decisions.