CardialOS: Heart & Recovery

CardialOS reads the biometrics your Apple Watch already records — heart-rate variability, resting heart rate, VO₂max, sleep, and your workouts — and turns them into a clear, honest picture of your cardiovascular recovery, training load, and fitness.

No hype, no vanity scores. Just a straight read on how your heart and body are adapting, so you can train with intent and recover on purpose.

WHAT CardialOS SHOWS YOU • Recovery — a daily read built from HRV, resting heart rate, and sleep. • Training load — acute vs. chronic load and your acute:chronic ratio, so you build fitness without digging a hole. • Strain & stress — how hard a day asked of you, and how your body is carrying it. • Cardio fitness — VO₂max trends, a heart-rate-to-VO₂ view, and a race-time predictor. • Heart-rate zones & training distribution — where your time actually goes across easy, threshold, and hard. • Workouts — per-session detail with heart-rate drift (decoupling) and efficiency. • Vitals — HRV, resting heart rate, respiratory rate, blood oxygen, wrist temperature, and sleep, with trends. • Cardiovascular age — how your fitness compares to your years.

HONEST, SUPPORTIVE GUIDANCE CardialOS's voice is plain and kind. On a hard day it tells you to hold steady and protect your sleep — not that you're crushing it. The goal is a read you can trust over months, not a dopamine hit.

YOUR DATA STAYS ON YOUR DEVICE CardialOS reads from Apple Health and does its calculations on your device. Your health data is never sent to a server — there's no account and no sign-in. (Anonymous usage and crash diagnostics help us fix bugs — never your health values. See our Privacy Policy.)

BEST WITH AN APPLE WATCH CardialOS works with the heart-rate, HRV, sleep, VO₂max, and workout data your Apple Watch writes to Apple Health. The more your Watch records, the richer your picture.

CardialOS is a personal fitness and wellness tool. It is not a medical device and does not diagnose, treat, cure, or prevent any condition. Always consult a qualified professional about your health.