Undercurrent reads your health sensors to build a daily picture of how your body is doing — and where it's heading. DAILY BODY SCORE A single 0–100 score combining stress, recovery, sleep, and cardiovascular fitness. See at a glance whether today is a push day or a rest day. STRESS & RECOVERY Your stress score is computed from heart rate variability and resting heart rate, adjusted for sleep quality. Recovery tracks how ready your body is for physical and mental demands. CARDIO AGE An estimated cardiovascular age based on VO2 max, resting heart rate, heart rate recovery, and HRV. See how your fitness compares to your actual age. SLEEP ANALYSIS Track total sleep, deep sleep, REM, and sleep efficiency. See how your sleep trends compare to recommended guidelines. CIRCADIAN RHYTHM A consistency score measuring how regular your bedtime and wake time are over the past week. PERSONALIZED INSIGHTS Pattern detection across 30 days of data surfaces correlations between your sleep, stress, exercise, and recovery — with actionable recommendations. TRENDS 7-day, 30-day, and 90-day trend charts for all metrics. Spot patterns and track progress over time. PRIVACY FIRST All data stays on your device. No accounts, no cloud sync, no tracking. Undercurrent reads from Apple Health and never sends your data anywhere. Works best with Apple Watch for continuous health sensor data. Also supports manually entered health data in Apple Health.
