Why your watch data and your blood panel belong in the same view, what each one can and cannot tell you, and how Delta puts both in one private dashboard.
Most people who care about their health have two kinds of data that never meet. A watch or ring records heart rate, sleep, and activity every day. A blood test, once or twice a year, records what is happening inside. They usually live in different apps.
Wearables are frequent. They show how you slept last night, how hard you trained this week, and how your resting heart rate is trending. They are good at short-term change. They cannot see your blood sugar control, inflammation, or kidney function.
Blood tests are deep but rare. A routine panel shows markers such as fasting glucose, C-reactive protein, albumin, and creatinine. From nine of them, plus your age, you can compute a blood-based biological age. It is good at long-term position. It cannot tell you how you slept.
Neither replaces the other. Together, they give you the day-to-day and the long view.
Delta is one app for both. It reads from Apple Health on iPhone or Health Connect on Android, and connects to Withings for body composition. It also logs training, nutrition, and mood. Then you add your blood reports as PDFs or photos.
Your blood results produce an Adaptive Age, computed on your device with the published PhenoAge formula. Your wearable data sits in the same dashboard, so you can see what your habits looked like in the months between two panels.
If you do not have a blood test yet, Delta can show Vitals Age, an estimate built from wearable signals only. It is clearly labelled as an estimate with a wider range, and it never changes the blood-based number. You can read more in Vitals Age: what your watch can and cannot tell you.
Blending a watch estimate into a blood score would make the score harder to trust. Delta keeps them apart on purpose. Adaptive Age comes only from blood markers. Wearable data adds context around it.
A dashboard that joins your heart rate, sleep, weight, and blood work is a detailed picture of you. Delta stores that picture on your phone. There is no account and no sign-in. See our privacy policy for the few things our servers do hold, and how to erase them.
Delta is free on iPhone and Android. Get Delta.
