You track the numbers. Underline finds the patterns across sleep, recovery and training, so you can make sense of how you feel.
Join the waitlistFitness-focused AI for Apple HealthThat harder-feeling session came after two shorter nights. Underline puts the signals together, so you have more to go on than a workout summary.
Follow the connectionTwo shorter nights came just before that harder-feeling session.
It's a connection worth looking at. Your workout summary shows the session; the days around it give you more context.
One possible connection. Not the whole explanation.
The late night. The busy week. The session that felt unexpectedly good. Underline brings your Apple Health signals into the same conversation, with fitness-focused AI that looks beyond a single score.
More context for your training. More room to be human.
Meet the bigger picture behind your health data. A little more understanding, wherever your week takes you.
Underline is coming soon to iPhone. Until then, keep listening to you.
Underline brings together the Apple Health data you choose to share and looks for patterns across sleep, movement, workouts and recovery. Its fitness-focused AI turns those connections into clear, useful context — so a harder session or a quieter week makes a little more sense.
Not necessarily. Underline is being built for iPhone and the data available in Apple Health. An Apple Watch or another connected device can add more signals, especially sleep and heart rate. What Underline can interpret depends on the data you have and choose to share.
No. This website doesn't connect to Apple Health. In the app, you'll choose which health data to share through Apple's permission controls.
Underline is coming to iPhone first. We're refining the experience before opening access. We'll share launch plans here as soon as they're ready.
Underline is designed to help you understand fitness and wellbeing patterns. A connection between signals doesn't prove what caused it, and the app doesn't diagnose or treat medical conditions. For a health concern, speak with a qualified healthcare professional.
