Apple is introducing a new Readiness app with the Apple Watch Series 12 and Ultra 4, giving users a daily score from 0 to 10 that reflects how prepared their body is for physical activity.
The feature launches with both watches on September 18 and requires the new hardware to work.
The app generates one of four classifications based on the score:
- Recover (0-1)
- Pace Yourself (2-4)
- Ready (5-7)
- Go For It (8-10)
Those ratings draw from three sources: activity data, vitals from the existing Vitals app, and the previous night’s sleep score.
A heavy training day can push the score down during that same afternoon. Consistently poor sleep or elevated daytime heart rate metrics will drag it lower over time, while steady activity levels, high heart rate variability, and quality sleep work in the other direction.
New sensors make it possible
Apple says the Readiness app depends on the upgraded Health Sensing System built into Series 12 and Ultra 4, which uses redesigned optical and electrical sensors along with larger, more power-efficient green LEDs.
Because the feature relies on that hardware for more precise readings, it will not be available on Series 11, Ultra 3, SE 3, or any earlier model, even after a watchOS update.
The App Store listing for Readiness is already live, but it mainly lets users redownload the pre-installed app if they delete it. Anyone without a Series 12 or Ultra 4 can’t run it.
How the score is calculated
Apple’s support documentation breaks down the scoring logic in detail. On the activity side, the system factors in active calories burned, workout effort ratings, and Training Load data accumulated over recent days, not just that morning.
For vitals, the app checks whether metrics like heart rate and respiratory rate are within typical ranges or trending in a direction the Vitals app flags as off.
Heart rate variability carries particular weight: higher-than-usual HRV can push vitals into the Favorable category and lift the overall Readiness score considerably.
Sleep feeds in through the existing Sleep Score feature, which Apple introduced in earlier watchOS versions. A single bad night can reduce readiness, but the system also looks at sleep consistency over recent history rather than treating any one night in isolation.
Users can add a Readiness complication to their watch face or a Smart Stack widget for a quick glance, and the Fitness app on iPhone provides deeper details.
Both Apple Watch Series 12 and Ultra 4 are available for pre-order now, priced starting at $399 and $799 respectively, with availability beginning September 18.
