Apple Watch is gaining an all-new health-related app called Readiness. Here’s what you need to know about Apple’s new fitness-focused Readiness app.

Apple’s new Readiness app is part of the upgraded Health Sensing System on Apple Watch Series 12 and Apple Watch Ultra 4.

“Redesigned with more capable optical and electrical sensors and larger, more power-efficient green LEDs, the sensing system unlocks deeper health and fitness insights,” Apple says.

The new hardware helps inform Apple’s new Readiness app. For that reason, you’ll need to upgrade to a Series 12 or Ultra 4 to experience the new Apple Watch app.

The new watches are available to pre-order now ahead of release on Friday.

Before the Readiness app actually arrives, you can see it in action in a few places.

First, the App Store listing is already live. This is to support redownloading the pre-installed app on Series 12 and Ultra 4 watches in case the app is deleted.

However, you still need a new Apple Watch to unlock the app. It’s not included on Apple Watch Series 11, Ultra 3, or SE 3 and earlier, even with watchOS 27.

This is from the App Store description:

• Get a score and a clear classification of your readiness, including Recover, Pace Yourself, Ready, or Go For It.
• See an explanation of relevant factors and tap through to associated apps.
• Add complications and Smart Stack widgets for convenient and glanceable insights.
• View additional details in the Fitness app on

You can also see the new Readiness app shown off in Apple’s Series 12 introduction video:

As for how the new Readiness app actually works, Apple has a new support document that explains everything you need to know.

As mentioned during the keynote, Readiness is based on a score of 0-10:

• Go for it: 8–10
• Ready: 5–7
• Pace Yourself: 2–4
• Recover: 0–1

Apple also explains how “Activity data, daytime and overnight vitals, and sleep data” all impact your Readiness score:

• Activity: Activity from both today and your recent history can impact your readiness score. Active calories, workout effort ratings, and Training Load data are all used to calculate the score. Increased activity in general can reduce your score, while steady or reduced activity raises it. Additionally, you might see your score go down during the day after a workout or activity.
• Vitals: Readiness considers the status of your daytime and overnight metrics from the Vitals app. When your vitals indicate you’re Notably or Slightly off, your score is reduced. When all of your metrics are Typical or Favorable, your score is raised. Higher-than-usual heart rate variability (HRV) can lead to Favorable vitals and a high readiness score.
• Sleep: Your sleep score from the previous night and your recent history can impact your readiness score. A low sleep score from poor-quality or inconsistent sleep can reduce your readiness score, while a high sleep score, or an improved sleep score, can raise your readiness score.

Sleep score has been a really helpful built-in feature, and readiness score will take it even further with new hardware.

It’s great to see Apple Watch introduce Readiness as a built-in app as part of the new Health Sensing System.

While it would be nice to have it on watches without upgrading, it’s understandable that the new system relies on the vastly upgraded heart rate monitor.

For folks not upgrading hardware, there are already ways to use health and fitness data to come up with a similar system as well.

Meanwhile, Apple is treating its latest hardware as a clear shot at the competition by just becoming a better Apple Watch in ways that count.

Apple Watch Series 12 is currently available for pre-order from $399. Apple Watch Ultra 4 is available for pre-order from $799. Both models launch in one week on September 18.