Apple Watch, readiness & HRV
A readiness score for Apple Watch, without another wearable
WHOOP, Oura, Garmin and Polar made the morning recovery number popular: one score that tells you whether today suits a hard session or an easy one. Apple added its own version, Readiness, in watchOS 27. It only runs on the newest watches, though, and if you wear an older Apple Watch you may think you need a second wearable to get a score.
You don’t. Everything a readiness score is built from is already in Apple Health. Here is what goes into the score, how to read it without overreacting, and how to get one on the watch you already have.
Short answer
A readiness (or recovery) score compares last night’s sleep, your overnight vitals (HRV, resting and sleeping heart rate, breathing rate, temperature) and your recent training load with your own normal. Every recent Apple Watch records these. Apple’s built-in Readiness needs watchOS 27 and an Apple Watch Series 12 or Ultra 4, and other apps can’t read Apple’s score. On any other Apple Watch, an app that reads Apple Health, such as Keho or Athlytic, can calculate one without extra hardware.
What a readiness score is built from
Brands use different names (Recovery, Readiness, Nightly Recharge) and different weights, but the ingredients are nearly always the same three:
- Sleep. How long and how well you slept last night, and how the last few nights went.
- Overnight vitals. Heart rate variability (HRV), resting or sleeping heart rate, breathing rate, and where available temperature and blood oxygen.
- Recent training load. How much and how hard you trained over the past days compared with what your body is used to.
The key word is your. An HRV of 35 ms is neither good nor bad on its own. What matters is whether 35 ms is normal for you. Every serious readiness score learns your personal range over a few weeks and then asks how far this morning sits from it. That is also why a new score is shaky for the first week or two.
What your Apple Watch already records
If you sleep with your watch on, it saves nearly everything a readiness score needs to Apple Health:
| Input | What Apple Watch records |
|---|---|
| Sleep | Sleep stages (Core, Deep, REM, Awake) when sleep tracking is on; watchOS 26 added a nightly sleep score |
| Heart rate | Background readings about every five minutes while you’re still, plus one resting heart rate a day, estimated from awake rest |
| HRV | As SDNN, from short readings taken while you’re still, by default about every four hours, day and night |
| Breathing rate | Measured overnight |
| Wrist temperature | Overnight, on Series 8 or later and every Ultra |
| Blood oxygen | On models and in regions where the feature is available |
| Training | Every workout with its heart rate, the basis for training load |
Apple’s Vitals app already compares your overnight heart rate, breathing, temperature and blood oxygen with your typical range after seven nights. On older watches it stops there: it flags outliers but doesn’t turn them, your sleep and your training into one number.
Apple’s own Readiness in watchOS 27
Apple describes the feature in its support article “About Readiness”. The essentials, as checked on 28 September 2026:
- A score from 0 to 10 in four categories: Recover (0–1), Pace Yourself (2–4), Ready (5–7) and Go For It (8–10).
- Three drivers: your sleep score and recent sleep history, your daytime and overnight vitals, and your activity (active calories, workout effort ratings and Training Load).
- It needs at least seven nights of wear, last night slept with the watch, and your health details entered.
- It is available on Apple Watch Series 12 and Apple Watch Ultra 4 only.
Apple’s HealthKit documentation lists no data type for the score, so third-party apps can’t read it, display it or build on it.
Your options on an older Apple Watch
A dedicated wearable. WHOOP is the best-known choice: a membership that comes with its own sensor band, worn around the clock, with recovery, strain and sleep coaching in one system. If you want that whole system and don’t mind a second device, it does the job well. For an Apple Watch owner it means a second device and a membership on top of the watch you already paid for.
An app that reads Apple Health. Apps such as Keho and Athlytic calculate a score from the data your watch already saves. Nothing new to wear or charge. The honest limitation: older Apple Watches take HRV readings only every few hours, so the overnight HRV picture is thinner than from a device that measures continuously during sleep. Good apps compensate by averaging the night’s readings and leaning on sleeping heart rate as well.
So is a readiness app a WHOOP alternative for Apple Watch? If what you want from WHOOP is the morning recovery verdict, yes. If you want WHOOP’s hardware and its strain coaching, no app replaces that.
How to read your score sensibly
A readiness score is personal guidance from your own data. It is not a diagnosis, and it works best when you treat it as one input among several:
- Watch the trend, not the day. One low morning is information, not an instruction. Several low mornings in a row, with HRV below your normal and resting heart rate above it, deserve attention.
- Know what moves it. Short or broken sleep, alcohol, a late heavy meal, a hard session yesterday, travel and time-zone changes, heat, stress and feeling unwell all push the score down.
- Know when to ignore it. In the first weeks while your baseline forms, after a night without the watch, or when you know the cause (a late dinner) and feel fine.
- Your body gets the last word. If you feel unwell, rest, whatever the number says. If you feel great on a “Pace yourself” day, an easy start will tell you more than the score.
HRV usually carries the most weight, and it is the most misunderstood number. Why Apple Watch and Polar show different HRV values.
Get a readiness score on any Apple Watch with Keho
Keho reads your sleep, vitals and workouts from Apple Health and calculates a readiness score on your iPhone:
- Install Keho and allow it to read sleep, heart rate, HRV, resting heart rate, breathing rate, temperature, blood oxygen and workouts.
- Keep wearing your Apple Watch to sleep, with sleep tracking on.
- After about a week of nights your first score appears, marked as an early read. After about two weeks it rests on a full baseline.
The scale is deliberately the same as Apple’s: 0 to 10, with the levels Recover (0–1), Pace yourself (2–4), Ready (5–7) and Go for it (8–10). The score has three drivers, Sleep, Vitals and Activity, and shows which way each one pushed it. Every vital is judged against your own typical range from the last 49 nights, so you see which one is off, not just that the total is lower. You find the score on Home, in widgets, through Siri and, if you like, in a morning notification. If two or more overnight vitals drift from your normal at once, Keho gives you a heads-up.
It works with every Apple Watch that writes to Apple Health, and with Polar watches through Keho’s Polar Sync, which adds Nightly Recharge. Readiness is part of Keho’s Advanced Statistics, a one-time unlock that also comes with any other Keho purchase. If you use Apple Health only, you get 30 days free once your first score appears. All health data stays on your iPhone; there is no account.
Common questions
Does Apple Watch have a readiness score?
Yes, since watchOS 27, but only on Apple Watch Series 12 and Ultra 4. Older watches record the same kinds of data, and an app that reads Apple Health can turn it into a score.
Can other apps show Apple’s Readiness score?
No. Apple provides no HealthKit data type for it, so apps calculate their own score from the underlying data instead.
Is a recovery score from Apple Watch as good as one from WHOOP?
They measure at different times with different sensors, so the numbers won’t match, and neither is “the true” value. Consistency matters more: the same device, worn every night, compared with its own history.
Why is my score low when I feel fine?
Often a single cause, like a late meal or a short night, has lowered your HRV or raised your heart rate without you feeling it. Check which driver moved. If the cause is obvious and you feel good, train as planned and see how tomorrow reads.
Sources: Apple Support, “About Readiness” and “Track your overnight and daytime vitals with Apple Watch”; Apple, “Using Apple Watch to measure heart rate, calorimetry, and activity” (November 2024); Apple HealthKit developer documentation. All checked on 28 September 2026. Keho is an independent app and not affiliated with Apple, WHOOP or Athlytic.