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The Apple Watch Vitals app, explained

Vitals takes five overnight metrics, learns your typical range over about a week, and flags anything outside it. The design choice worth understanding is that it never tells you what an outlier means, and that is deliberate.

Updated August 8, 20269 min readWritten by Reviewed by Daniel Okonkwo

Vitals arrived in watchOS 11 and is the quietest genuinely good feature Apple has shipped in health. It does one thing: takes the numbers your watch already records overnight, learns what is normal for you, and flags when something falls outside that. No score, no advice, no coaching.

The five metrics, and why these five

Heart rate. Your overnight rate is the cleanest cardiovascular number you produce, because you are lying still with no caffeine, stress or movement confounding it.

Respiratory rate. Breaths per minute while asleep. Remarkably stable person to person night to night, which is precisely what makes a change worth noticing.

Wrist temperature. Series 8 and later only. Reported as a deviation from your own baseline rather than an absolute temperature, which we unpacked in Apple Watch wrist temperature.

Blood oxygen. The awkward one. Apple Watches sold in the US after 18 January 2024 shipped without it following the Masimo patent dispute, so a large share of US users have a four-metric Vitals app and no way to change that.

Sleep duration. Included because a short night moves the other four, and without it an outlier would be unreadable.

How “typical” is decided

Vitals does not compare you to a population. It watches roughly a week of your nights, builds a personal range for each metric, then marks each subsequent night Typical or Outlier against your own history. Apple says the classification algorithm was developed from the Apple Heart and Movement Study.

This is the right design. Population normal ranges for HRV and respiratory rate are so wide as to be useless for an individual: a resting heart rate of 48 is superb for one person and a warning sign for another. The only useful comparison is against yourself last month.

What Vitals will not do, on purpose

It will not tell you what an outlier means. Two metrics out of range is the same display whether you are getting ill, drank three glasses of wine, ran a hard session yesterday, slept in a hot room or flew across four time zones.

There is a real argument for that restraint. The same physiological pattern genuinely does have many causes, and an app that guessed would be wrong often and alarming occasionally. Apple has been consistently conservative about anything that reads as a medical claim.

There is also a real cost. A flag with no interpretation puts the analysis back on you, and most people looking at two amber dots at 7am do not have a framework for what to do next. Our deep dive on what a rising resting heart rate actually predicts is largely about how hard that inference is, and how many of the alerts turn out to be wine and travel.

Vitals is not a recovery score

Worth stating plainly, because the two get conflated constantly. Vitals shows five signals side by side and says whether each is normal for you. A recovery score weighs those signals against each other, resolves the contradictions, and produces one number you can act on before coffee.

The Apple Watch still ships no recovery or readiness score of any kind, which we went through in does the Apple Watch have a readiness score. Vitals is the closest Apple has come, and it stops one deliberate step short.

If your Vitals app is missing metrics or showing nothing at all, the usual causes are covered in Apple Watch not tracking sleep, since every Vitals metric depends on the watch registering a night in the first place.

Frequently asked questions

What does the Apple Watch Vitals app measure?

Five overnight metrics: heart rate, respiratory rate, wrist temperature, blood oxygen and sleep duration. Which ones you see depends on your model. Wrist temperature needs Series 8 or later, and blood oxygen is unavailable on Apple Watches sold in the US after 18 January 2024 because of a patent dispute.

What does an outlier mean in the Vitals app?

It means one or more of your five metrics fell outside the typical range Vitals learned from your own previous nights. It does not mean anything is wrong. Vitals deliberately offers no interpretation, because the same outlier can be produced by illness, alcohol, a hard workout, a hot room, travel or a late meal.

How long does the Vitals app take to set up?

About seven nights of wearing the watch to bed. Vitals needs that history to establish your typical range for each metric before it can classify a night as Typical or Outlier. Until then it collects data and shows no classification.

Is the Vitals app the same as a recovery score?

No, and the difference is the point. A recovery score combines several signals into one number and tells you what to do. Vitals shows five signals separately, tells you whether each is normal for you, and stops there. It is a dashboard, not a verdict.

Why does Vitals need me to wear my watch to sleep?

All five metrics are sampled overnight, when you are still and unstimulated. That is the only time of day when readings are comparable night to night, which is what makes a personal baseline meaningful in the first place.

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