Your ring and your watch,
finally reading from the same page.

No. One is enough, and the price is the same either way.

What changes is which screens fill in. Oura alone gives you sleep stages, efficiency, readiness, temperature deviation, daytime stress, resilience and cardiovascular age — the overnight and all-day picture. Garmin alone gives you VO₂ max, training load, recorded workouts with GPS and heart-rate zones, and weight from a connected scale — the training picture. Apple Health alone covers the basics from an Apple Watch or anything else that writes to it.

Together they cover each other's blind spots, which is the setup the app was built around. But no screen is empty because you only own one device — we hide what a source genuinely cannot supply rather than showing you a card with a dash in it.

Because Garmin does not offer a self-serve API for individuals. Their developer programme is aimed at companies, with an approval process and commercial terms behind it.

intervals.icu already holds an approved Garmin connection, is free, and is widely used by endurance athletes. You connect Garmin Connect to intervals.icu once, then give us your intervals.icu athlete ID and API key. Your Garmin data flows Garmin → intervals.icu → here.

The honest cost of that route: it carries what intervals.icu has a field for. Total sleep, sleep score, sleep quality and average sleeping heart rate come through. Sleep stages do not — there is no field for them in the schema, so they are lost in transit rather than missing from your watch. The Apple Health route below is the way to get them.

Your watch measures them; the route they take to reach us cannot carry them. intervals.icu has no deep/REM/light fields at all — we checked the full wellness schema rather than assuming.

The fix is Apple Health. Garmin Connect writes sleep stages into Apple Health on your iPhone, and an export app pushes them to us from there. Set that up and the stage timeline fills in on a Garmin-only setup.

One wins, and the app tells you which. Every number carries a small badge naming the source that actually produced it — O Oura, G Garmin, I intervals.icu, A Apple Health, S smart scale, M entered by you, C calculated here.

We never average two devices into one figure. Blending a sleep score from one with stages from another would describe a night neither device measured. One source per metric, per day, named on screen.

You set the order in Setup, separately for overnight metrics (sleep, HRV, resting heart rate, readiness) and all-day ones (steps, respiration, SpO₂, calories). By default Oura goes first, because it is worn around the clock by design.

No. The setting is a priority order, not an exclusion.

Whichever device you put first is used wherever it has data, and the other still covers the days it missed. A night your ring spent on the charger shows your watch's number, badged G, rather than a gap in the chart — and the app puts a note on the screen saying the fallback filled in, so a number that quietly changed source never goes unexplained.

That matters more than it sounds: a preference that switched a device off entirely would mean choosing a favourite silently cost you every day the other one covered.

It will appear twice, and both will be labelled “also on another device”.

We flag the overlap rather than picking a winner, because the two genuinely disagree — different sensors, different calorie models, and Garmin has GPS distance where Oura has none. Neither is wrong, and silently deleting one would hide a real difference from you.

Sessions starting within twenty minutes of each other on different devices are treated as the same workout. Back-to-back sessions on the same device are left alone.

Three of the rings and two of the age cards. Everything else is passed through from your device unchanged.

Rebound, Effort and Charge are ours, scored against your own recent baselines rather than a population — so the same value means the same thing whether your HRV runs at 30 ms or 90. Fitness Age and the VO₂ percentile implement the FRIEND registry treadmill norms; Heart Age implements the published Framingham cardiovascular risk model from your blood panel.

The app shows the arithmetic. Open any ring and it names every input, the device that supplied it, and — for our own scores — the exact formula. A health number you cannot interrogate is worth less than one you can.

Because they are two different calculations, and neither is “the” answer.

Ours inverts one published dataset: the age at which your VO₂ max equals the population median for your sex. It therefore moves with VO₂ max alone, and near the top of the range it moves fast. Garmin's comes from Firstbeat's model, which blends in resting heart rate and body composition and is calibrated against a different population, so it sits closer to your real age by construction. Expect ours to read younger.

The percentile shown beside it is the number to trust — it makes no modelling assumptions beyond the reference dataset itself.

No — that one is Oura's own measurement, passed through untouched. The ring reads arterial stiffness from the shape of the pulse waveform in its optical sensor.

It is the one card with no fallback. Neither Garmin nor Apple Health publishes an equivalent, and resting heart rate and HRV cannot stand in for it — they track autonomic tone, which is a different thing entirely. Without a ring the card says so rather than estimating something it cannot measure.

Your recent numbers and your baselines. Nothing else.

It does not receive your name, your email, your raw history, or any data belonging to another user — there is no shared pool to draw on. Each written overview lists the exact values that went into it, so you can check what it was told.

When the AI is unavailable, a rule-based writer takes over and the badge changes from AI to auto. The card still appears and still says something true about your day; it just says it in fixed sentences.

Yes, through Apple Health — an Apple Watch, a Whoop, a Fitbit, a smart scale, anything that writes there. Your phone pushes the metrics you choose to a private URL we issue you.

It is a one-way push from your device. We hold no Apple credentials, cannot read your phone, and cannot request anything you have not configured it to send. Resetting the URL in Setup stops it immediately.

Apple Health also sits behind the direct integrations rather than competing with them: where Oura or Garmin already has a reading, theirs wins, and Apple fills the gaps they leave.

It stays. Readings are stored per day with the source that produced them, so a year of Garmin followed by a year of Oura reads as one continuous history with the badges changing partway through.

Baselines adapt on a rolling window rather than being fixed at signup, so scores measured against “your normal” recalibrate to the new device within a few weeks. Expect some step change at the switch — two devices genuinely measure differently, and pretending otherwise would be the dishonest option.

Every thirty minutes while you are connected, plus on demand. Your first sync pulls roughly three months of history so the charts have something to say on day one.

Your data goes to the AI provider only when you use an AI feature, and only as the summarised numbers described above. It is never sold, never shared with advertisers, and never used to train models. The full detail is in the privacy policy, and the calculation sources are set out in section 3 of the terms.