If you’re choosing a wearable — or already own one and wonder why an app isn’t seeing all your data — the honest answer is that “works with Apple Health” means something different on every device. Garmin, Apple Watch, Oura and WHOOP all write to Apple Health. They do not write the same things, and the gaps are exactly where people get caught out.
Here’s the short version, then the detail and the catches.
The one-line summary
Apple Watch writes everything natively. Garmin writes workouts and active energy but keeps HRV internal. Oura writes sleep, HRV and active energy, with motion-estimated workouts. WHOOP writes calories and heart rate only when attached to a recorded workout — and never writes HRV at all.
The comparison, at a glance
| Data type | Apple Watch | Garmin | Oura | WHOOP |
|---|---|---|---|---|
| Workouts | Yes (native) | Yes | Yes* | Yes |
| Active energy | All day + workouts | All day + workouts | Daily movement | Workouts only |
| Heart rate | Continuous | Frequent | Resting / daily | Workouts only |
| HRV | Yes | No | Yes | No |
| Sleep | Yes | Yes | Yes (detailed) | Yes |
*Oura workouts are estimated from motion or imported from another app — it has no GPS or continuous heart rate during exercise.
Apple Watch: the complete picture
No surprise — Apple’s own hardware writes the most granular data, and there’s no third-party sync step to break. Workouts, continuous heart rate, HRV, resting heart rate, sleep, and active energy throughout the day all flow straight into HealthKit at the moment they’re recorded. If completeness of data is your only concern, the Apple Watch is the benchmark the others are measured against. Its weaknesses are battery life and wrist-based HRV that’s less accurate overnight than a ring — but for sheer breadth of HealthKit data, nothing beats it.
Garmin: everything except HRV
Garmin writes a strong set to Apple Health: workouts (with GPS and on-wrist heart rate), heart rate, resting heart rate, sleep, and active energy — both during workouts and across the day. For energy expenditure and training load, Garmin is excellent.
The one deliberate gap is HRV. Garmin keeps its HRV Status inside the Garmin ecosystem and does not write it to Apple Health. So if you use an app that wants your HRV to assess recovery, a Garmin alone won’t hand it over — you either read it in Garmin Connect and log it manually, or pair the Garmin with a device that does write HRV.
Oura: rich data, motion-estimated workouts
Oura writes the most for recovery: detailed sleep stages, HRV, resting heart rate, body temperature, respiratory rate, steps, and active energy. Workouts exported from Oura contribute to both the Move and Exercise rings — the Exercise ring by duration, the Move ring by active calories. So yes, Oura workouts and their energy do reach Apple Health.
The catch is precision. A ring has no GPS and no continuous heart rate during exercise, so Oura’s workout calories are estimated from motion or imported from whatever recorded the session. That’s a perfectly good daily energy-balance signal, but it’s not the same as a chest-strap or wrist-HR workout. For overnight HRV, Oura is arguably the best of the four; for measuring the intensity of a specific session, it’s the weakest.
WHOOP: calories, but only for workouts you record
This is the device people misunderstand most, and it’s the detail worth getting right. WHOOP writes sleep, resting heart rate, blood oxygen, and — for workouts — active energy, heart rate, and its Strain value to Apple Health. The activities sync correctly with start and end times, duration, and calories.
But here’s the structural quirk, confirmed in WHOOP’s own support docs: disabling WHOOP from writing Workouts to Apple Health also stops it writing Active Energy and Heart Rate, because WHOOP only writes those values as data associated with a Workout. In other words, WHOOP’s calorie burn only reaches Apple Health for sessions it sees as workouts. An hour of activity that WHOOP didn’t log as a workout writes no active energy at all.
The rule for rings and straps: the burn only counts if you record the session. Passive all-day wear builds your recovery data, but it won’t put a run’s calories into Apple Health on its own.
WHOOP also doesn’t write HRV. Apple stores HRV as SDNN while WHOOP measures it as RMSSD, so rather than write a mismatched value, WHOOP omits HRV from the sync entirely. If you want your WHOOP HRV in another app, you currently read it in the WHOOP app or enter it by hand.
The active energy question, answered
Because this is the part that trips people up: all four devices can put active energy into Apple Health — but through different doors.
Apple Watch and Garmin write active energy continuously through the day and during workouts. Oura writes daily movement energy plus any workout it records or imports. WHOOP writes active energy only as part of a recorded workout. So if your goal is for an app to see the energy you burned on a run, the safe move on a ring or strap is simple: record the session. Don’t assume that wearing the device through a run is enough — on WHOOP especially, an unrecorded run contributes nothing to your HealthKit energy total.
How to set it up so nothing goes missing
Four steps to make sure your device’s data actually lands in Apple Health — and that any app reading HealthKit gets the full picture.
Turn the Apple Health connection on in your wearable app.
In Garmin Connect, Oura, or WHOOP, find App Integrations or Settings, select Apple Health, and enable it. Choose “turn on all” rather than cherry-picking categories — it’s easier to trim later than to discover a month of missing data.
Confirm Workouts and Active Energy are both on.
These are the two that matter for training. On WHOOP they’re linked — switching off Workouts silently switches off Active Energy and Heart Rate too, because WHOOP only writes those as workout data.
Record your sessions — don’t rely on passive wear.
A ring or strap only writes workout calories for sessions it recognises. Start a recorded activity, or let auto-detection catch it, so the workout and its energy reach Apple Health. This is the single most common reason a run’s calories don’t show up.
Set a priority source if you wear two devices.
If a watch and a ring both write steps or workouts, you may see duplicates. Apple Health doesn’t double-count calories — it uses a priority system — but setting your preferred source in Health keeps totals clean and predictable.
What this means for any app reading your health data
The reason all of this matters: any coaching, nutrition, or recovery app that reads Apple Health is only as good as what your device wrote into it. An app can’t read HRV that Garmin never exported, or calories from a run WHOOP never logged as a workout. The data ceiling is set at the device, not the app.
That’s also why pairing devices works so well: a Garmin (great workouts and load, no HRV) alongside an Oura (best-in-class HRV) gives an app the complete substrate — load from the watch, recovery from the ring. The app reads both from one place. The trick is just making sure each device is actually writing the part it’s good at.
“Works with Apple Health” isn’t a yes/no. It’s a list — and the gaps in that list decide what any app can ever know about your training.
Kovr reads it all from one place — whatever you wear.
Garmin, Apple Watch, Oura, WHOOP — Kovr reads workouts, active energy, sleep and HRV straight from Apple Health, and where your device holds HRV back, you log it in seconds. Then instead of a wall of numbers, it gives you one honest read on the day, in the language a coach would use.
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Frequently asked questions
Does Oura write workouts and active energy to Apple Health?
Yes. Oura writes sleep, HRV, resting heart rate, steps, and active energy to Apple Health, and workouts you record or import contribute to your Move and Exercise rings. The catch is that Oura has no GPS or continuous heart rate during exercise, so its workout calories are estimated from motion sensors or imported from another app — useful as a daily energy signal, less precise than a recorded watch workout.
Does WHOOP write calories to Apple Health?
Yes, but only for workouts. WHOOP writes active energy and heart rate to Apple Health only as data attached to a recorded workout. If you disable Workouts in WHOOP’s Apple Health settings, it also stops writing Active Energy and Heart Rate. So you must record the session in WHOOP for its calorie burn to reach Apple Health.
Do Oura and WHOOP write HRV to Apple Health?
Oura writes HRV to Apple Health. WHOOP does not — because Apple stores HRV as SDNN while WHOOP measures it as RMSSD, so WHOOP omits it rather than write a mismatched value. If an app needs your WHOOP HRV, you currently have to read it in the WHOOP app or enter it manually.
What does Apple Watch write to Apple Health?
The most complete set of any device, natively: workouts, continuous heart rate, HRV, resting heart rate, sleep, active energy throughout the day, and more. Because it is Apple’s own hardware there is no third-party sync step, so the data is the most granular and reliable of the four.
Does Garmin write HRV to Apple Health?
No. Garmin writes workouts, heart rate, resting heart rate, sleep, and active energy to Apple Health, but keeps its HRV Status internal to the Garmin ecosystem. To use Garmin HRV in another app you generally have to read it in Garmin Connect and log it manually.
Why does the same workout appear twice in Apple Health?
If two apps both write the same activity — for example an Apple Watch records a run, then WHOOP imports it and writes its own version back — you can see two entries. Apple Health does not double-count calories; it uses a priority system to decide which source to surface. Set a priority data source, or turn off duplicate write permissions, to keep totals clean.
Will a nutrition or coaching app see my ring or strap workouts?
Yes, as long as the workout reached Apple Health. Any app with HealthKit read permission sees the workout and its active energy once your device has written it. The requirement is that you actually recorded the session in your wearable’s app — passive all-day wear alone does not create a workout entry, so the burn from an unrecorded run will not appear.
Sources cited
- WHOOP. Apple Health Integration. WHOOP Support. View reference
- Oura. Apple Health Integration. Oura Support. View reference
- DC Rainmaker (2024). WHOOP exporting to Apple Health: how it actually works. View article
- Garmin device documentation on HRV Status and Apple Health data sharing.