How to sync Garmin with Samsung Health, Strava and Hevy, no duplicates

The usual setup is a watch for runs and sleep, Strava for the social side, Hevy for lifting, and Samsung Health because it came with the phone. Each holds part of the week. Wire them together carelessly and you get the same run three times; wire them well and you get one timeline.

How does Health Connect route your data?

On Android, Health Connect is the shared store: dozens of data types across activity, body measurements, sleep, vitals and nutrition, with each app declaring separately whether it reads, writes, or both. Samsung Health, Garmin Connect, Oura, Whoop and Polar Flow all write to it. That is what makes a single picture possible without anyone re-logging anything. On iPhone, Apple Health plays the same role with the same shape.

The critical detail most guides skip: read and write permissions are separate, per app, per data type. An app that both reads and writes the same type is how duplicates are born. Garmin writes your run; Strava, if also granted write access, writes what it believes is a different run; something reading the store now sees two.

How do you sync Garmin with Samsung Health?

You mostly do not, directly. Garmin Connect writes to Health Connect; Samsung Health reads from it and writes its own data to it. The trick is deciding which of them owns which data type.

1. Install Garmin Connect and grant it write access in Health Connect for the types the watch measures: sleep, heart rate, HRV, workouts, steps.
2. Open Samsung Health's Health Connect settings and turn off its write access for those same types, leaving read on.
3. If the phone is also counting steps through Samsung Health, turn that writer off too; the watch is the better counter.
4. Check the next morning that one sleep record and one step total appear, not two.

If you prefer Samsung Health as the home screen for your data, that is fine: it reads everything Garmin wrote. What it should not do is write a second copy.

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Set one writer per data type

The rule that solves nearly everything: for each kind of data, pick exactly one app that writes it, and let everything else read.

Then audit it. Health Connect's own app lists, per data type, exactly which apps can read and which can write; walking that list once and turning off the writers you did not intend is twenty minutes that fixes months of noise.

• Open Health Connect, then Data and access, and go through each data type.
• For every type, note which apps have write access. More than one is a problem unless they measure different things.
• Turn write off for the app that does not own the sensor; leave read on.
• Delete the duplicated history for that type if the store offers it, so old doubles stop inflating averages.
• Check again after installing any new fitness app; most ask for write access by default.

Why does Strava show my Garmin run twice?

Strava's auto-sync loops. If Garmin pushes to Strava directly and both write to Health Connect, an activity can arrive twice by two different routes. Pick one route: the Garmin-to-Strava link for the social copy, and Garmin as the only Health Connect writer for the record. Strava's own Health Connect write access should be off.

Timezone and overlap. Duplicate detection generally works on start time and duration. Two records of the same run recorded by devices whose clocks differ slightly may not be recognised as the same activity by a naive reader.

Cardio inside a lifting session. A 70-minute Hevy session with a treadmill warm-up logged separately on the watch will be counted as two workouts unless something reconciles the overlap.

Does Hevy sync with Health Connect?

Hevy exposes your strength sessions directly, which is what a reader needs: sets, reps and load, not just a block of elevated heart rate. The important thing is that nothing else is also writing your lifting sessions. If your watch records the gym session as a workout too, you have a duration from the watch and the detail from Hevy for the same hour, and a reader has to merge them rather than count both.

Treat Hevy as the writer for strength and the watch's record of the same hour as a duplicate to be absorbed. The heart-rate trace from the watch is still useful as context; the session count is not.

Why does the load still not add up?

Load counted in incompatible units. The deeper problem, and the one permissions cannot fix: a heavy squat session and a tempo run both cost you, but no single app converts them to a common scale. This is precisely where the acute-to-chronic workload ratio stops working — the ratio is only meaningful if the load count is complete, and how much training load is too much explains what a complete count needs.

This is why a tidy Health Connect setup is necessary but not sufficient. It gives you one clean record of each session. It does not give you one number across them, and the one number is what the injury research is about; why fragmented fitness apps stall progress is the longer argument.

What about VO2max and recovery scores from two devices?

Derived metrics are a special case. Your watch's VO₂max estimate and its readiness score are written as its own data, and a second device will write its own, different estimates. Those are not duplicates to be removed; they are two opinions to be read side by side. Keep both, compare the trends, and do not average them. How the recovery scores differ is in Garmin vs Oura vs Whoop; what the VO₂max estimate means against your age is in what is a good VO₂max for my age.

What PeakU does with this

PeakU reads rather than writes, which is the only way to join this up without making it worse. It pulls sleep, HRV, resting heart rate, steps, weight and workouts from Apple Health or Health Connect, strength sessions from Hevy and runs from Strava, then reconciles them into a single timeline with overlapping records de-duplicated.

Load is then computed across everything on one scale, so the acute-to-chronic ratio reflects the whole week rather than whichever third of it one app happened to see. It writes its own workouts back so the rest of your apps stay in step — and because it is a reader, you keep logging exactly where you already log.

Hen Eytan · Founder, UPeak

Builds the UPeak apps and writes up the research behind them.