How to combine Garmin, Samsung Health, Strava and Hevy without double-counting

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.

Health Connect is the hub, and it is one-directional per app

On Android, Health Connect is the shared store: more than fifty data types, 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.

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.

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.

Sleep, HRV, resting heart rate: your watch's own app. It owns the sensor; nothing else should be writing these.

Runs and rides: whichever of the watch app or Strava you consider canonical — and then turn write access off for the other. Most people should let the watch write and let Strava read, because the watch has the raw data and Strava has a copy.

Strength sessions: Hevy. Nothing else knows your sets.

Steps: one source only. Phone and watch both counting is the most common duplicate of all, and it inflates every daily total downstream.

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.

Watch for the second-order problems

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.

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.

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.

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 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.