Guide
Intervals.icu ↔ Garmin — Full Sync and Troubleshooting
Garmin Connect is the main upstream for Intervals.icu. But sync breaks in real life: duplicate activities, missing FIT files, broken Wellness. Here's what syncs, what doesn't, and how to fix the typical failures.
What flies both ways
The integration is bidirectional but asymmetric. Workouts and wellness go from Garmin to Intervals.icu. Workouts (structured training) go the other way.
Activities, Wellness, HRV Status, Sleep
Every completed activity, RHR, overnight HRV, sleep stages, Body Battery, Training Readiness. Syncs within 5 minutes of a watch sync to Garmin Connect.
Workouts into the Garmin Connect calendar
Structured workouts (warm-up/intervals/cool-down with targets) appear in Garmin Connect → Calendar and on supported watches within seconds of push.
Connection
How to connect Garmin Connect to Intervals.icu
Set up once via OAuth, then it runs automatically. Important: if you change your Garmin password, the token invalidates — you have to reconnect.
Open Settings → Integrations
In Intervals.icu, click the profile icon → Settings → Integrations. Find Garmin Connect in the list → Connect.
Authorize via Garmin
A garmin.com OAuth window opens. Log in with the same email as Garmin Connect. Approve Intervals.icu access to activities and wellness.
Verify the first sync
Intervals.icu will start pulling the last 30 days of activities. It usually takes 5-15 minutes. A fresh workout appears in the list — confirms it's wired up.
Workout push
Send a workout from Intervals.icu to your Garmin
A workout from the Intervals.icu calendar arrives in Garmin Connect as a scheduled workout and automatically lands on the watch after the next sync.
Create the workout in the Intervals.icu calendar
Calendar → Add → Workout. Structure: warm-up → intervals (pace/HR/power target) → rest → cool-down. Save to a specific day.
Send to watch
Open the workout → Send to watch. Intervals.icu pushes it to Garmin Connect. In Garmin Connect → Training → Workouts the scheduled workout appears.
Watch picks up the workout
After the next watch sync (open Garmin Connect on your phone), the workout appears under Workouts on the watch. On the watch: Training → Workouts → select → Do Workout.
Supported devices: Forerunner 255/265/955/965, Fenix 6/7/8, Epix 2, Venu 3, Edge 530/540/830/840/1040. Older models (Forerunner 235, Vivoactive 3) don't accept structured workouts.
Common issues and fixes
Intervals.icu depends on Garmin Connect. Most failures are either on Garmin's side or caused by parallel integrations. Four scenarios cover 95% of support requests.
Activity didn't appear in Intervals.icu
The run is in Garmin Connect, but it's not in Intervals.icu even an hour later.
→ Settings → Integrations → Garmin Connect → Reconnect. If that doesn't help, check that the activity isn't marked private in Garmin Connect (global Privacy setting).
Duplicate activities
Intervals.icu records the same activity twice — usually with slightly different distance or duration.
→ Two parallel integrations are on (Garmin + Strava FIT upload, for example). Disable one in Settings → Integrations. Remove existing duplicates manually: Activities → select → Delete.
HRV Status and sleep aren't syncing
Activities come through, but the Wellness tab is empty. HRV Status, Body Battery, and sleep don't appear.
→ Settings → Integrations → Garmin Connect → Scopes. Make sure Wellness and Sleep scopes are enabled. If Garmin didn't grant those during the initial authorization — Reconnect with the full set.
Workout arrived on the watch with simplified structure
Complex rest-based intervals (e.g., "run until HR 140") became a simple time-based rest on the watch.
→ FIT-format limitation on Garmin's side. Rewrite the interval as time- or distance-based (2-min rest instead of rest to HR). Verify the workout in Garmin Connect → Training → Workouts before the watch sync.
Wellness data Garmin gives Intervals.icu
If you have a Garmin FR255 or higher / Fenix 7 / Epix, the Wellness subset is a strong advantage over other watches. Intervals.icu uses it for fitness forecast and weekly review.
Overnight HRV in ms, balance, 7/28-day trend. Used as a recovery and overtraining indicator.
Morning resting heart rate. A +5 bpm jump is a signal of under-recovery or an incoming illness.
REM, deep, light, awake. Intervals.icu shows sleep quality next to training load.
Garmin's integrated 0-100 score based on HRV, sleep, and load. Intervals.icu displays it per day and uses it in the forecast.
Where clean data goes next
With sync working without duplicates or gaps, Intervals.icu becomes a full source of truth. Next — analytics or AI coaching through the same loop.
Intervals.icu
CTL/ATL/TSB, zones, wellness trends, weekly review. Everything the coach sees, you see.
STAS + ChatGPT / Claude
STAS is the bridge between Intervals.icu and ChatGPT/Claude. The AI sees your Garmin workouts and wellness, can review runs, and build a plan.
Frequently asked questions
How do I connect Garmin to Intervals.icu?
In Intervals.icu → Settings → Integrations → Garmin Connect → Authorize. OAuth through garmin.com. After approval, activities flow from Garmin Connect to Intervals.icu within 5 minutes.
Why didn't my Garmin workout appear in Intervals.icu?
Three causes: (1) the watch hasn't synced with Garmin Connect — check the app; (2) Intervals.icu OAuth token expired — reconnect in Settings → Integrations; (3) the activity is private in Garmin Connect — remove the privacy flag.
How do I push a workout from Intervals.icu to Garmin?
In the Intervals.icu calendar, open the workout → Send to watch. It appears in Garmin Connect → Calendar → Workouts and on the watch after the next sync. Supported devices: Forerunner 255/265/955/965, Fenix 6/7/8, Epix, Venu 3.
Why do I see duplicate activities in Intervals.icu?
Usually — Garmin auto-sync and FIT upload (via Strava, for example) are both on at the same time. Pick one source in Settings → Integrations; disable the others. Remove duplicates in Activities — select and Delete.
Do HRV Status and sleep sync from Garmin?
Yes. With Wellness sync enabled, Intervals.icu receives HRV Status (ms), resting HR, sleep stages, Body Battery, and Training Readiness. This feeds the Wellness tab, the fitness chart, and the recovery prediction.
Can I delete an activity in Intervals.icu only, without touching Garmin?
Yes. Delete in Intervals.icu is local. But on the next sync the activity will come back from Garmin Connect. To exclude a workout permanently, use Exclude — the activity stays in Intervals.icu but doesn't count toward fitness or zones.
Related guides
Clean Garmin data → AI that understands it
STAS connects Intervals.icu to ChatGPT and Claude. The AI sees your Garmin workouts, HRV Status, and sleep — and reviews runs with the full context.
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