While you keep Strava connected, Watts Lab retrieves the following information through the Strava API within the permissions you grant.
- Strava athlete ID and profile picture URL
- Activity summaries including ID, name, type, date and time, distance, elevation gain, moving and elapsed time, speed, power and heart rate summaries, cadence, energy, and device/equipment information
- Second-by-second power, heart rate, cadence, speed, and elevation
- Route maps and start/end location coordinates
We do not retrieve information Strava does not provide or you have not authorized, and do not request segment records or second-by-second location coordinates. Strava profile picture URLs are used only to display your picture in the account menu and are deleted within 7 days of collection and periodically retrieved again while connected. We do not store FTP from your Strava profile. Your chosen display name is retained and is not replaced with your Strava name when connecting or reconnecting. Your Strava athlete ID is kept while connected.
Activity summaries, second-by-second records, route maps and coordinates, and exact start times received from Strava are deleted from our database and storage within 7 days of collection. Afterwards, only the activity's Strava ID, date, moving time and type (indoor/outdoor) remain, together with the following training records calculated by Watts Lab, until you disconnect Strava or delete your account.
- Training load and power/heart rate summaries for each ride
- Best power by duration
- Fitness metrics
- Training levels by zone
- Prescribed workout matches and performance results
Connected data is used for ride analysis, map display, and training recommendations. Disconnecting Strava in settings stops new collection and deletes imported Strava activities, derived analysis, and generated training plans.
The following features operate only when you choose them. Other features remain available if you do not use them.
- Write training results to Strava activities: when enabled in settings, we append a training log to your own matched activity descriptions. It contains the plan name, current/total weeks and training phase, workout name and completion indicator, this week's and cumulative completed/planned counts with progress, days until the goal, and the next workout's date, name and duration, written in Korean or English according to your language setting. Power, FTP and training-load values and links are never written. This requires additional Strava write permission (
activity:write). The existing activity description is read when writing but is not stored. Written content may be visible to other Strava users according to that activity's visibility settings. Disabling the feature stops future updates; existing content can be edited or removed directly in Strava. - Select an event course from Strava routes: when you select a saved route for an event plan, Watts Lab retrieves your route list and the selected GPX file through the Strava API and sends them to your browser, where course analysis runs. The list and route file are not stored. Only analysis results (distance, elevation gain, gradients, elevation changes, and major climbs) and the Strava route ID are saved with the event goal. Private routes require additional Strava permission (
read_all).
Routes and location information are handled as follows.
- Strava activity route maps and start/end coordinates: deleted with other raw data within 7 days of collection
- Saved Strava route lists and files: not stored
- GPX files uploaded as event courses: analyzed in your browser; the original file is not sent to the server. The filename, simplified course coordinates, and analysis results are saved with the event goal to display the course again
If you authorize activity read (ACTIVITY:READ) access when connecting Intervals.icu, or connect with an API key, Watts Lab imports completed cycling activities with measured power (raw_watts) from the Intervals.icu API while the connection remains active. The first import covers the last 90 days; later imports pick up newly uploaded activities. OAuth connections require calendar write (CALENDAR:WRITE) access. Existing connections without activity read access continue to send calendar events only until you reauthorize.
Eligible activities are Ride, VirtualRide, MountainBikeRide or GravelRide records whose source is ZWIFT, or OAUTH_CLIENT with an app or device name. Activities that reached Intervals.icu through Strava, and activities whose source cannot be confirmed, are not imported. Only time (time) and power (raw_watts) are requested and stored as second-by-second records; heart rate, cadence, location records and original files are not stored. File format is kept as metadata only. Intervals.icu activities do not change the FTP you set or your FTP mode (auto or manual).
Disconnecting Intervals.icu in Settings stops activity imports and calendar transfers and deletes the stored connection details, imported Intervals.icu activities and second-by-second records, and the power curves, training metrics and workout matches calculated from those activities. Training plans are not deleted; only matches with those activities and their evidence stored in plans are removed. Activities imported from Strava and your Strava connection are kept, but training metrics that combine multiple activities are recalculated from the remaining records and may change.
If you connected with OAuth, disconnecting asks Intervals.icu to revoke the app's access; if that request fails, the disconnection is not completed and you need to try again. If you connected with an API key, Watts Lab only deletes the stored key, so revoke the key in your Intervals.icu settings if you no longer want it to be usable.