Why Does Strava Say My .FIT File Is Corrupted?

If upon uploading an activity from your Garmin device you see an error message telling you that your upload was a "partially corrupted file, could be truncated," this means that there was some recording error on your device, and the file is at least partially corrupted. Strava has retained as much information as possible from the file, and that data will now be available on your Strava account. If a portion of your activity is missing from the upload, there's unfortunately no way to recover the remainder. It might help to reset your GPS device, although these errors occur relatively infrequently. If you have any additional questions, please create a support ticket.