Upcoming workouts can only be managed in the platform in which they are generated. This means if a workout has imported from TrainingPeaks, Final Surge, or 2PEAK, the workout must be deleted or modified in the platform in which it originates. After modifying a workout, these changes will automatically sync to your Stryd calendar.
If the workout is prior to the current day, you must delete the workout from the Stryd mobile app or PowerCenter.