How do I Delete a workout entered in error

To delete a specific Workout:

On the paired iPhone tap the Fitness icon, then "Summary" in the lower left corner. Then "Show More" in the Workouts section. Swipe left on the Workout you want to delete and tap Delete.

Go to the health app, go to Activity-Workouts, and click Show All Data. There, you can delete any of the workouts that have been logged.

Many thanks DELETE worked perfectly following your instructions

The workout remained in Watch. Is it possible to remove it from the watch too.