In the workout settings, you have the ability to make a workout private (so that other users cannot see it), delete a workout, edit the title and facility, and export the workout into different file formats. To expose this menu, you'll need to select an individual workout from either your list or calendar view. Once you have clicked on your selected workout, locate the cog/gear icon (identified in the screenshot below) located next to your social media sharing icons. Clicking on the gear will expose a workout settings menu.
You can always reverse making a workout private by clicking on your workout settings. Deleting a workout is irreversible at this time.