Garmin Coach and an unscored workout

You can't add the run to the workout.

I'm always very careful to start the correct workout from the coach widget and also end the workout by going to the end of it. How did you start the workout and did you go to the end of the workout? To end a workout early you just press the lap until the watch tells you the workout has ended and the timer will stop. If you want to continue running after that you just press resume.

It was the first time I had such a situation. Now I will be especially careful.

Thanks for your reply.

Nice!

It is possible, but it requires some work. 

Basically:

Log a short workout (1 second) that counts as the coach workout.

Download FIT files for both workouts and merge them.

Delete activities in Garmin Connect.

Upload the merged activity.

One question is if it really matters for coached plans. It will adapt to your performance and one missed workout will not make much of a difference. You still got the training and after the next ~3 workouts it will adapt to your new performance.