I know the adolescent GSD is difficult, but in my view, it isn't going to help by pushing the dog outside - that can lead to other problems - excessive barking, boredom. Instead I suggest you alternate training sessions (short), playtime (tug, fetch) and quiet time (he practices his down/stay).
I didn't say that I was going to push him outside. I work with him most throughout the day; training is interwoven into everything I do in his presence, especially the NIFIFF treatment. Once in a while he needs to be crated since I also have a life of my own. And an outdoor kennel would be just the alternative for a crate and to eat his meaty bones. Other than that he is always inside with us.
Deja, GSD, sable WL, female, born 11 / 2013
Cam, Rough Collie, sable, male, born 8/2015