He does great when he is by a wall, but as soon as he hits the open area he tries to go flying down the arena, and unless I just let go of the lunge line I would be getting dragged for have my hand taken off. This has happened both times that I tried to lunge him, the second time I even set up a series of jumps to try and make like a fourth wall, but he just went flying through them and down the arena.
Any suggestions would be great, as he is a very high energy horse and I think lunging is going to have to be done to get the excess energy out of him that he can no longer expend in pasture time.