He did the slalom so many times that he started to get bored. Go figure, he's walking for the first time in many years and already he's bored. "Okay Mark, challenge accepted. Tomorrow you're doing stairs."
Mark, who is paralyzed, is training for the Cybathlon. The Slalom is one of the 6 tasks. In this video, the overhead tether is only to catch Mark if he loses his balance. He is operating on battery power and controlling the exoskeleton with button presses with his right hand.