A psychiatrist on the show explained that at any given day, the man's serotonin and dopamine levels were not consistent with the average person's. He needed that adrenaline high in order to almost level out. He definitely had the sensation seeking trait because he was willing to risk his life in order to fulfill that desire for adrenaline.
I looked everywhere on the internet for information on this episode and cannot find it anywhere! Instead I found another video of the exact same sport from the episode. It really is amazing but entirely too dangerous for me!