I religiously watched Headbangers Ball every Saturday. It was two hours of metal and a whole lot of headbanging.
BTW I'm still banging my head after all these years, but not as hard and long as I used to. Speaking from my personal experience, headbanging gets a lot harder after turning 30. I used to be able to go all night when I was young, but now I'm lucky to get in at least 30 minutes before my neck starts hurting.