Meet Mark 'The Smashing Machine' Kerr, the undisputed, unstoppable champion of the world's most savage sport. No-holds-barred 'ultimate fighting' gained massive popularity in the US, even out-rating boxing and pro-wrestling, until it was banned in the mid-1990s.

With an inhuman capacity for inflicting and withstanding pain, Kerr is a modern-day gladiator capable of almost any savagery in order to survive and win. But as this documentary demonstrates, the price you pay in this arena is counted not only in physical scars. As Kerr explains with unexpected (to say the least) eloquence and honesty, doing whatever it takes to dominate in a brutal sport eventually takes its toll. The Smashing Machine is a visceral portrait of a man willing to sacrifice his relationships, his health - and nearly his life - to stay on top. It's raw and engrossing, but be warned, it's not for the faint-hearted, or even the mild-hearted.

Contains scenes that may offend some viewers