Thorsen won Denmark's Strongest Man in 1983. Thanks to his stature, he often plays imposing giants and villains in films who are somehow beaten by smaller opponents in a David and Goliath manner, although he has also played heroic characters such as Gunnar the legendary warrior in The Viking Sagas. His autobiography Stærk Mand i Hollywood (Strong Man in Hollywood) was published in 2007, and was very well reviewed. The first printing of the book reportedly sold out in 24 hours. Thorsen is an old bodybuilding partner and good friend of actor Arnold Schwarzenegger, who played Dutch in Predator, and he has appeared in many of Schwarzenegger's films, usually in minor non-speaking roles.