Wrestlers, unlike stunt performers, perform their choreographed competitions in one take in front of a live audience. Great wrestling is half complicated choreography and part improvisation, with wrestlers feeding off each other and the audience to produce a one-of-a-kind piece of art. During their careers, some wrestlers can make as much as $100,000 per night performing. Stunt performers usually work for film or television productions and are used as extras in scenes that require people to act out conflict or other physical actions. They are also needed when special effects are required but not available on set (for example, when a car needs to be crashed into a tree at high speed). Stunt performers must be able to walk away from such accidents unharmed. Some athletes who have performed stunt work include Paul Stanley, Sylvester Stallone, and Bruce Lee. The term "stuntman" is often used interchangeably with "stunt performer", but they are not the same thing. A stuntman performs his own stunts; a stuntwoman does not. Some male actors who have performed stunt work include Elisha Cook Jr. and Kiefer Sutherland. There is no specific training required to be a wrestler. However, some types of stunt work do require some form of martial arts training. Most wrestlers start out by working as bodyguards for larger celebrities or athletes during events or photo shoots.