Second Effort is a 1968 sales training film starring Vince Lombardi,[1][2] the Hall of Fame head coach of the Green Bay Packers.

The film also featured veteran character actor Ron Masak and other members of the Green Bay Packers organization, including offensive lineman Jerry Kramer.

Many quotes and aphorisms commonly associated with Lombardi appear in the film, such as "mental toughness is the essential key to success" and "confidence is contagious, and so is the lack of it".

Australian former rugby league footballer Terry Fearnley was "mesmerized" by Second Effort after being shown the film as part of a corporate conference held by General Motors Holden.

Inspired by Lombardi and the film, Fearnley and Gibson would travel to the U.S. to study under American football coaches, and would bring back training techniques that would revolutionize rugby league in Australia.