Gong Yoo went on a diet for three months to reduce his body fat. He learned the Russian martial art Systema for the film's fight scenes, and performed car chases, rock climbing and skydiving at the Han River without using stuntmen, for his role on The Suspect back in 2013.
Gong Yoo played the role of a father for the fourth time in "Train to Busan." In the past he played the role of a father in "The Suspect," "Silenced," and "A Man And A Woman.".
In 2016, Gong Yoo has resurgence in his career by starring in two major movies at the same time, Train to Busan (the first movie in 2016 to score 10 millions viewer) and The Age of Shadows (as the South Korea contender for the submission for the 89 Oscar for Best Foreign Movie).