Chris and Amy have been dating for a year. They are about to graduate high school, and Amy decides that it is best if they break up. She reasons that they are going to be at different colleges, and long term relationships never work. Chris takes the news very hard. He decides to join a gym and take out some stress by working out. A year later, Amy and Chris run into each back home and Chris is now in much better shape due to working out.
What defense mechanism did Chris use to help cope with the breakup?