He told Mexican magazine 15a20 that he worried how he looked in comparison.
"After seeing how much Taylor works out for the movies, I thought, 'Well, everybody is really going to judge me now.' I always tried to think about positions where I could tense the muscles, and suck in my belly," he said, according to New York Magazine.
He decided to give Lautner a little competition for the upcoming 'Breaking Dawn' film.
"OK, it's the last one, I'm getting a six pack," he said he decided, and worked out "hard" for six months.
Fans can see if all that time in the gym paid off when 'Breaking Dawn - Part 1' hits theaters on November 18.
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