"The guy is still in premium shape," LaBeouf tells PEOPLE. "You don't want to be standing next to Harrison Ford and not be jacked also."
In regards to how seriously he is taking his workout schedule and his new role: "It's not like I'm making the Nutcracker play at my school. This is film history. I don't just owe it to everybody involved in the franchise – I owe it to everybody who's ever been a fan of Indiana Jones. I realize how important this is."