Although Ben Affleck has always stayed in shape for his movie roles, he hasn't really been known for being ripped and having bulging muscles throughout his acting career. However, he did turn some heads when he did pull-ups with his shirt off in his blockbuster movie The Town. 

To prep for his role in the blockbuster movie The Town, Ben Affleck worked with celebrity personal trainer Rehan Jalali and Walter Norton Jr., the Boston Celtics strength and conditioning coach. Affleck supposedly woke up at 4 AM every morning to workout for an hour and a half before he would go to the movie set. According to Bodybuilding.com, he did a very specialized workout to get ready for the movie. He did a lot of cardiovascular training mixed in with his resistance training. He did workouts like high knee walks and skips for 10 yards followed by lunges and even an inch worm exercise. In terms of his weight training, he would alternate high reps and low reps with both compound and isolation workouts. He did tons of torso work and abs work.

Doing rotational exercises and working on your torso is very important. Rotational exercises can determine if one side of your body is stronger and more mobile than the other side. Body asymmetry is one of the primary causes of injury and pain. It will also keep your body more mobile and in sync and improve spine mobility. Not to mention, doing a lot of rotational and torso exercises will really build up the core muscles and get them real defined.