CHEST

"There are three chest exercises that should always be done," Arnold says. "The bench press, the incline bench press at different angles, and the dumbbell flye."

Arnold was known for the size, shape, and extreme width of his chest, which he credits to an extreme stretch on the flye. "The flye is the exercise that gave me the full pectoral muscle development," he says.

"Remember, with muscles, the important thing is always to get the stretch and the flex. So to me, going all the way out [on the dumbbell flye]—as far as you can go—and then coming in and touching the dumbbells together and flexing like you're doing the most muscular pose made all the difference. That exercise couldn't be replaced by any machine."