TRICEPS: OVERHEAD EXTENSIONS & ROPE PUSHDOWNS For the back of the arms we’re going to go in opposite directions. First we’re going to go up with two arm overhead extensions. You can use a heavy dumbbell or a barbell, whichever you’re more comfortable with. Then we’re going to push down, as in rope pushdowns. The rope will allow you to separate the ends so you can put an extra squeeze on the long head of the muscles. CORE: CRUNCHES & HYPEREXTENSIONS Notice I didn’t say abs. For our .