Dumbbell lying extension (across face)

Lie flat on a bench with your feet flat on the ground and your head at the end of the bench. Hold a dumbbell with both hands and extend your arms straight up above your chest, palms facing each other. Keeping your upper arms stationary, slowly lower the dumbbell in an arc behind your head until your forearms are parallel to the ground. Pause for a moment, then contract your triceps to bring the dumbbell back to the starting position. Repeat for the desired number of repetitions.