How to Do Supine Dumbbell Tricep Extensions

The supine dumbbell tricep extension is also known as the skull crusher exercise. This is an arm exercise that works the back of your arms, or triceps. The simple exercise is done with a barbell or dumbbells. Here are some guidelines for basic form as well as instruction on using dumbbell weights to do supine tricep extensions on a bench.

Instructions

    • 1

      Pick up your weights. Your palms should face down toward your feet as you hold the dumbbells. Lie on a bench with your arms, elbow and hands shoulder width apart.

    • 2

      Press your arms up, holding a dumbbell in each hand. This initial movement should look like doing a chest press with dumbbells.

    • 3

      Bend your elbows to lower your weights back down to the level of your forehead. Keep your elbows pointed toward the ceiling. Focus on flexing your triceps on the way down.

    • 4

      Raise your arms back up to the starting position. Flex your triceps on the way back up. Repeat this motion for the desired number of repetitions.

    • 5

      Lift 12 to 15 repetitions. Rest for 30 seconds before doing another set. Do a total of three to four sets.