Lie flat on a bench while holding a dumbbell at arms length. Your arm should be perpendicular to your body. The palm of your hand should be facing towards your face as a supinated grip is required to perform this exercise.
Place your non lifting hand on your bicep for support.
Slowly begin to lower the dumbbell down as you breathe in.
Then, begin lifting the dumbbell upward as you contract the triceps. Remember to breathe out during the concentric (lifting part of the exercise).
Repeat until you have performed your set repetitions.