To begin, stand up with a dumbbell held in one hand. Your feet should be about shoulder width apart from each other. Now fully extend the arm with the dumbbell over your head. Tip: The small finger of your hand should be facing the ceiling and the palm of your hand should be facing forward. The dumbbell should be above your head.
This will be your starting position.
Keeping your upper arm close to your head (elbows in) and perpendicular to the floor, lower the resistance in a semicircular motion behind your head until your forearm touch your bicep. Tip: The upper arm should remain stationary and only the forearm should move. Breathe in as you perform this step.
Go back to the starting position by using the triceps to raise the dumbbell. Breathe out as you perform this step.
Repeat for the recommended amount of repetitions.
Switch arms and repeat the exercise.
Variation: You can perform this exercise with a rope attached to a low pulley.
Alternative Exercises For Standing One-Arm Dumbbell Triceps Extension