Set up for the one arm seated hammer curl by grabbing a flat bench or adjustable bench and placing a dumbbell at one end. If you're using an adjustable bench, adjust the back to a 90 degree angle.

Sit on the end of the bench with your feet out in front of you and your knees together.

Pick up the dumbbell and let it hang by your side with your palm facing your body (neutral grip).

Use your other arm to stabilize your body.

Bend the arm slightly to take the tensioninto the bicep. This is the starting position for the exercise.

Keeping your back straight and your elbows tucked in at your sides, slowly curl up the dumbbell up as far as possible.

Squeeze the bicep muscle hard, and then slowly lower the dumbbell back to the starting position.

Repeat for desired reps, and then repeat on the other arm.

Exercise Tips:

As a general rule, always work the weakest part of your body first. For most people this will mean doing the left arm before the right.

Keep your body fixed throughout the movement.Do not swing back. Only your forearm should be moving.

The rep timing should be slow and the weight should be controlled on the way down.