Set up for the one arm prone incline dumbbell curl by setting an adjustable bench to an angle of around 30-40 degrees.

Grab a dumbbell with your weakest arm (usually your left) and position yourself with your chest on the back of the bench (prone position).

Your feet should be used for stability on the floor, your shoulders should be about level with the top of the bench and one arm should be hanging - holding the dumbbell with an underhand grip (palms facing up).

You can use the free arm for stability.

Put the tension on your bicep by slightly bending your hanging arm. This is the starting position for the exercise.

Keeping your elbow fixed, slowly curl the dumbbell up as far as possible.

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

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

Exercise Tips:

Keep the rep timing slow and control the weight on the way down.

Use a full range of motion by allowing the weight to go almost all the way down, while keeping the tension on the bicep muscle.

Keep your elbow fixed. Don't allow it to come forward as you curl the weight up. Only your forearm should be moving.