Arnold Press guide
The Arnold Press, also known as the rotational shoulder press,
isolates the deltoids with little other muscle emphasis, with
exception of the triceps. It's a good idea to start out with a
light weight when first attempting this exercise, until your
muscles get used to the movements.
This exercise can be performed sitting or standing. It may be
beneficial to perform this exercise sitting with adequate back
support to reduce the chance of injury.
To begin, take a dumbbell in each hand and bring them up to your
shoulders as if you had just curled them. Your back should be
straight and your head should be facing straight forward. From
this position you should begin rotating the arms out away from
your body, while simultaneously lifting your arms up over your
head. By the time you are halfway through the movement your
elbows should be pointing away from your body.
At the top of the movement, the arms should be extended without
locking the elbows. From this position, retaining a fluid
movement, reverse the procedure and return to where the
dumbbells are level with your shoulders in front of your body.
Continue with the exercise until you've reached the designated
rep completion for your set.