Option 1: Use Dumbbells

Start with the dumbbells at your side.

Bring one dumbbell up toward yourself. Curl the dumbbell so that it is parallel with the ground.

Bring the other dumbbell up.
 

Option 2: Use Bar

 
Starting position. 

Bring bar up.  Do not lean to either side.


Finish. Lower bar back to starting position with controlled movement.