Target Muscles: biceps brachii
Set Up: Sit on a stability ball with your back straight and your feet flat on the floor. Hold a dumbbell in each hand and hang your arms at your sides.
Action: Bring the dumbbells up toward your chest by contracting your biceps. Rotate your wrists at the top of the move so that your palms are facing you. When you've come as high as you can, reverse the move and slowly lower the dumbbells back to the starting position. Do three sets of 8-10 reps.