Dumbbell seated alternate hammer curl on exercise ball

Sit on an exercise ball with your feet flat on the ground and your back straight. Hold a dumbbell in each hand with your palms facing your body and your arms fully extended. Keeping your upper arms stationary, exhale and curl one dumbbell up towards your shoulder while keeping your palm facing your body. Continue to raise the dumbbell until your biceps are fully contracted and the dumbbell is at shoulder level. Hold the contracted position for a brief pause as you squeeze your biceps. Inhale and slowly lower the dumbbell back to the starting position. Repeat the movement with the opposite arm. Continue alternating arms for the desired number of repetitions.