Instructions:

1. Sit on an exercise ball with a dumbbell in one hand, feet flat on the ground.
2. Slowly walk your feet forward, rolling the ball until your head, neck, and upper back are supported on the ball.
3. Hold the dumbbell at shoulder height with your palm facing forward.
4. Press the dumbbell upward until your arm is fully extended.
5. Pause for a moment at the top, then slowly lower the dumbbell back to the starting position.
6. Repeat for the desired number of repetitions, then switch to the other arm.