Instructions:

1. Sit on an exercise ball with your feet flat on the ground and your knees bent at a 90-degree angle.
2. Hold a dumbbell with both hands and extend your arms straight up towards the ceiling.
3. Slowly lower the dumbbell behind your head, keeping your elbows close to your ears.
4. Pause for a moment, then raise the dumbbell back up to the starting position.
5. Repeat for the desired number of repetitions.