Instructions:

1. Lie flat on a bench with your head at one end and your feet firmly on the ground.
2. Hold a dumbbell with both hands and extend your arms straight above your chest.
3. Keeping your arms straight, slowly lower the dumbbell behind your head in an arc motion.
4. Pause for a moment at the bottom, then raise the dumbbell back to the starting position.
5. Repeat for the desired number of repetitions.