dumbbell lying one arm press v. 2

Lie flat on a bench with your back supported and feet flat on the ground. Hold a dumbbell in one hand with your palm facing towards your feet. Extend your arm straight up towards the ceiling, keeping your elbow slightly bent. Slowly lower the dumbbell down towards your chest, keeping your elbow close to your body. Pause for a moment at the bottom, then push the dumbbell back up to the starting position. Repeat for the desired number of repetitions, then switch to the other arm.