The One-Arm Dumbbell Row is an effective exercise targeting the upper back and shoulders. Start by placing your left knee and hand on a bench for support. Keep your back flat and torso parallel to the floor. Hold a dumbbell in your right hand with your arm extended straight down. Pull the dumbbell upwards by retracting your shoulder blade, then bending the elbow until your upper arm is in line with your back. Squeeze the shoulder blade at the top of the movement, then lower the dumbbell back to the starting position. Repeat for the desired number of repetitions before switching arms.