Seated Row
This exercise will help to strengthen your back muscles that can give you support and stamina with various activities, including sitting at your desk. It is still important to get up and move around, but this exercise can help to give your back more capacity to complete your tasks.
One advantage of the single arm row is that it encourages core muscle activation as well by resisting rotation. Activating the muscles involved with rotation (or in this case, anti-rotation) can be an important part of a healthy spine.