As long as you're not gaining weight.. it's ok to not move.
I disagree. The body needs to move regularly to prevent muscle atrophy and for keeping up the heart, lungs and blood vessels' ability to keep your blood oxygenated even when you are sitting still.
I have been told by a doctor to exercise my arms more. I had an ache in my left elbow which I thought was a remnant from an old bicycle injury but I was told that it was probably from keyboarding.
The tissue in my elbow needs more blood to heal, and to get blood there I need to exercise it.