This looks relevant - getting call centre workers to do some brief - 10-min daily - exercise sessions.
they performed 10 different sets of exercises, including stretching (hamstrings, spinal column, forearms, and shoulders), joint mobilization (hands, wrists, shoulders, column, hips, knees and ankles) and relaxation.
They ended up feeling better with less fatigue and discomfort. Ok there are limitations to this study and its style, but I think it comes back to movement being good. In any case, at the least sitting on your behind all day is depressing. Movement makes you feel better and think better - as in the book Spark.
Anyway, the full text of the study is here:
Stretching and Joint Mobilization Exercises Reduce Call-Center Operators’ Musculoskeletal Discomfort and Fatigue