working with exercise

I read about the article exercise by running on threadmill and doing office work by typing the computer. It really is the good idea because by walking-and-working, energy expenditure might increase by 100 kcal/hour compare to sedentary life style. But , when i look back to my office people which comprise largely by ahem, ahem races. They are so lazy to get up to take documents , some might even use the chair kicking around to near by places to take document. I can't imagine if the office replace by this threadmill and computer system. I think more then 50% will take mc.
By the way, if this system is to be implemented, the best way is provide the threadmill will dynamo power and let the user choose the computer to be fully powered by dynamo(all by your hard force) ,partially supplement or minimal supplement . I think if this system fully implemented, there will be lots of healthy person but productivity might reduced because a lot of people cannot concentrate and think during exercise .