Is to install a treadmill at each desk. Read about it in this article–“I Put In 5 Miles at the Office. Excerpt:
Terri Krivosh, a partner at a Minneapolis law firm, logs three miles each workday on a treadmill without leaving her desk. She finds it easier to exercise while she types than to attend aerobics classes at the crack of dawn.
More here (Recommendation: watch the Good Morning America segment listed there):
Dr. James Levine of the Mayo Clinic came up with the idea of a “Treadmill Desk”. The idea is to slowly walk on a treadmill while working at a desk built around the treadmill…a Treadmill Desk.Dr Levine’s research revealed that on the average his subjects burned 100 extra calories every hour while walking slowly — at 1 mile per hour — than while sitting in a chair.
Dr. Levine believes that if individuals were to replace 8 hours a day of sitting at their “normal” desk with a Treadmill Desk, and if other components of energy balance were constant, a weight loss of 57 pounds a year could occur.
More about it here.