If it works, this could be the best weight loss invention yet - the ability to easily burn almost 120 extra calories per hour while working at your computer.
The origin of this thinking comes from Dr. James Levine, an endocrinologist at the Mayo Clinic, who found that any incremental movement, even fidgeting, burns extra calories. From this, he extrapolated that even very light aerobic activity would cause the body to greatly increase the rate at which it burns calories, a process called non-exercise activity thermogenesis.
To study his hypothesis, he invented a computer workstation that can be used while walking slowly - very slowly - on a treadmill, and recently released the results of a small research study that evaluated how many calories this would burn.
The recent study included 15 obese individuals - 14 women and one man - in their forties who did no regular exercise. Their average Body Mass Index (BMI) was 32 and percent body fat was 52%. Using the treadmill at 1mph burned 119 more calories per hour during the study than sitting while working, which would indicate that walk-working for 2 to 3 hours per day could lead to a weight loss of about 45 pounds in a year according to Dr Levine.
The author acknowledged that the study was limited by several factors, including its short duration, which did not extend throughout an entire workday, the small number of subjects, and the concentration of women.
My personal sense is that while this is attractive in theory, I would rather separate work and exercise. I much prefer the mood enhancing qualities from the endorphins produced by a good aerobic workout over low level activity.
Primary source: The energy expenditure of using a "walk-and-work" desk for office-workers with obesity. BritishJournal of Sports Medicine online.