Walking and Working May Be Winning Combination for Weight Loss

ROCHESTER, Minn., May 16 -- Walking while you work may be an effective way to lose weight and improve physical conditioning.

A specially designed vertical workstation allowed 15 obese office personnel to work on a standard personal computer while walking on a treadmill. They more than doubled their energy consumption compared with the calories they burned while seated at a desk, said James A. Levine M.D., and Jennifer M. Miller of the Mayo Clinic, here.

When seated at a desk the average energy the subjects expended was 72 kcal/hour versus 191 kcal/hour when walk-working at the vertical desk, they reported online in the British Journal of Sports Medicine.

"The mean increase in energy expenditure for walking and working over sitting in an office chair was 119 (25) kcal/h (P <0.001)," Dr. Levine wrote.

At that rate, he said, an obese worker who spent two to three hours walking while working every day could lose more than 44 pounds (20 kg) a year without dieting.

Dr. Levine, an endocrinologist, has been promoting exercise while working since early 2005, when he reported in Science that non-exercise activity thermogenesis or NEAT was a key determinant of obesity or slimness.

Dr. Levine's thesis is that any movement from wiggling, to fidgeting, to shoulder shrugs burns calories and when he measured the amount of those unconscious movements, he found-not surprisingly-that calories burned tracked the level of movement.

A logical extension of that observation, he said, was a work station that encouraged movement. So he designed a treadmill with a platform to hold a laptop. Dr. Levine uses a similar vertical work station in his own office.

The study recruited 15 obese, sedentary individuals-14 women and one man-in a pilot study of the vertical work station, which was conducted in at the experimental office facility at the Mayo Clinic Research Center.

Body composition was assessed with dual x-ray absorptiometry.

The average age of volunteers was 43, average body mass index was 32, and percent body fat was 52%.

Energy expended was measured using a high-precision indirect calorimeter.

Energy measurements were collected from the volunteers in five different settings: lying motionless, seated in an office chair working at a computer, standing motionless, walking in 15 minute segments at varied speeds (one, two, and three mph), and working at the vertical work station at a self-selected treadmill speed.

Energy expenditure increased significantly with walking with each increment in velocity, he found, regardless of whether energy expenditure was expressed in absolute terms or relative to body weight (P <0.001 in all cases)," he wrote.

Compared with standing still, energy expenditure increased by 116 kcal/hour when walking at a speed of one mph, by 172 kcal/hour at two mph and by 225 kcal/hour at three mph (P <0.001 for all).

The authors acknowledged that the study was limited by its short duration, which did not extend throughout an entire workday, the small number of subjects, and the overwhelming majority of women in the cohort. Moreover, although the study demonstrated increased energy expenditure, it did not provide long term evidence of weight loss.