TUESDAY, Nov. 20 (HealthDay News) -- People who start a walking program for their health get more out of it by using a pedometer, a device that counts their steps, a new study shows.

"People who use pedometers increase their physical activity by about 2,000 steps a day, about a mile," said study author Dr. Dena M. Bravata, a senior research scientist at Stanford University. "They also seem to lower their blood pressure more and lose more weight."

The conclusion, reported in the Nov. 21 issue of the Journal of the American Medical Association, comes from an analysis of 26 studies with a total of 2,767 participants. Most were observational studies, which means the researchers simply watched what the volunteers did, while eight had some scientific controls.

Pedometer users in the controlled trials increased their physical activity by 2,491 steps per day more than those who didn't use the devices. The comparable increase for pedometer users in observational trials was 2,183 steps per day.

Pedometer users also had their systolic blood pressure -- the higher number -- fall by an average of 3.8 millimeters. A 2-mm reduction is associated with a 10 percent reduction in stroke mortality and a 7 percent reduction in death from blood vessel conditions, Bravata noted. And pedometer users also reduced their body-mass index by 0.4 percent -- about 2.5 pounds for a 195-pound individual.

One valuable input of pedometer use was that it seemed to increase motivation for more physical activity. "The more sedentary you were, the more likely this tool was to help you," Bravata said. "The effect on workplace interventions was not as great, because the people who participate in workplace programs are higher baseliners."

The study does have limitations, Bravata noted. Only 15 percent of the participants were men, and the average duration of the trials was 18 weeks.

But it's generally agreed that most Americans need more physical activity. Two-thirds of U.S. adults are overweight or obese, and the U.S. Centers for Disease Control and Prevention estimates that only 45 percent of Americans get enough physical activity, usually defined as at least 30 minutes a day of exercise such as walking.

One major advantage of pedometer use in an exercise program is that it caters to the American quest for numbers, said James Hill, director of the University of Colorado Center for Human Nutrition and co-founder of America on the Move, an organization dedicated to increasing physical activity.

"We published a paper in 2003 which suggested using pedometers as tools to promote physical activity," Hill said. "Until then, a pedometer was just a tool to measure activity. A pedometer puts physical activity in terms of a number. You can watch it and manage your day in terms of physical activity."

Pedometers can be simple and inexpensive or sophisticated and expensive, Hill said.

"I recommend that you invest at least $15," he said. "I'm a simple guy, and I prefer a one-button model that simply pushes you back to zero. Some models put in stride length and mileage, but the simpler kind does very well."

More information

A guide to using pedometers is offered by the U.S. National Institutes of Health.

SOURCES: Dena Bravata, M.D., senior research scientist, Stanford University, Stanford, Calif.; James Hill, Ph.D., director, University of Colorado Center for Human Nutrition, Denver; Nov. 21, 2007, Journal of the American Medical Association

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