The pedometer, a simple and inexpensive step-counting device, significantly increases daily activity levels and even promotes weight loss, according to a recent study directed by Dena Bravata, a senior research scientist at Stanford’s School of Medicine.

Bravata and her team of researchers analyzed study results from 2,767 people, mostly overweight and inactive women, who agreed to keep records of their physical activity while using a pedometer over an 18-week period. On average, the study found that the participants using pedometers increased their daily activity by 2,183 steps.

“Just over 2,100 steps might not sound like that much, but it equates to a 27 percent increase in physical activity — which is really astounding,” said Bravata in a Nov. 20 School of Medicine news release.

Bravata also observed that most participants experienced a drop in systolic blood pressure and a slightly lower body mass index (BMI) after using a pedometer for the duration of the study.

Though the study did not formally analyze why a pedometer might motivate people to increase their daily activity levels, Crystal Smith-Spangler, one of the members of the research team at Stanford, had a few suggestions.

“Persons who are successful in using pedometers to motivate them to exercise have commented that it is like ‘having a buddy’ watch them and make sure they achieve their personal physical activity goals,” she said. “Using a pedometer daily provides instant feedback on whether they achieve their goal and allows them to alter their behavior by going on a longer walk, or walking instead of driving, if they fall short of their goal.”

Though the study did not include any Stanford students or faculty in its research, free pedometers were distributed to all incoming freshmen as part of the Freshman Fitness Challenge in September in an effort to establish healthy activity habits in the Class of 2011.

Several Stanford faculty members also use pedometers, including Haas Center Interim Director Jackie Schmidt-Posner. She found that using a pedometer provided her with valuable feedback about her levels of activity throughout the week.

“When I was home on the weekend I ended up easily walking 10,000 steps just in the course of daily life — shopping, carrying laundry up and down stairs, doing things in the yard, walking the dog,” she said. “But at work, where I perceive myself as being up and out of my office a lot, I could find at the end of the day that I had only walked 2,400 steps.

“It made me think about how I could add more activity to my day by taking the stairs instead of an elevator, walking to a farther away place on campus for lunch, etc.,” she added.

Bravata’s study was supported by a grant from the National Institute on Aging through the Stanford Center on the Demography and Economics of Health and Aging.