A small, inexpensive fitness gadget could be the key to getting people moving and burning calories.

A recent study has found that people who used pedometers, which clip to a waistband and count the number of steps walked per day, tended to walk an extra kilometre and a half a day. They also lowered their blood pressure and lost a few pounds along the way.

The study, published in the Journal of the American Medical Association, involved researchers at the Stanford University School of Medicine. They reviewed 26 studies that looked at the use of pedometers as a tool to motivate physical activity.

A total of 2,767 people participated in the studies; most were female, overweight and relatively inactive before they started their walking program. The mean study duration was 18 weeks.

Bravata and her team found that pedometer users in the randomized trials increased their physical activity by 2,491 steps per day more than participants who did not use pedometers.

In other studies, participants increased their walking by 2,183 steps per day after they started using a pedometer.

"Just over 2,100 steps might not sound that much, but it equates to a 27 per cent increase in physical activity - which is really astounding," said study co-author Dr. Dena Bravata, a senior research scientist in medicine.

"This goes a long way toward helping people meet the national guidelines for daily physical activity."

Most of the volunteers also lost a few pounds. Pedometer-users saw their body mass indexes (BMI) decrease by 0.4. They also saw their systolic blood pressure (the upper number of the two values) fall by 3.8 mm Hg.

Bravata said she considered this decrease quite significant, since a reduction of 2 mm Hg is associated with a 10 per cent reduction in stroke mortality.

The analysis found that the best way to increase physical activity was to keep a diary of the number of steps walked each day and set a goal.

"People don't always achieve it, but just having a goal seems to help them stay motivated and improve their physical activity," she noted.

Those who didn't keep a diary showed no significant increase in walking. Pedometer users who didn't have a step goal also failed to increase their physical activity.

James Hill, an obesity expert at University of Colorado, says he wasn't surprised by the findings. He co-founded America on the Move, a U.S. initiative encouraging people to add 2,000 steps a day to what they are already walking.

"It fits with everything we've seen; we can get pretty amazing increased physical activity by using pedometers," said Hill.

Bravata says she's now interested to know whether pedometer users can keep up their walking and wants to see more randomized, controlled studies on longer-term pedometer use.