A new US study found that using a pedometer, an inexpensive pocket sized device that counts the number of steps a person takes in a day, helped normally inactive people become more physically active, lose weight and reduce blood pressure.
The study, which is the first to review the literature on pedometers in a peer-reviewed journal, is published in the 21st November issue of the Journal of the American Medical Association (JAMA) and is the work of Dr Dena Bravata, a senior research scientist in medicine at the Stanford University School of Medicine in Stanford, California, and colleagues.
Commenting on the findings, lead author Bravata said:
“Much to my surprise, these little devices were shown to increase physical activity by just over 2,000 steps, or about 1 mile of walking per day.”
“This goes a long way toward helping people meet the national guidelines for daily physical activity,” she added.
According to the Centers for Disease Control and Prevention (CDC), two thirds of American adults are overweight or obese, and only 45 per cent get enough physical activity. The US Department of Health and Human Services recommends that adults should be physically active for at least 30 minutes a day, and organizations such as Shape Up America recommend that adults walk at least 10,000 steps each day.
Pedometers are being increasingly used as a way to count steps walked every day because they are cheap (many sell for 10 or 15 dollars each), easy to use and can be clipped to clothing or kept in a pocket. Some employers like Chevron Corp give them to their employees for free if they pledge to walk a certain number of steps a day.
Bravata wondered whether to recommend them to her patients who were not active enough, hence the motivation for the research.
“Improving health behaviors is the No. 1 thing I discuss during my patients’ routine visits, and I’m constantly seeking ways to get them to exercise more,” said Bravata.
The researchers reviewed over 2,000 published articles and selected 26 studies (18 observational and 8 randomized trials) that examined the use of the pedometer as a way to motivate people to become physically more active. A study was only included if it reported assessing pedometer use in adults, reported changes in steps per day, and included more than 5 participants.
Altogether the studies covered 2,767 participants, mostly female, their mean age was 49, they were overweight and relatively inactive before enrollment.
There was quite a varied range of walking programs among the studies, with an overall mean duration of 18 weeks. 23 of them included a target number of steps each day and a diary in which participants noted their daily activity; 17 of them included counselling and advice about physical activity, and 5 of them were carried out in the workplace.
The results showed that compared with non-pedometer users, the pedometer users in the randomized trials increasd their physical activity by 2,491 steps a day, while those in the observational studies increased by 2,183 steps a day over baseline.
Bravata said she was astounded by the results, because:
“Just over 2,100 steps might not sound that much, but it equates to a 27 percent increase in physical activity.”
The results also showed that pedometer users lost weight, their BMI went down by 0.4, which for a person who is 5 feet 6 inches tall (1.7 m) and initially weighs 195 pounds (88.5 kg) , this would be a loss of 2.5 pounds (1.1 kg). This decrease was linked to older age and having a step goal.
(Body Mass Index (BMI) is the ratio of a person’s weight in kilos to their height in metres squared.)
There were also improvements in blood pressure. Systolic blood pressure (the higher of the two numbers, when the heart contracts) fell by 3.8 mm Hg. This was considered significant because the baseline blood pressure of the participants was not high to begin with, although the decrease was more strongly linked with those whose blood pressure was higher.
Bravata pointed out that a reduction of just 2 mm Hg is linked to a 10 per cent reduced risk of death by stroke and 7 per cent reduced risk of death from cardiovascular causes.
Having a goal to aim for, such as 10,000 steps a day, appeared to be a key predictor of increased physical activity said the researchers. It was the key to motivation, even if they didn’t always achieve it, said Bravata.
The study concluded that:
“The results suggest that the use of a pedometer is associated with significant increases in physical activity and significant decreases in body mass index and blood pressure. Whether these changes are durable over the long term is undetermined.”
The researchers were aware of the study’s limitations. Only 15 per cent of the total participants were male, and the mean duration was only 18 weeks. However, they suggested there is enough evidence to make longer term, randomized controlled trials on the effectiveness of pedometers worthwhile.
In the meantime, Bravata said she hoped the results encourage doctors to recommend pedometers to their inactive patients.
Dr James Hill, an expert in obesity based at the University of Colorado, and co-founder of America on the Move, a national initiative that encourages people to increase physical activity by 2,000 steps a day, was not surprised by the results because, as he explained:
“It fits with everything we’ve seen; we can get pretty amazing increased physical activity by using pedometers.”
Hill said this study showed how simple changes can make a significant improvement to health.
“Nothing is simpler than getting a pedometer,” he said.
“Using Pedometers to Increase Physical Activity and Improve Health: A Systematic Review.”
Dena M. Bravata, Crystal Smith-Spangler, Vandana Sundaram, Allison L. Gienger, Nancy Lin, Robyn Lewis, Christopher D. Stave, Ingram Olkin, John R. Sirard.
JAMA. 2007;298(19):2296-2304.
Vol. 298 No. 19, November 21, 2007
Written by: Catharine Paddock