Pedometers Increase Activity, Reduce BMI and BP

November 26, 2007 — A new review shows that use of a pedometer is associated with significant increases in physical activity and significant decreases in body mass index (BMI) and blood pressure (BP). Dr Dena Bravata (Stanford University, CA) and colleagues report their findings in the November 21, 2007 issue of the Journal of the American Medical Association[1].
Of note, Bravata told heartwire, they found that a daily goal with the pedometer was imperative for people to increase their physical activity. And a by-product of this increased activity were clinically relevant reductions in weight and blood pressure.
She said average weight loss was around three pounds. "Let's not discount that, let's put that into the context of very well-studied diet and exercise programs. With the exception of bariatric surgery, a lot of well-designed diet interventions don't result in much bigger reductions in weight. I think that the BP reduction and weight loss seen with pedometers is remarkable, given that these are small gizmos designed to increase physical activity, not reduce weight," she noted.
First published synthesis of the evidence
Bravata and colleagues explain that although there has been a surge in popularity for pedometers as a tool to motivate and monitor physical activity, there is a lack of detailed evidence of their effectiveness.
They looked at 26 studies with a total of 2767 participants (eight randomized controlled trials and 18 observation studies); 85% of participants were women, and the mean age was 49 years. The mean duration of pedometer use in the studies was 18 weeks.
They found that, on average, pedometer users significantly increased their physical activity by 2183 steps a day over baseline (p<0.0001), or by 26.9%.
An important predictor of increased physical activity was having a daily goal — such as the popular 10,000 steps per day recommendation or an individualized step goal (p=0.001). Pedometer users with a daily goal significantly increased their physical activity, whereas those who were not given a daily goal did not.
When data from all studies were combined, pedometer users significantly decreased their BMI by 0.38 (p=0.03), "which, in this cohort of patients, would have been enough to move them from the obese to the overweight category," Bravata told heartwire.
The reduction in systolic blood pressure observed, 3.8 mm Hg, "is also a remarkable finding," she added, "given that the participants were fairly normotensive at baseline. People have spent all kinds of money on very fancy quality-improvement strategies, and that's the kind of range that you get from some of those much bigger interventions," she said.
The researchers found no difference between types of pedometer used. Bravata said many of the studies used a Japanese device called the Yamax.
"Despite the abundance of lay literature on the use of pedometers, our study is the first published synthesis of the evidence," Bravata et al note. "Our results suggest that the use of these small, relatively inexpensive devices is associated with significant increases in physical activity and improvements in key health outcomes, at least in the short term."
However, "the extent to which these results are durable over the long term is unknown," they say, adding that large randomized controlled trials are needed to fully elucidate the potential benefits of pedometers.
The National Institute on Aging through the Stanford Center on the Demography and Economics of Health and Aging supported this study. Two of the study authors have received funding, one in part by the National Science Foundation. The remaining study authors have disclosed no relevant financial relationships.