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Article Excerpt
Regular physical activity (PA) improves mental health and reduces the risk of a number of adverse health outcomes, including cardiovascular disease mortality, hypertension, colon cancer, and diabetes mellitus (U.S. Department of Health and Human Services, 1996). Recent PA recommendations state that, in addition to strength and flexibility exercises, adults and older adults should participate in moderate PA for a minimum of 30 min, 5 days each week or vigorous-intensity aerobic PA for a minimum of 20 min, 3 days each week to achieve health benefits (Haskell et al., 2007; Nelson et al., 2007). The PA requirement can also be met through a combination of moderate- and vigorous-intensity activity.
Many studies with different strategies have been conducted to increase the level of PA for people of all ages. One of many strategies applied in intervention studies is the use of pedometers as a motivational tool. Pedometers are simple and inexpensive body-worn motion sensors that researchers and practitioners use to assess and motivate PA behaviors (Tudor-Locke & Bassett, 2004).
The Japanese developed the first electronic pedometer, called a "manpo-kei," meaning "10,000 steps meter" (Hatano, 1993). The goal of 10,000 steps/day gained popularity with the media and in practice and can be traced to Japanese walking clubs and a business slogan that was used more than 30 years ago. Taking 10,000 steps/day appears to be a reasonable goal of daily activity for healthy adults, and studies have documented the health benefits of attaining similar levels (Tudor-Locke & Bassett, 2004; Tudor-Locke, Hatano, Pangrazi, & Kang, 2008). In addition, Le Masurier, Sidman, and Corbin (2003) found that individuals who accumulate 10,000 steps/day are more likely to meet the PA guidelines by engaging in the amount of activity promoted by the Centers for Disease Control and Prevention, and the American College of Sports Medicine (Pate et al., 1995), and the U.S. Surgeon General (U.S. Department of Health and Human Services, 1996).
Pedometers have been recommended for use in PA interventions to motivate individuals to increase their ambulatory PA (DuVall et al., 2004; Tudor-Locke, 2001). Pedometers provide instant feedback to individuals using goal-setting principles (e.g., 10,000 steps/day goal). Most of the pedometer-based intervention studies report an increase in PA by the intervention group, but the magnitude of this increase and the effect of other variables (e.g., age and sex of participants, intervention length) are not known. A meta-analysis of those intervention studies can provide more information about the magnitude of change and the effect of those variables. Thus, the purpose of our study was twofold. The first goal was to use meta-analysis to determine the effectiveness of interventions using pedometer as a motivational tool. The second goal was to determine whether age (i.e., children, adults, older adults, and a combination of age groups) and sex of participants (i.e., male, female, or both), intervention length (i.e., number of intervention weeks), and intervention strategy (i.e., 10,000 steps/day goal, log, individual goal, and others) influence the effect of interventions.
Method
Data Sources
We identified studies by searching online databases--Medline, Pubmed, Sportdiscus, Google Scholar, AAHPERD National Convention and Exposition database, and Proquest--using the key words "pedometer" and "intervention." We used the reference lists of the studies to crosscheck and extend our search, which covered theses, dissertations, and published articles between January 2000 and August 2007.
Study Selection
The studies we selected met the following criteria: (a) at least one participant group used pedometers daily; (b) pedometers were used as a motivational tool during the intervention; (c) step counts were assessed pre- and postintervention; and (d) the intervention period lasted at least 4 weeks.
Because pedometers are measurement devices and motivational tools, it is difficult to untangle the psychological mechanisms of behavioral reactivity, serf-monitoring, and feedback (from steps or that augmented by researchers), as well as the influences of different step goals on behavior. To isolate the effects of behavioral reactivity, some researchers have sealed the pedometers to restrict self-monitoring. However, these studies are not typically identified as intervention designs and were, therefore, not included in our analysis. Regardless, behavioral reactivity to pedometer self-monitoring is usually negligible (Behrens & Dinger, 2007), and is likely to affect the intervention and control groups to a similar degree.
Data Extraction
After studies were identified, we independently coded the studies, and disagreements were resolved by consensus. The following variables were extracted: (a) age and sex of participants, intervention length; (b) intervention strategy; (c) pre- and postintervention step counts; and (d) statistical data. When there was insufficient information to compute an effect size (ES), we contacted a corresponding author from each study to obtain means and/or standard deviations to enable computation of an ES. At least one ES was calculated; additional ESs were calculated based on the moderating variables (i.e., sex, intervention length), if available....
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