Why Do Pedometers Work?

The results of two recent independent meta-analyses focused on pedometerbased programmes conclude that they work; that is, they are effective. Specifically, physical activity increases while blood pressure and weight decrease as a result of participating in a pedometer-based intervention. An improved understanding of the unique measurement and motivational properties of pedometers as behaviour-change tools will assist researchers and practitioners to maximize benefits. In an effort to begin to outline why pedometers work, for whom, and under what conditions, the purpose of this current opinion article is to explore the published literature (drawing heavily from those studies previously identified in published meta-analyses and our own work in this area) to identify factors related to using pedometers to increase physical activity. In particular it is important to: (i) gain a better understanding of the activitypromoting characteristics of pedometers; (ii) determine effective elements of pedometer-based programming; and (iii) identify participants who engage in, and benefit most from, such programming. Pedometers are most sensitive to walking behaviours, which is consistent with public health and clinical approaches to increasing physical activity. Specifically, they offer an affordable and accessible technology that is simplistic in output, low-literacy friendly, and immediately understandable to end-users. Support materials are becoming readily available for researchers and practitioners in terms of expected (normative or benchmark) values, patterns of change, indices to aid screening and interpretation, and measurement protocols. Pedometer-based programme theory is now being articulated and tested, and the critical elements necessary to shape a successful programme are becoming more clearly defined. More research is needed, however, to compare the effectiveness of self-selected individualized goals with tailored goals (based on a specified baseline characteristic, for example), standardized goals (e.g. percentage-based increments) and pre-set uniformly administered goals (i.e. a volume total of 10 000 steps/ day or an incremental total of 2000 extra steps/day for everyone). Since most studies of pedometer-based programmes have been of relatively short duration, it is unknown to what extent observed changes are sustainable or whether it is possible to continue to accrue benefits over long-term adherence. Peer delivery of treatment has the potential for enabling wider and less costly dissemination, although this has not been directly evaluated. In addition, the majority of pedometer-based programme participants to date have been women, suggesting that more research is needed onmen and how they react to this form of physical activity intervention. Increases in steps/day have been negatively correlated with baseline values, indicating that those with lower baseline steps/day stand to make the greatest relative incremental increases in physical activity behaviour. A clearly articulated programme theory is lacking in most interventions. A clearer understanding is needed of what programme features, including the nature of goal-setting, are necessary for optimal participant success. Additionally, we need a better profile of the participant who benefits most, and/or requires additional or alternative strategies to succeed in their personal behaviour-change attempts. Continued efforts to refine answers regarding what works well for whom under what conditions will foster evidencebased applications of pedometer-based programmes.