Introduction: Lifestyle physical activity interventions have resulted in response to the public health problem of promoting regular amounts of physical activity to the majority of U.S. adults who remain inadequately or completely inactive. These lifestyle interventions allow a person to individualize his/her physical activity programs to include a wide variety of activities that are at least of moderate intensity and to accumulate bouts of these activities in a manner befitting his/her life circumstances. Methods: We reviewed the history of lifestyle physical activity interventions and defined lifestyle physical activity based on this review. We located 14 studies that met this definition. Results: Lifestyle physical activity interventions are effective at increasing and maintaining levels of physical activity that meet or exceed public health guidelines for physical activity in representative samples of previously sedentary adults and obese children. The majority of these interventions have been delivered by face-to-face contact in small groups, which limits their public health impact. However, a small number of studies demonstrate that these interventions can be delivered by mail and telephone, which may enhance their generalizability. Most of these studies utilized behavior change theories such as Social Cognitive Theory, the Transtheoretical Model, and Behavior Learning to shape the interventions. Lifestyle interventions aimed at modifying the environment, such as signs posted to increase stair climbing, also have been shown to be effective over the short term. Conclusion: The major issues concerning lifestyle physical activity interventions are: (I) testing their ability to be implemented on a large scale; (2) examining cost-effectiveness for different modes of delivery; and (3) researching the efficacy in populations such as the elderly, minorities, economically disadvantaged, and individuals with concurrent disease. More studies aimed at manipulating the environment to increase physical activity need to be tested over periods of one year or longer. It is possible that lifestyle interventions could be integrated and delivered by new technologies such as interactive computer-mediated programs, telephone, or computer web-based formats. All of these recommended approaches should utilize valid and reliable measures of physical activity and should examine the health effects, particularly on a longitudinal basis. Basic dose-response studies in controlled settings also are needed to help us understand the health effects of accumulated moderate intensity activity.
