Physical Activity and Health Equity: Evolving the Science:

The case for a fundamental role of physical activity in the health and well-being of children and adults is strong and has led to the creation of national physical activity guidelines based on a systematic and thorough review of the science. Potential benefits of physical activity for preventing unwanted weight gain and facilitating both weight loss and maintenance are of particular interest as we face challenges posed by the obesity epidemic. Benefits extend beyond effects on weight to direct effects in the prevention of type 2 diabetes, heart disease, hypertension, stroke, breast and colon cancer, osteoporosis, and anxiety and depression. Increased physical activity and decreased physical inactivity or sedentary behavior (e.g., television viewing, computer use) are two different but related targets for intervention. Physical activity and sedentary behavior are particularly important as targets for reducing health disparities and achieving health equity. Obesity and most other health outcomes for which physical activity is beneficial are more prevalent in communities of color. Physical activity levels in communities of color are generally lower than those in the population at large, and disparities may be increasing. Moreover, from an environmental perspective, the prospects for improving activity levels in communities of color are themselves inequitable. This issue of the American Journal of Health Promotion includes two detailed systematic reviews of physical activity interventions in communities of color, covering approximately 20 years, through 2006. One focuses on African-Americans and the other on American Indians and Alaska natives. The authors of both reviews identify characteristics of effective physical activity interventions in adults and youth in the respective populations. In the process, they also assess the status and salience of the relevant science with respect to the potential for impact. The reviews were independent but addressed similar issues: the amount and nature of available evidence; characteristics of interventions, such as cultural adaptations or appropriateness, effectiveness, and sustainability; and potential ‘‘best practices.’’ The two reviews were developed initially as part of an ‘‘Equal Rights to Health’’ initiative sponsored by the Robert Wood Johnson Foundation together with the California Endowment, Morehouse School of Medicine, and Casey Family Programs. The purpose of that initiative was to learn more about combating obesity among low-income racial and ethnic minority children, including program evaluation and research funding needs. The rationale was that a review of work already done and evaluated was essential as a platform from which to break new ground in this arena, avoid pitfalls and unfertile areas already identified by others, and avoid ‘‘reinventing the wheel,’’ by identifying best practices based on current knowledge. The leaders of this initiative were acutely aware of the urgency of making inroads on obesity and other health problems related to physical inactivity but were also aware that the long-term effort needed was still in a relatively embryonic form. It was therefore considered of critical importance to challenge the available evidence base with probes for insights about how to proceed and to sustain effective approaches. The relative paucity and uneven quality of studies available were understood at the outset. Authors were asked to use systematic approaches that would be credible within the context of current standards for evidence-based practice. Therefore, while recognizing the sparse and eclectic nature of the relevant literature, the authors aimed to undertake systematic reviews of high quality and rigor, especially given the dearth of goodquality reviews of physical activity research conducted among minority populations. Within the overall effort to address the obesity epidemic, high-risk and sociopolitically marginalized segments of the population will require robust interventions with the highest possible likelihood of succeeding if improved health and health equity are to be achieved. Systematic approaches to identifying and extracting information from the relevant studies or reports were also deemed essential because of the expected heterogeneity and inadequacy of the literature. What better way to identify the research needs and gaps? Below we comment on methodologic considerations and findings key in these reviews, emphasizing common threads and implications for future research directions. We conclude with a note on relevant studies published since 2006 with respect to how research in this domain is evolving.