Book excerpt: In the past, research involving the relationship between physical activity and health has appeared in many diverse journals, with no one publication being devoted to that relationship. The Journal of Physical Activity and Health (JPAH) answers the need for a single publication with a focus solely on physical activity and health. JPAH publishes original research and review papers examining how physical activity influences all aspects of health, studying physical activity as an exposure as well as an outcome. It also invites papers that examine the behavioral, community, and environmental interventions that may affect physical activity on an individual and population basis. Recent issues of JPAH have addressed topics such as measurement of physical activity, surveillance of physical activity, meeting guidelines for physical activity in working populations, and physical activity intervention in older adults with chronic diseases. Research has been published from many international authors. Articles on physical activity patterns and the environment are planned for later this year. Also available is the online format of JPAH that offers the same authoritative content contained in the print edition, but with the additional advantages of electronically formatted material including the potential to search journals in seconds, access to five years of back issues, and the ability to examine the online version weeks before the print version arrives. Online subscribers are also sent each issue's table of contents by e-mail to announce that a new issue has been published.