Physical Activity Guidelines Advisory Committee Report, 2008 To the Secretary of Health and Human Services U.S. Department of Health and Human Services The findings of this report are those of the Physical Activity Guidelines Advisory Committee. They do not necessarily reflect the views of the Office of Disease Prevention and Health Promotion or the U.S. Department of Health and Human Services. Suggested citation: Physical Activity Guidelines Advisory Committee. Physical Activity Guidelines Advisory Committee Report, 2008. Washington, DC: U.S. Department of Health and Human Services, 2008. Physical Activity Guidelines Advisory Committee Report, 2008 Prepublication Copy Issued June 2008 DEPARTMENT OF HEALTH AND HUMAN SERVICES Office of the Secretary Assistant Secretary for Health Office of Public Health and Science Washington D.C. 20201 May 23, 2008 The Honorable Michael O. Leavitt Secretary of Health and Human Services 200 Independence Avenue, S.W. Washington, D.C. 20201 Dear Secretary Leavitt, On behalf of the entire 2008 Physical Activity Guidelines Advisory Committee, we are very pleased to submit the Physical Activity Guidelines Advisory Committee Report, 2008. You charged our committee to “…review existing scientific literature to identify where there is sufficient evidence to develop a comprehensive set of specific physical activity recommendations.” The Committee's report documents scientific background and rationale for the 2008 edition of the Physical Activity Guidelines for Americans. The Committee also identified areas where further scientific research is needed. The Committee’s review and deliberations clearly demonstrated that sedentary behavior confers substantial health risks throughout the lifespan. The health benefits of being habitually physically active appear to apply to all people regardless of age, sex, race/ethnicity, socioeconomic status, and to many people with physical or cognitive disabilities. The amount and intensity of physical activity needed to achieve many health benefits is well within the capacity of most Americans .and can be performed safely. This report provides the scientific basis for these conclusions and the development of federal physical activity guidelines. For the entire Committee, we want to thank you for the opportunity to support your Prevention Priority. Over the past twelve months, the Committee members and consultants worked exceptionally long and hard to conduct the extensive scientific review that made this report possible. Despite this task being added to their usual busy schedules, they met tight deadlines, provided insight and education to one another, and unselfishly worked to develop a consensus report. Thus, we wish to thank you for assembling a committee of outstanding professionals who are not only knowledgeable and highly productive but also most pleasant in character. U.S. Public Health Service It is important to emphasize that this report could not have been completed without the outstanding support of all the HHS staff who assisted us throughout the entire process. We are very grateful for their substantial assistance in developing an extensive electronic searchable literature database for use by the Committee and for their excellent logistical and management support in all aspects of the Committee's work. Special recognition goes to RADM Penelope Slade Royall and CAPT Richard Troiano of the Office of Disease Prevention and Health Promotion for their tireless dedication in the coordination, and ultimate completion, of this project. This report greatly benefits from the expert editing provided by Anne Brown Rodgers, who helped us present information that is useful and readable, and from the careful work of Reba Norman, who ensured the completeness and accuracy of the report’s extensive reference lists. Our review documents very strong scientific evidence that physically active people have higher levels of health-related fitness, a lower risk of developing a number of disabling medical conditions, and lower rates of various chronic diseases than people who are inactive. Given Americans' low rates of participation in physical activity and high prevalence of chronic diseases and associated disabilities, this report is particularly timely. It provides the necessary foundation for HHS to proceed to develop Physical Activity Guidelines for Americans, 2008 and related policy statements. Strong federal guidelines, policies, and programs regarding physical activity should be an essential component of any comprehensive disease prevention and health promotion strategy for Americans. Committee members are committed to the broad dissemination of this report and the ensuing guidelines. Please do not hesitate to contact us or any of the Committee members if we can be of further service. Sincerely, [Signed May 23, 2008] William L. Haskell, Ph.D Chair, 2008 Physical Activity Guidelines Advisory Committee Prevention Research Center, School of Medicine, Stanford University [Signed May 23, 2008] Miriam E. Nelson, Ph.D. Vice-Chair, 2008 Physical Activity Guidelines Advisory Committee John Hancock Center for Physical Activity and Nutrition Friedman School of Nutrition Science and Policy, Tufts University Contents Physical Activity Guidelines Advisory Committee Members ....................Front Matter-1 Part A: Executive Summary..............................................................................................A-1 The Physical Activity Guidelines Advisory Committee..............................................A-1 Report Contents..............................................................................................................A-2 Review of the Science on Physical Activity and Health ..............................................A-2 Research Recommendations........................................................................................A-10 Part B: Introduction...........................................................................................................B-1 Setting the Stage for Physical Activity Guidelines for Americans.............................B-1 The Physical Activity Guidelines Advisory Committee..............................................B-2 A Systematic Review of the Evidence on Physical Activity and Health....................B-3 Contents and Organization of the Physical Activity Guidelines Advisory Committee Report..........................................................................................................B-5 Part C: Key Terms .............................................................................................................C-1 Physical Activity and Exercise ......................................................................................C-1 Physical Fitness...............................................................................................................C-4 Health ..............................................................................................................................C-6 Study Design and Measurement ...................................................................................C-6 Publication Types ...........................................................................................................C-7 Reference List .................................................................................................................C-8 Part D: Background...........................................................................................................D-1 Introduction ....................................................................................................................D-1 Some Issues Regarding Dose Response ........................................................................D-1 Recent Trends in Physical Activity in the United States ............................................D-9 Development of Physical Activity Guidelines in the United States..........................D-17 Reference List ...............................................................................................................D-28 Part E: Integration and Summary of the Science ...........................................................E-1 Introduction ....................................................................................................................E-1 Summarizing the Evidence............................................................................................E-1 Integrating the Evidence: Questions and Answers About the Health Benefits of Physical Activity........................................................................................E-22 Reference List ...............................................................................................................E-35 Part F: Scientific Literature Search Methodology..........................................................F-1 Background.....................................................................................................................F-1 Conceptual Framework .................................................................................................F-1 Physical Activity Guidelines Advisory Committee Report v Contents Research Questions ........................................................................................................F-1 Operational Plan ............................................................................................................F-3 Literature Review...........................................................................................................F-4