The number and scope of established health-related benefits from physical activity continue to expand. Notable recent additions include improved weight status and bone health in children 3–5 years of age, prevention of excessive weight gain among adults, reduced risk of dementia, and improved cognition and a variety of other brain-health benefits. Greater flexibility in receiving health benefits is also apparent. No threshold of moderate to vigorous physical activity (MVPA) must be exceeded for benefits to accrue; small increments by individuals performing little to no MVPA produce larger reductions in risk than similarly sized increments in individuals already performing greater amounts of MVPA, bouts of MVPA <10 min in duration contribute to the accumulation of MVPA, and light-intensity physical activity can benefit individuals currently doing little or no MVPA. MVPA is indirectly related to the adverse effects of sedentary behavior. The definition of physical activity continues to be debated.
Kenneth E. Powell and Steven N. Blair
Gregory W. Heath, Ross C. Brownson, Judy Kruger, Rebecca Miles, Kenneth E. Powell, Leigh T. Ramsey, and the Task Force on Community Preventive Services
Although a number of environmental and policy interventions to promote physical activity are being widely used, there is sparse systematic information on the most effective approaches to guide population-wide interventions.
We reviewed studies that addressed the following environmental and policy strategies to promote physical activity: community-scale urban design and land use policies and practices to increase physical activity; street-scale urban design and land use policies to increase physical activity; and transportation and travel policies and practices. These systematic reviews were based on the methods of the independent Task Force on Community Preventive Services. Exposure variables were classified according to the types of infrastructures/policies present in each study. Measures of physical activity behavior were used to assess effectiveness.
Two interventions were effective in promoting physical activity (community-scale and street-scale urban design and land use policies and practices). Additional information about applicability, other effects, and barriers to implementation are provided for these interventions. Evidence is insufficient to assess transportation policy and practices to promote physical activity.
Because community- and street-scale urban design and land-use policies and practices met the Community Guide criteria for being effective physical activity interventions, implementing these policies and practices at the community-level should be a priority of public health practitioners and community decision makers.
Kenneth E. Powell, Abby C. King, David M. Buchner, Wayne W. Campbell, Loretta DiPietro, Kirk I. Erickson, Charles H. Hillman, John M. Jakicic, Kathleen F. Janz, Peter T. Katzmarzyk, William E. Kraus, Richard F. Macko, David X. Marquez, Anne McTiernan, Russell R. Pate, Linda S. Pescatello, and Melicia C. Whitt-Glover
Background: The 2018 Physical Activity Guidelines Advisory Committee Scientific Report provides the evidence base for the Physical Activity Guidelines for Americans, 2nd Edition. Methods: The 2018 Physical Activity Guidelines Advisory Committee addressed 38 questions and 104 subquestions selected for their public health relevance, potential to inform public policies and programs, maturity of the relevant science, and applicability to the general US population. Rigorous systematic literature searches and literature reviews were performed using standardized methods. Results: Newly described benefits of physical activity include reduced risk of excessive weight gain in children and adults, incidence of 6 types of cancer, and fall-related injuries in older people. Physical activity is associated with enhanced cognitive function and mental health across the life span, plus improved mental health and physical function. There is no threshold that must be exceeded before benefits begin to accrue; the accrual is most rapid for the least active individuals. Sedentary time is directly associated with elevated risk of all-cause and cardiovascular mortality, incident cardiovascular disease and type 2 diabetes, and selected cancer sites. A wide range of intervention strategies have demonstrated success in increasing physical activity. Conclusion: The 2018 Physical Activity Guidelines Advisory Committee Scientific Report provides compelling new evidence to inform physical activity recommendations, practice, and policy.