1. A report of the surgeon general;U.S. Department of Health and Human Services, Physical Activity and Health,1996
2. National blueprint for increasing physical activity for adults 50 and older;Robert Wood Johnson Foundation;J Aging Phys Act,2001
3. Physical activity guidelines advisory committee report 2008;Physical Activity Guidelines Advisory Committee,2008
4. State indicator report on physical activity 2014;Centers for Disease Control and Prevention,2014
5. Physical inactivity: the biggest public health problem of the 21st century;Blair;Br J Sports Med,2009