1. Hogan H, Perez D, Bell WR. Who (Really) are the first baby boomers? In: Statistical meetings proceedings, social statistics section; Alexandria, VA. 2008.
2. U.S. Department of Health and Human Services. Physical activity guidelines advisory committee report. 2008. Available from: http://www.health.gov/paguidelines/report/pdf/CommitteeReport.pdf . Accessed: June 18, 2015.
3. U.S. Department of Health and Human Services. 2008 Physical activity guidelines for Americans. 2008. Available from: http://www.health.gov/paguidelines/pdf/paguide.pdf . Accessed: June 18, 2015.
4. U.S. Department of Health and Human Services. Behavioral Risk Factor Surveillance System [database on the Internet]. Centers for Disease Control and Prevention. 2013. Available from: http://www.cdc.gov/brfss/annual_data/annual_2013.html . Accessed: January 24, 2015.
5. U.S. Department of Health and Human Services. National Health and Nutrition Examination Survey, Accelerometer Data 2003–04 & 2005–06 [database on the Internet]. Available from: http://www.cdc.gov/nchs/nhanes/nhanes_questionnaires.htm . Accessed: January 25, 2015.