Fitness for anti-aging. American College of Sports Medicine website. Available at: http://www.acsm.org/public-information/articles/2012/01/10/fitness-for-anti-aging. Updated January 10, 2012. Accessed February 10, 2016.
Physical activity guidelines: Older adults. Department of Health and Human Services website. Available at: http://www.health.gov/paguidelines/guidelines/default.aspx. Updated February 10, 2016. Accessed February 10, 2016.
Sample Exercises—flexibility. National Institute on Aging website. Available at http://www.nia.nih.gov/health/publication/exercise-physical-activity-your-everyday-guide-national-institute-aging/sample-2. Updated January 21, 2016. Accessed February 10, 2016.