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Associate Professor

Jennifer Schrack, PhD '11, MS, uses data from wearable technology to elucidate novel, modifiable mechanisms of physical and cognitive decline with aging.

Contact Info

615 N. Wolfe Street, Room E7144

Research Interests

Aging; Movement; Physical Activity; Fatigability; Dementia
Experiences & Accomplishments
Johns Hopkins Bloomberg School of Public Health
University of Michigan
Dr. Schrack's primary area of research is the epidemiological assessment of phenotypic measures of aging, and their corresponding associations with health and longevity in older populations. Movement and health are intrinsically linked; by measuring factors such as gait speed, physical activity, fatigability, and falls, Dr. Schrack is working to elucidate novel, modifiable mechanisms of physical and cognitive decline with aging. Until recently, measures of human performance were limited to laboratory settings. However, the advent of wearable technology presents an unprecedented opportunity to better understand how quantities, patterns, and trends of daily movement predict physical and cognitive outcomes with aging. These technologically advanced monitors have the potential to ultimately transform clinical research and be widely used as preventative therapy tools.  Using advanced data collection and analytical methodology, Dr. Schrack is working to develop and validate new metrics of movement for older populations.  This work is crucial to understanding changes in physical and cognitive functioning with age that will inform future interventions aimed at curbing threats to healthy longevity including high fatigability, physical disability, and dementia.
Honors & Awards
2018 Golden Apple Award for Excellence in Teaching: Honors in Public Health 2017 Johns Hopkins University Catalyst Award 2014 - 2017 K01 Career Development Award, National Institute on Aging 2014 - 2015 Johns Hopkins Roybal Center Faculty Pilot Award 2013 - 2015 Johns Hopkins Center for AIDS Research Faculty Development Award
Select Publications
Selected publications
  • Wanigatunga AA, Di J, Zipunnikov V, Urbanek JK, Kuo P, Simonsick EM, Ferrucci L, Schrack JA. Association of Total Daily Physical Activity and Fragmented Physical Activity with Mortality in Older Adults. JAMA Netw Open. 2019 Oct 2;2(10):e1912352. PMID: 31577355
  • Schrack JA, Zipunnikov V, Goldsmith AJ, Crainiceanu CM, Simonsick EM, Ferrucci L.  Assessing the “Physical Cliff”: Detailed Quantification of Physical Activity and Aging. J Gerontol A Biol Sci Med Sci. 2014 Aug;69(8):973-9. PMID: 24336819.
  • Schrack JA, Cooper R, Koster A, Shiroma EJ, Murabito JM, Rejeski WJ, Ferrucci L, Harris TB. Assessing Daily Physical Activity in Older Adults: Unraveling the Complexity of Monitors, Measures, and Methods. J Gerontol A Biol Sci Med Sci. 2016 Aug;71(8): 1039-48. PMID: 26967472
  • Gresham G, Dy S, Zipunnikov V, Studenski SA, Simonsick EM, Ferrucci L, Schrack JA. Fatigability and Endurance Performance in Adults with a History of Cancer: Analyses from the Baltimore Longitudinal Study of Aging. Cancer. 2018 Mar 15;124(6):1279-1287. Doi: 10.1002/cncr.31238. PMID: 29419879
  • Martinez Amezcua P, Simonsick EM, Wanigatunga AA, Urbanek JK, Chiles Shaffer N, Ferrucci L, Schrack JA. The Association Between Adiposity and Perceived Fatigability in Mid-to-Late Life. Obesity (Silver Spring). 2019 May 25. PMID: 31127707
Changes in Sensorimotor Function as Predictors of Preclincial Alzheimer's Disease
MACS Energy Expenditure Study
Energy Expenditure, Physical Activity, and Alzheimer's Disease in the Baltimore Longitudinal Study of Aging (PI: Schrack)