Assessing daily physical activity in older adults: unraveling the complexity of monitors, measures and methods.

Author(s)	Schrack JA, Cooper R, Koster A, Shiroma EJ, Murabito JM, Rejeski WJ, Ferrucci L, Harris TB
Journal / Source	http://biomedgerontology.oxfordjournals.org/content/71/8/1039.long
Date	March 2016