title: Precipitation and Physical Activity in Older Adults: The Moderating Role of Functional Mobility and Physical Activity Intentions.
abstract: OBJECTIVE
  Physical activity is a key health behavior that reduces disease risk, and yet most older adults are not very active. This study examined time-varying associations between physical activity and a recognized barrier, namely, precipitation. And it examined the moderating role of physical activity intentions and functional mobility on precipitation-physical activity associations.
  
  
  METHODS
  One hundred and twenty-six older adults (M age = 72 years; 64% women) from Metro Vancouver provided health and background information and wore triaxial accelerometers for up to 10 consecutive days. Daily weather information was collected from local weather stations.
  
  
  RESULTS
  Multilevel models corroborate previous research by showing that older adults engaged in less physical activity on days with increased precipitation across four indices: activity counts, step counts, minutes of moderate to vigorous physical activity (MVPA), and bout-corrected minutes of MVPA. Older adults with strong physical activity intentions engaged in more physical activity overall. Physical activity intentions also modified the association between time-varying precipitation and activity counts and step counts, whereas functional mobility moderated the negative association between precipitation and activity counts and minutes of MVPA.
  
  
  CONCLUSIONS
  Findings highlight the important role of time-varying influences on physical activity and how these associations are moderated by psychological and biological factors.
authors.affiliation: Department of Psychology.|Centre for Hip Health and Mobility, University of British Columbia, Vancouver, Canada.
authors.forename: Christiane A
authors.initials: CA
authors.lastname: Hoppmann
authors.affiliation: Department of Psychology.
authors.forename: Jessica Chak Man
authors.initials: JCM
authors.lastname: Lee
authors.affiliation: German Centre of Gerontology, Berlin, Germany.
authors.forename: Jochen P
authors.initials: JP
authors.lastname: Ziegelmann
authors.affiliation: Department of Psychology.
authors.forename: Peter
authors.initials: P
authors.lastname: Graf
authors.affiliation: Centre for Hip Health and Mobility, University of British Columbia, Vancouver, Canada.
authors.forename: Karim M
authors.initials: KM
authors.lastname: Khan
authors.affiliation: Centre for Hip Health and Mobility, University of British Columbia, Vancouver, Canada.|Department of Family Practice, University of British Columbia, Vancouver, Canada.
authors.forename: Maureen C
authors.initials: MC
authors.lastname: Ashe
mesh_terms: D061725:Accelerometry; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D001955:British Columbia; D015444:Exercise / Q000523:psychology*; D005260:Female; D006801:Humans; D033182:Intention; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D014887:Weather
keywords: Intention; Intra-individual variability; Physical activity; Weather