title: Longitudinal change in physical activity and disability in adults.
abstract: OBJECTIVE
  To prospectively examine whether physical activity or change in physical activity increases or decreases the risk of disability later in life.
  
  
  METHODS
  Tobit regression models were used to examine the effect of physical activity at baseline and change from  baseline on disability 10 and 20 years later in 6913 adults.
  
  
  RESULTS
  Increasing recreational physical activity was associated with reduced risk of disability whereas reducing recreational physical activity increased the risk of disability after 10 years.
  
  
  CONCLUSIONS
  The analyses  reveal a protective effect of sustained physical activity on disability among adults.
authors.affiliation: Department of Kinesiology, Health and Sport Studies, Wayne State University, Detroit, MI, USA. r.gretebeck@wayne.edu
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Gretebeck
authors.forename: Kenneth F
authors.initials: KF
authors.lastname: Ferraro
authors.forename: David R
authors.initials: DR
authors.lastname: Black
authors.forename: Kimberlee
authors.initials: K
authors.lastname: Holland
authors.forename: Kimberlee A
authors.initials: KA
authors.lastname: Gretebeck
mesh_terms: D000328:Adult; D000368:Aged; D006233:Persons with Disabilities; D015444:Exercise; D005260:Female; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness; D011446:Prospective Studies; D014481:United States