title: Association of physical workload and leisure time physical activity with incident mobility limitations: a follow-up study.
abstract: OBJECTIVE
  To examine individual as well as joint associations of physical workload and leisure time physical activity with incident mobility limitations in initially well-functioning middle-aged workers.
  
  
  METHODS
  This study is based on 6-year follow-up data of the Danish Longitudinal Study on Work, Unemployment and Health. Physical workload was reported at baseline and categorised as light, moderate or heavy. Baseline leisure time physical activity level was categorised as sedentary or active following the current recommendations on physical activity. Incidence of mobility limitations in climbing stairs and running among initially well-functioning workers (n=3202 and n=2821, respectively) was assessed during follow-up.
  
  
  RESULTS
  Higher workload increased whereas active leisure time decreased the risk of developing mobility limitations. The incidence of limitations increased progressively with higher workload regardless of level of leisure time physical activity, although the risks tended to be higher among those with sedentary leisure time compared with their active counterparts. All in all, the risk for onset of mobility limitations was highest among those with heavy workload combined with sedentary leisure time and lowest among those with light workload combined with active leisure time.
  
  
  CONCLUSIONS
  Although leisure time physical activity prevents development of mobility decline, high workload seems to accelerate the progression of mobility limitations among both those with active and sedentary leisure time. Therefore, efforts should be made to recommend people to engage in physical activity regardless of their physical workload.
authors.affiliation: Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Mänty
authors.affiliation: Department of Occupational Medicine, Køge Hospital, Køge, Denmark The Research Unit for General Practice and Section of General Practice, Department of Public Health, University of Copenhagen, Copenhagen, Denmark National Research Centre for the Working Environment, Copenhagen, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Møller
authors.affiliation: Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Nilsson
authors.affiliation: Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
authors.forename: R
authors.initials: R
authors.lastname: Lund
authors.affiliation: Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
authors.forename: U
authors.initials: U
authors.lastname: Christensen
authors.affiliation: Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark The Danish Aging Research Centre, Universities of Odense, Aarhus and Copenhagen, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Avlund
mesh_terms: D000328:Adult; D003718:Denmark; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007899:Leisure Activities; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D009068:Movement; D009790:Occupations; D012307:Risk Factors; D057185:Sedentary Behavior; D013314:Stress, Mechanical; D014937:Work; D016526:Workload