title: Physical activity, sedentary time and physical capability in early old age: British birth cohort study.
abstract: OBJECTIVE
  To investigate the associations of time spent sedentary, in moderate-to-vigorous-intensity physical activity (MVPA) and physical activity energy expenditure (PAEE) with physical capability measures at age 60-64 years.
  
  
  METHODS
  Time spent sedentary and in MVPA and, PAEE were assessed using individually calibrated combined heart rate and movement sensing among 1727 participants from the MRC National Survey of Health and Development in England, Scotland and Wales as part of a detailed clinical assessment undertaken in 2006-2010. Multivariable linear regression models were used to examine the cross-sectional associations between standardised measures of each of these behavioural variables with grip strength, chair rise and timed up-&-go (TUG) speed and standing balance time.
  
  
  RESULTS
  Greater time spent in MVPA was associated with higher levels of physical capability; adjusted mean differences in each capability measure per 1 standard deviation increase in MVPA time were: grip strength (0.477 kg, 95% confidence interval (CI): 0.015 to 0.939), chair rise speed (0.429 stands/min, 95% CI: 0.093 to 0.764), standing balance time (0.028 s, 95% CI: 0.003 to 0.053) and TUG speed (0.019 m/s, 95% CI: 0.011 to 0.026). In contrast, time spent sedentary was associated with lower grip strength (-0.540 kg, 95% CI: -1.013 to -0.066) and TUG speed (-0.011 m/s, 95% CI: -0.019 to -0.004). Associations for PAEE were similar to those for MVPA.
  
  
  CONCLUSIONS
  Higher levels of MVPA and overall physical activity (PAEE) are associated with greater levels of physical capability whereas time spent sedentary is associated with lower levels of capability. Future intervention studies in older adults should focus on both the promotion of physical activity and reduction in time spent sedentary.
authors.affiliation: MRC Epidemiology Unit, University of Cambridge, Institute of Metabolic Science, Box 285, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, United Kingdom.
authors.forename: Andrew J M
authors.initials: AJ
authors.lastname: Cooper
authors.affiliation: MRC Epidemiology Unit, University of Cambridge, Institute of Metabolic Science, Box 285, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, United Kingdom.
authors.forename: Rebecca K
authors.initials: RK
authors.lastname: Simmons
authors.affiliation: MRC Unit for Lifelong Health & Ageing at UCL, 33 Bedford Place, London, WC1B 5JU, United Kingdom.
authors.forename: Diana
authors.initials: D
authors.lastname: Kuh
authors.affiliation: MRC Epidemiology Unit, University of Cambridge, Institute of Metabolic Science, Box 285, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, United Kingdom.
authors.forename: Soren
authors.initials: S
authors.lastname: Brage
authors.affiliation: MRC Unit for Lifelong Health & Ageing at UCL, 33 Bedford Place, London, WC1B 5JU, United Kingdom.
authors.forename: Rachel
authors.initials: R
authors.lastname: Cooper
mesh_terms: D003430:Cross-Sectional Studies; D004734:Energy Metabolism / Q000502:physiology; D004739:England; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D012606:Scotland; D057185:Sedentary Behavior; D014852:Wales