The Joint Associations of Sedentary Time and Physical Activity With Mobility Disability in Older People: The NIH-AARP Diet and Health Study

J Gerontol A Biol Sci Med Sci. 2018 Mar 14;73(4):532-538. doi: 10.1093/gerona/glx122.


Background: The purpose of this study was to determine the joint associations of sedentary time and physical activity with mobility disability in older age.

Methods: We analyzed prospective data from 134,269 participants in the National Institutes of Health (NIH)-American Association of Retired Persons (NIH-AARP) Diet and Health Study between 1995-1996 and 2004-2005. Total sitting time (h/d), TV viewing time (h/d) and light- and moderate-to-vigorous-intensity physical activity (h/wk) were self-reported at baseline, and mobility disability at follow-up was defined as being "unable to walk" or having an "easy usual walking pace (<2 mph)." Multivariable logistic regression determined the independent and joint associations of sedentary time and total physical activity with the odds of disability.

Results: Among the most active participants (>7 h/wk), sitting <6 h/d was not related to excess disability at follow-up, and those in the most active group reporting the highest level of sitting time (≥7 h/d) still had a significantly lower odds (odds ratios = 1.11; 95% confidence interval = 1.02, 1.20) compared with those reporting the lowest level of sitting (<3 h/d) in the least active group (≤3 h/wk; odds ratios = 2.07; 95% confidence interval = 1.92, 2.23). Greater TV time was significantly related to increased disability within all levels of physical activity.

Conclusions: Reduction of sedentary time, combined with increased physical activity may be necessary to maintain function in older age.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Aged
  • Disability Evaluation*
  • Exercise*
  • Female
  • Health Surveys
  • Humans
  • Male
  • Middle Aged
  • Mobility Limitation*
  • Prospective Studies
  • Sedentary Behavior*
  • United States