title: Mode-specific physical activity and leukocyte telomere length among U.S. adults: Implications of running on cellular aging.
abstract: BACKGROUND
  Previous research demonstrates that physical activity participation is associated with longer leukocyte telomere length, with shorter leukocyte telomere length being a hallmark characteristic of cellular aging. What remains under-investigated, however, is whether there is a mode-specific association of physical activity on leukocyte telomere length, which was this study's purpose.
  
  
  METHODS
  Data from the 1999-2002 National Health and Nutrition Examination Survey were used (N=6474 adults analyzed). Leukocyte telomere length was assessed using quantitative polymerase chain reaction. Physical activity was assessed via self-report, with participants classified as meeting physical activity guidelines (≥2000 metabolic equivalent of task-min-month) for 9 separate physical activities, including aerobics (unweighted percent meeting guidelines: 2.98%; n=193), basketball (2.0%; n=129), bicycling (3.71%; n=240), dance (2.30%; n=149), running (3.09%; n=200), stair climbing (1.33%, n=86), swimming (1.85%, n=120), walking (13.53%; n=876), and weight lifting (2.61%; n=169).
  
  
  RESULTS
  In a single multivariable linear regression model including the independent variables of age, gender, race-ethnicity, weight status, total cholesterol, C-reactive protein, total metabolic equivalent of task-min-month of physical activity and the 9 binary meeting physical activity guideline variables, the only mode of physical activity that was significantly associated with leukocyte telomere length was meeting physical activity guidelines from running (β=0.06; 95% CI: 0.01-0.11; P=0.03).
  
  
  CONCLUSIONS
  Running-specific physical activity was the only evaluated physical activity associated with leukocyte telomere length, which may provide one potential mechanism (i.e., leukocyte telomere length) through which running-based physical activity may help to prevent cardiovascular disease and premature mortality.
authors.affiliation: Department of Health, Exercise Science and Recreation Management, The University of Mississippi, University, MS 38677, USA. Electronic address: pdloprin@olemiss.edu.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Loprinzi
authors.affiliation: Department of Health, Exercise Science and Recreation Management, The University of Mississippi, University, MS 38677, USA.
authors.forename: Eveleen
authors.initials: E
authors.lastname: Sng
mesh_terms: D000328:Adult; D016922:Cellular Senescence / Q000235:genetics*; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000378:metabolism*; D016014:Linear Models; D008297:Male; D009749:Nutrition Surveys; D012420:Running / Q000502:physiology*; D016615:Telomere / Q000235:genetics*; D014481:United States
keywords: Cellular aging; Epidemiology; Running