title: Physical activity, cardiorespiratory fitness, and the primary components of blood viscosity.
abstract: OBJECTIVE
  The relationship of both self-reported leisure time physical activity (LTPA) and predicted maximum oxygen consumption (VO2max) with plasma viscosity and hematocrit (Hct) concentration was examined within a cross-sectional sample of employed middle-aged men.
  
  
  METHODS
  Analyses were performed on a subsample of nonsmoking men who completed a preventive medical assessment between 1992-1996.
  
  
  RESULTS
  Among nonsmokers the mean age-adjusted levels of plasma viscosity (N = 590) and Hct concentration (N = 632) were significantly lower with higher Physical Activity Index (PAI) categories (P = 0.001 and P = 0.01, respectively). Following adjustment for conventional IHD risk factors and blood leukocyte count, a significant inverse relationship remained for Hct (P = 0.044) but not plasma viscosity. Mean age-adjusted plasma viscosity and Hct concentration also showed a significant decrease with higher quartiles of predicted VO2max (mL x kg(-1) x min(-1))(P = < 0.00005 and P = 0.0004, respectively). Following adjustment for all confounding variables mean plasma viscosity and Hct concentration remained significantly lower with higher quartiles of predicted VO2max (mL x kg(-1) x min(-1))(P = < 0.00005 and P = 0.047).
  
  
  CONCLUSIONS
  These data confirm the inverse relationship between LTPA and/or predicted VO2max with plasma viscosity and Hct concentration within nonsmoking middle-aged men of high socioeconomic status.
authors.affiliation: School of Leisure and Sports Studies, Leeds Metropolitan University, Beckett Park Campus, United Kingdom. scarrol@lmu.ac.uk
authors.forename: S
authors.initials: S
authors.lastname: Carroll
authors.forename: C B
authors.initials: CB
authors.lastname: Cooke
authors.forename: R J
authors.initials: RJ
authors.lastname: Butterly
mesh_terms: D000328:Adult; D001809:Blood Viscosity / Q000502:physiology*; D003430:Cross-Sectional Studies; D015444:Exercise; D006400:Hematocrit; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000209:etiology; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance