title: The impact of race and higher socioeconomic status on cardiorespiratory fitness.
abstract: OBJECTIVE
  Previous studies suggest that African Americans (AA) have lower levels of cardiorespiratory fitness (CRF) than their Caucasian (C) counterparts. However, the association between CRF and race/ethnicity in the context of higher socioeconomic status (SES) has not been explored.
  
  
  METHODS
  We evaluated 589 AA (309 men and 203 women) and 33,015 C (19,399 men and 8753 women) enrolled in the Cooper Center Longitudinal Study. Education years and access to a preventive health care examination were used as a proxy for higher SES. Data were collected from a questionnaire, maximal treadmill exercise stress test, and other clinical measures. The outcome variable was CRF, which was stratified into low fit (quintile 1 of CRF) and fit (quintiles 2-5). Multivariable regression was used to compare adjusted mean CRF between groups. P values were adjusted for unbalanced sample size and unequal variance between groups.
  
  
  RESULTS
  The mean education years were similar for AA and C men at 16 yr; however, AA women had more years of education than C (15.8 vs 15.2 yr, P = 0.0062). AA men and women had a significantly higher prevalence of being unfit compared with their C counterparts (men 26.7% vs 12.6%, P < 0.0001; women 21.3% vs 8.4%, P < 0.0001). The adjusted mean estimated maximal METs were 10.9 vs 11.7 and 8.8 vs 9.8 for AA and C men and women, respectively. Fully adjusted odds ratios revealed that AA men had more than twice the risk of being unfit compared with C men. A trend persisted for AA women to have a lower MET value than their counterparts.
  
  
  CONCLUSIONS
  Despite comparable higher SES, lower CRF existed among AA men versus C men. These results suggest that CRF may not be mediated strictly by environmental factors related to SES.
authors.affiliation: 1The Cooper Institute, Dallas, TX; 2Department of Psychology, Howard University, Washington, DC; 3Prevention Research Center, Department of Medicine, Stanford University, Palo Alto, CA; and 4Cardiovascular Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD.
authors.forename: Erica N
authors.initials: EN
authors.lastname: Howard
authors.forename: Georita M
authors.initials: GM
authors.lastname: Frierson
authors.forename: Benjamin L
authors.initials: BL
authors.lastname: Willis
authors.forename: William L
authors.initials: WL
authors.lastname: Haskell
authors.forename: Tiffany M
authors.initials: TM
authors.lastname: Powell-Wiley
authors.forename: Laura F
authors.initials: LF
authors.lastname: Defina
mesh_terms: D000328:Adult; D001741:Black or African American; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness / Q000502:physiology*; D012923:Social Class; D012959:Socioeconomic Factors; D013781:Texas; D044465:White People