Cardiovascular fitness among US adults: NHANES 1999-2000 and 2001-2002

Purpose: To present information on cardiovascular fitness (estimated maximal oxygen uptake [VO(2)max] and cardiovascular fitness levels based on sex- and age-specific cut-points of estimated VO2max among U.S. adults. Methods: Analysis of data on 1978 adults (20-49 yr) who had completed a submaximal exercise test, from the National Health and Nutrition Examination Survey (1999-2000 and 2001-2002), a cross-sectional health survey of a nationally representative sample of the noninstitutionalized U.S. population Results: Estimated VO2max was significantly lower (P < 0.01) in non-Hispanic black ([mean +/- standard error] 38.2 +/- 0.7 mL(.)min(-1)center dot-kg(-1)) than Mexican-American and non-Hispanic white adults (41.5 +/- 0.6 and 40.6 +/- 0.4 mL(.)min(-1.)kg(-1), respectively). Estimated VO2max was also significantly lower (P < 0.001) in non-Hispanic black females (33.1 +/- 0.6 mL(.)min(-1.)kg(-1)) than in Mexican-American and non-Hispanic white females (37.0 +/- 0.7 and 36.4 +/- 0.4 mL(.)min(-1.)kg(-1), respectively). The proportion of low, moderate, and high cardiovascular fitness differed (P < 0.001) among race and race-sex groups. This difference was most striking among females, where 30.9% [95% confidence interval = 23.6-38.2%] of non-Hispanic black women had a low cardiovascular fitness level, compared with only 13.5% [10.0-17.0%] of non-Hispanic white and 18.9% [14.0-23.8%] of Mexican-American women. Conclusions: Adults of non-Hispanic black race have lower cardiovascular fitness than other major race groups in the United States. Nearly one third of non-Hispanic black women had a low cardiovascular fitness level, suggesting that this group in particular may be at increased health risk due to low cardiovascular fitness.