Table 1

Demographic and Clinical Characteristics of the Study Participants Across Age-, Sex-, Ethnicity-Adjusted Baseline CRF Tertiles

Low Fit
Tertile 1
(n = 1,124)
Moderate Fit
Tertile 2
(n = 1,174)
High Fit
Tertile 3
(n = 1,135)
p Trend
Age, yrs25.1 ± 3.625.0 ± 3.725.1 ± 3.60.70
Females, %57.256.656.20.63
Blacks, %47.046.346.60.86
BMI, kg/m227.1 ± 6.323.8 ± 3.722.6 ± 2.8<0.0001
Systolic BP, mm Hg111 ± 11110 ± 10109 ± 10<0.0001
Diabetes mellitus, %1.40.50.10.0001
Current smoking, %34.226.121.0<0.0001
Education level less than high school, %71.163.854.9<0.0001
Physical activity levels (total intensity score)289.7 ± 247.5335. 8 ± 277.5391.6 ± 291.2<0.0001
Treadmill time, s443.7 ± 153.0593.7 ± 127.4721.7 ± 141.9<0.0001

Values are mean ± SD or %.

BMI = body mass index; BP = blood pressure; CRF = cardiorespiratory fitness.

  • CRF tertiles derived from baseline maximal treadmill time and adjusted for age, sex, and ethnicity.