Echocardiographic dimensions, anthropometric data and maximal oxygen uptake (VO2max) were studied in 26 healthy sedentary male controls (mean age, 22.0 yrs) and 15 male endurance athletes (mean age, 20.3 yrs). Athletes displayed significantly greater mean values for left ventricular internal dimension at end-diastole (LVIDd), end-diastolic volume (LVEDV) and left ventricular mass (LVM). Statistically significant positive correlations were observed within the sedentary control group between left ventricular end-diastolic dimensions (LVIDd, mm and/or LVEDV, cm3) and body height (cm), body weight (kg), chest circumference (cm) and body surface area (m2). Left ventricular mass (LVM, g) correlated significantly with lean body mass (kg). Ectomorphic somatotype rating (Ecto) correlated negatively with LVEDV and LVM. Finally, VO2max (l/min) correlated significantly with LVIDd, LVEDV and LVM. Multiple linear regression analysis indicated that the degree of endomorphy (Endo), LVIDd (mm/m2) and chest circumference accounted for 89% of the variance in VO2max (ml/kg/min) within the athlete group. Endo, Ecto and LVIDd (mm/m2) accounted for 86% of the variance in VO2max (ml/kg/min) in the control group. This study supports the hypothesis that maximal aerobic power can be predicted from cardiac and anthropometric measurements.