There were two specific aims. The first was to test the hypothesis that controlled physical training (PT) reduced blood pressure, at rest and in reaction to forehead cold and exercise stressors, in 8-9 year olds who were high in both blood pressure and body fatness. Subjects were divided equally on gender and blood pressure and body fatness. Subjects were divided equally on gender and ethnicity (black/white). Both resting and reactive blood pressure were correlated with left ventricular mass and were predictive of future essential hypertension. The underlying hemodynamic regulators of blood pressure, cardiac output and the total peripheral resistance, were measured with impedance cardiography to explore hemodynamic mechanisms through which training had a favorable influence on blood pressure and left ventricular mass.