On 55 healthy test persons with normal weight and 76 healthy middle-aged obese test persons the measurement of systolic time intervals was performed standing and lying. In 39 obese patients and 55 test persons with normal weight a load ergometry was carried out. No significant difference between persons with normal weight and extreme overweight was recognized with regard to the index of tension. However, there were clear differences between persons with normal and overweight as to the time of tension and left-ventricular ejection time lying and standing, independent of the behaviour of blood pressure. In persons with overweight a significantly lower cardiac output was found. The index of tension of obese persons with a degree of efficacy below 75 Watt was on an average 1.04. Only half of the persons with overweight reached a degree of efficacy of 100 Watt. In 32 obese persons with a degree of efficacy of more than 75 Watt the regulation of frequency and blood pressure did not differ from that of persons with normal weight.