LEFT-VENTRICULAR WALL TENSION AND STRESS DURING EXERCISE IN ATHLETES AND SEDENTARY MEN

This investigation examines the hypothesis that hypertrophy attenuates wall stress during exercise, when left ventricular wall tension is hi ghest and most likely to contribute to hypertrophy. Upright bicycle ex ercise was performed by 17 endurance-trained male athletes and 15 sede ntary men. M-mode echocardiograms were obtained during submaximal exer cise at predetermined heart rates. At all levels of exercise, at a mat ched heart rate, wall tension was higher in athletes than in sedentary subjects. In both groups, wall tension increased with exercise, then plateaued. Wall stress did not differ significantly in athletes and se dentary subjects at rest and at heart rates of 110 and 150 beats/min, although a difference was observed at a heart rate of 130 beats/min. W all stress decreased in both athletes and sedentary subjects with exer cise. In conclusion, left ventricular hypertrophy caused wall stress i n athletes to be maintained at values similar to sedentary subjects du ring exercise as well as at rest.