ONE-YEAR OF EXERCISE TRAINING DOES NOT ALTER RESTING LEFT-VENTRICULARSYSTOLIC OR DIASTOLIC FUNCTION

Few studies have examined the effect of prolonged exercise training on left ventricular diastolic function in previously sedentary subjects. We performed M-mode, 2-D, and Doppler echocardiography on 16 previous ly sedentary men before and after 1 yr of exercise training. Six men s erved as controls. Exercise subjects participated in four 1-h supervis ed sessions weekly at 60-80% of their measured maximal heart rate. Max imal oxygen uptake, maximal exercise cardiac output, and resting left ventricular systolic and diastolic function were determined before and after training. Maximal oxygen uptake and peak cardiac output increas ed 27.3% and 8.5% in the trainers (P < 0.001 for both) and 1.3% and 1. 0% in the controls. Left ventricular diastolic and systolic dimensions changed slightly in both groups. Maximal early inflow velocity decrea sed in both trainers (-9.9 +/- 14.0 cm . s(-1), mean +/- SD, P less th an or equal to 0.01) and controls (-7.2 +/- 10.2 cm . s(-1)). Maximal atrial inflow velocity decreased (-7.8 +/- 10.9 cm . s(-1), P less tha n or equal to 0.01) only in the trainers possibly because of a reducti on in resting heart rate (-6 +/- 11 beats . m(-1), P less than or equa l to 0.05). Acceleration and deceleration times were unchanged in both groups. These results demonstrate that substantial increases in exerc ise performance and exercise cardiac output can occur without detectab le changes in resting cardiac dimensions or left ventricular systolic and diastolic function.