To evaluate the effect of exercise on left ventricular diastolic filling, the following were measured at rest and during exercise in 14 control subjects and 15 athletes, using digitized M-mode echocardiography: the peak early diastolic lengthening rate of the left ventricular dimension and the filling volume and the filling fraction during the first 0.10 s of diastole. During ergometer exercise performed at a level that increased the heart rate to 100 beats/min, there were significant increases in the peak normalized lengthening rate of the left ventricular dimension (control subjects, 4.2 +/- 1.3 vs. 6.1 +/- 1.1 s-1, mean +/- SD, P less than 0.001; athletes, 5.3 +/- 0.9 vs. 7.4 +/- 1.1 s-1, P less than 0.001), filling volume (control subjects, 15 +/- 12 vs. 33 +/- 10 ml, P less than 0.001; athletes, 21 +/- 12 vs. 63 +/- 18 ml, P less than 0.001), and filling fraction (control subjects, 21 +/- 14 vs. 42 +/- 17%, P less than 0.005; athletes, 21 +/- 13 vs. 54 +/- 12%, P less than 0.01). The peak lengthening rate of the left ventricular dimension, the filling volume, and the filling fraction were significantly greater in athletes than in control subjects during exercise (P less than 0.005, P less than 0.001, and P less than 0.05, respectively). Augmented early diastolic filling may be a mechanism to provide adequate filling for the ventricle at high heart rates produced by exercise, especially in athletes.

To study the effect of physical activity level on the distensibility of the human aortic wall, aortic pulse wave velocity (APWV) was estimated in 139 healthy male subjects (19-67 years) and was related to the energy expenditure by habitual physical exercise (physical activity index: PAI), which was evaluated by a 7-day total activity recall. The subjects consisted of 56 fun runners (runner group) and 83 general subjects, who were divided into 25 active subjects (active group: PAI > or = 1,500 kcal/week) and 58 sedentary subjects (sedentary group: PAI < 1,500 kcal/week). The APWV index (APWVI: standardized APWV by the diastolic blood pressure) was found to be positively correlated with age and was negatively correlated with PAI. The age-adjusted APWVI of the runner group was significantly lower than that of the active and sedentary groups. The age-adjusted APWVI was also significantly lower in the active group than in the sedentary group. These results suggest that increased physical activity may retard the age-dependent loss of arterial distensibility in humans, in proportion to the amount and/or intensity of exercise.

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