The objective of this trial was to evaluate whether cardiovascular vagal-sympathetic relationship, which is expected to be decreased in the elderly, can be modified by physical activity performed in advanced age. Cardiovascular autonomic function, as assessed by heart rate and arterial blood pressure during lying to standing, deep breathing, handgrip isometric stress test and Valsalva manoeuver, was estimated through Ewing's test in 10 sedentary healthy elderly subjects (mean age 68 +/- 3.1) compared to 10 long-distance runners of the same age (mean age 69 +/- 4.6). The endurance athletes, suitable for competition, had been practicing sport activity for a long time. Moreover in order to evaluate the influence of physical activity on cardiovascular response to exertion in the elderly all subjects were submitted to maximal electrocardiographic exercise test on a cycloergometer (multistage program with 30 watt x 3 min. steps). Heart rate, arterial systolic and diastolic blood pressure were recorded; double product was calculated at baseline; furthermore, total and maximal watts were recorded. For each of the parameters, Student's "t" test for independent observations was used in order to evaluate statistical differences among the two groups. Our data exhibited better results in cardiovascular reflex response due to parasympathetic (Valsalva and deep breathing test) neurovegetative modulation in the trained subjects with respect to the sedentary controls: Valsalva ratio (VR) = 2.04 +/- 0.44 vs 1.40 +/- 0.18 p < 0.001); deep breathing test (FC) = 23.6 +/- 6.2 vs 15.1 +/- 2.5 p < 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)