[Behavior of arterial pressure during sports activity: track running].

In 6 normotensive and 14 borderline or mild hypertensive runners the intraarterial blood pressure (BP) changes determined by a maximal bicycle ergometric test and by an exhaustive run performed in outdoor conditions were recorded by means of the portable Oxford system. During running systolic BP attained higher values than during bicycle ergometry, while diastolic BP decreased during running and remained unchanged during ergometry. The highest BP values were recorded soon after starting running, then they progressively declined to increase once again during the final sprinting. Beat to beat analysis of the pressure tracings showed a peculiar pattern of the phasic waves throughout the run: continuous cyclic oscillations of pulse pressure were detected, as the variations of systolic blood pressure were not paralleled by those of the diastolic. The frequency of these rhythmic oscillations varied from 6-7 to 24-27/minute and was not related to respiration rate. The shape of these oscillations prompted us to investigate whether they were due to the "beat" phenomenon, that is to the combined effect of two waves with a nearly equal frequency. To verify this hypothesis 10 athletes during the run carried around the chest a Teruflex container filled with saline. The amplitude of the BP changes recorded in the container ranged from +/- 10 to +/- 50 mmHg. They were added by means of a computer to the BP tracing recorded during bicycle ergometry. The resultant wave was similar to that recorded in the radial artery during running.(ABSTRACT TRUNCATED AT 250 WORDS)